mirror of
https://github.com/saitohirga/WSJT-X.git
synced 2026-06-02 05:54:41 -04:00
Squashed 'boost/' content from commit b4feb19f2
git-subtree-dir: boost git-subtree-split: b4feb19f287ee92d87a9624b5d36b7cf46aeadeb
This commit is contained in:
Bill Somerville
@@ -0,0 +1,102 @@
|
||||
<html>
|
||||
<head>
|
||||
<meta http-equiv="Content-Type" content="text/html; charset=US-ASCII">
|
||||
<title>Mathematically Undefined Function Policies</title>
|
||||
<link rel="stylesheet" href="../../math.css" type="text/css">
|
||||
<meta name="generator" content="DocBook XSL Stylesheets V1.79.1">
|
||||
<link rel="home" href="../../index.html" title="Math Toolkit 2.5.1">
|
||||
<link rel="up" href="../pol_ref.html" title="Policy Reference">
|
||||
<link rel="prev" href="internal_promotion.html" title="Internal Floating-point Promotion Policies">
|
||||
<link rel="next" href="discrete_quant_ref.html" title="Discrete Quantile Policies">
|
||||
</head>
|
||||
<body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF">
|
||||
<table cellpadding="2" width="100%"><tr>
|
||||
<td valign="top"><img alt="Boost C++ Libraries" width="277" height="86" src="../../../../../../boost.png"></td>
|
||||
<td align="center"><a href="../../../../../../index.html">Home</a></td>
|
||||
<td align="center"><a href="../../../../../../libs/libraries.htm">Libraries</a></td>
|
||||
<td align="center"><a href="http://www.boost.org/users/people.html">People</a></td>
|
||||
<td align="center"><a href="http://www.boost.org/users/faq.html">FAQ</a></td>
|
||||
<td align="center"><a href="../../../../../../more/index.htm">More</a></td>
|
||||
</tr></table>
|
||||
<hr>
|
||||
<div class="spirit-nav">
|
||||
<a accesskey="p" href="internal_promotion.html"><img src="../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../pol_ref.html"><img src="../../../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../../index.html"><img src="../../../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="discrete_quant_ref.html"><img src="../../../../../../doc/src/images/next.png" alt="Next"></a>
|
||||
</div>
|
||||
<div class="section">
|
||||
<div class="titlepage"><div><div><h3 class="title">
|
||||
<a name="math_toolkit.pol_ref.assert_undefined"></a><a class="link" href="assert_undefined.html" title="Mathematically Undefined Function Policies">Mathematically
|
||||
Undefined Function Policies</a>
|
||||
</h3></div></div></div>
|
||||
<p>
|
||||
There are some functions that are generic (they are present for all the statistical
|
||||
distributions supported) but which may be mathematically undefined for certain
|
||||
distributions, but defined for others.
|
||||
</p>
|
||||
<p>
|
||||
For example, the Cauchy distribution does not have a meaningful mean, so
|
||||
what should
|
||||
</p>
|
||||
<pre class="programlisting"><span class="identifier">mean</span><span class="special">(</span><span class="identifier">cauchy</span><span class="special"><>());</span>
|
||||
</pre>
|
||||
<p>
|
||||
return, and should such an expression even compile at all?
|
||||
</p>
|
||||
<p>
|
||||
The default behaviour is for all such functions to not compile at all - in
|
||||
fact they will raise a <a href="http://www.boost.org/libs/static_assert/index.html" target="_top">static
|
||||
assertion</a> - but by changing the policy we can have them return the
|
||||
result of a domain error instead (which may well throw an exception, depending
|
||||
on the error handling policy).
|
||||
</p>
|
||||
<p>
|
||||
This behaviour is controlled by the <code class="computeroutput"><span class="identifier">assert_undefined</span><span class="special"><></span></code> policy:
|
||||
</p>
|
||||
<pre class="programlisting"><span class="keyword">namespace</span> <span class="identifier">boost</span><span class="special">{</span> <span class="keyword">namespace</span> <span class="identifier">math</span><span class="special">{</span> <span class="keyword">namespace</span> <span class="identifier">policies</span> <span class="special">{</span>
|
||||
|
||||
<span class="keyword">template</span> <span class="special"><</span><span class="keyword">bool</span> <span class="identifier">b</span><span class="special">></span>
|
||||
<span class="keyword">class</span> <span class="identifier">assert_undefined</span><span class="special">;</span>
|
||||
|
||||
<span class="special">}}}</span> <span class="comment">//namespaces</span>
|
||||
</pre>
|
||||
<p>
|
||||
For example:
|
||||
</p>
|
||||
<pre class="programlisting"><span class="preprocessor">#include</span> <span class="special"><</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">math</span><span class="special">/</span><span class="identifier">distributions</span><span class="special">/</span><span class="identifier">cauchy</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">></span>
|
||||
|
||||
<span class="keyword">using</span> <span class="keyword">namespace</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">math</span><span class="special">::</span><span class="identifier">policies</span><span class="special">;</span>
|
||||
<span class="keyword">using</span> <span class="keyword">namespace</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">math</span><span class="special">;</span>
|
||||
|
||||
<span class="comment">// This will not compile, cauchy has no mean!</span>
|
||||
<span class="keyword">double</span> <span class="identifier">m1</span> <span class="special">=</span> <span class="identifier">mean</span><span class="special">(</span><span class="identifier">cauchy</span><span class="special">());</span>
|
||||
|
||||
<span class="comment">// This will compile, but raises a domain error!</span>
|
||||
<span class="keyword">double</span> <span class="identifier">m2</span> <span class="special">=</span> <span class="identifier">mean</span><span class="special">(</span><span class="identifier">cauchy_distribution</span><span class="special"><</span><span class="keyword">double</span><span class="special">,</span> <span class="identifier">policy</span><span class="special"><</span><span class="identifier">assert_undefined</span><span class="special"><</span><span class="keyword">false</span><span class="special">></span> <span class="special">></span> <span class="special">>());</span>
|
||||
</pre>
|
||||
<p>
|
||||
<code class="computeroutput"><span class="identifier">policy</span><span class="special"><</span><span class="identifier">assert_undefined</span><span class="special"><</span><span class="keyword">false</span><span class="special">></span></code>
|
||||
behaviour can also be obtained by defining the macro
|
||||
</p>
|
||||
<pre class="programlisting"><span class="preprocessor">#define</span> <span class="identifier">BOOST_MATH_ASSERT_UNDEFINED_POLICY</span> <span class="keyword">false</span>
|
||||
</pre>
|
||||
<p>
|
||||
at the head of the file - see <a class="link" href="policy_defaults.html" title="Using Macros to Change the Policy Defaults">Using
|
||||
Macros to Change the Policy Defaults</a>.
|
||||
</p>
|
||||
</div>
|
||||
<table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr>
|
||||
<td align="left"></td>
|
||||
<td align="right"><div class="copyright-footer">Copyright © 2006-2010, 2012-2014 Nikhar Agrawal,
|
||||
Anton Bikineev, Paul A. Bristow, Marco Guazzone, Christopher Kormanyos, Hubert
|
||||
Holin, Bruno Lalande, John Maddock, Jeremy Murphy, Johan Råde, Gautam Sewani,
|
||||
Benjamin Sobotta, Thijs van den Berg, Daryle Walker and Xiaogang Zhang<p>
|
||||
Distributed under the Boost Software License, Version 1.0. (See accompanying
|
||||
file LICENSE_1_0.txt or copy at <a href="http://www.boost.org/LICENSE_1_0.txt" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>)
|
||||
</p>
|
||||
</div></td>
|
||||
</tr></table>
|
||||
<hr>
|
||||
<div class="spirit-nav">
|
||||
<a accesskey="p" href="internal_promotion.html"><img src="../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../pol_ref.html"><img src="../../../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../../index.html"><img src="../../../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="discrete_quant_ref.html"><img src="../../../../../../doc/src/images/next.png" alt="Next"></a>
|
||||
</div>
|
||||
</body>
|
||||
</html>
|
||||
@@ -0,0 +1,252 @@
|
||||
<html>
|
||||
<head>
|
||||
<meta http-equiv="Content-Type" content="text/html; charset=US-ASCII">
|
||||
<title>Discrete Quantile Policies</title>
|
||||
<link rel="stylesheet" href="../../math.css" type="text/css">
|
||||
<meta name="generator" content="DocBook XSL Stylesheets V1.79.1">
|
||||
<link rel="home" href="../../index.html" title="Math Toolkit 2.5.1">
|
||||
<link rel="up" href="../pol_ref.html" title="Policy Reference">
|
||||
<link rel="prev" href="assert_undefined.html" title="Mathematically Undefined Function Policies">
|
||||
<link rel="next" href="precision_pol.html" title="Precision Policies">
|
||||
</head>
|
||||
<body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF">
|
||||
<table cellpadding="2" width="100%"><tr>
|
||||
<td valign="top"><img alt="Boost C++ Libraries" width="277" height="86" src="../../../../../../boost.png"></td>
|
||||
<td align="center"><a href="../../../../../../index.html">Home</a></td>
|
||||
<td align="center"><a href="../../../../../../libs/libraries.htm">Libraries</a></td>
|
||||
<td align="center"><a href="http://www.boost.org/users/people.html">People</a></td>
|
||||
<td align="center"><a href="http://www.boost.org/users/faq.html">FAQ</a></td>
|
||||
<td align="center"><a href="../../../../../../more/index.htm">More</a></td>
|
||||
</tr></table>
|
||||
<hr>
|
||||
<div class="spirit-nav">
|
||||
<a accesskey="p" href="assert_undefined.html"><img src="../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../pol_ref.html"><img src="../../../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../../index.html"><img src="../../../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="precision_pol.html"><img src="../../../../../../doc/src/images/next.png" alt="Next"></a>
|
||||
</div>
|
||||
<div class="section">
|
||||
<div class="titlepage"><div><div><h3 class="title">
|
||||
<a name="math_toolkit.pol_ref.discrete_quant_ref"></a><a class="link" href="discrete_quant_ref.html" title="Discrete Quantile Policies">Discrete Quantile
|
||||
Policies</a>
|
||||
</h3></div></div></div>
|
||||
<p>
|
||||
If a statistical distribution is <span class="emphasis"><em>discrete</em></span> then the random
|
||||
variable can only have integer values - this leaves us with a problem when
|
||||
calculating quantiles - we can either ignore the discreteness of the distribution
|
||||
and return a real value, or we can round to an integer. As it happens, computing
|
||||
integer values can be substantially faster than calculating a real value,
|
||||
so there are definite advantages to returning an integer, but we do then
|
||||
need to decide how best to round the result. The <code class="computeroutput"><span class="identifier">discrete_quantile</span></code>
|
||||
policy defines how discrete quantiles work, and how integer results are rounded:
|
||||
</p>
|
||||
<pre class="programlisting"><span class="keyword">enum</span> <span class="identifier">discrete_quantile_policy_type</span>
|
||||
<span class="special">{</span>
|
||||
<span class="identifier">real</span><span class="special">,</span>
|
||||
<span class="identifier">integer_round_outwards</span><span class="special">,</span> <span class="comment">// default</span>
|
||||
<span class="identifier">integer_round_inwards</span><span class="special">,</span>
|
||||
<span class="identifier">integer_round_down</span><span class="special">,</span>
|
||||
<span class="identifier">integer_round_up</span><span class="special">,</span>
|
||||
<span class="identifier">integer_round_nearest</span>
|
||||
<span class="special">};</span>
|
||||
|
||||
<span class="keyword">template</span> <span class="special"><</span><span class="identifier">discrete_quantile_policy_type</span><span class="special">></span>
|
||||
<span class="keyword">struct</span> <span class="identifier">discrete_quantile</span><span class="special">;</span>
|
||||
</pre>
|
||||
<p>
|
||||
The values that <code class="computeroutput"><span class="identifier">discrete_quantile</span></code>
|
||||
can take have the following meanings:
|
||||
</p>
|
||||
<h6>
|
||||
<a name="math_toolkit.pol_ref.discrete_quant_ref.h0"></a>
|
||||
<span class="phrase"><a name="math_toolkit.pol_ref.discrete_quant_ref.real"></a></span><a class="link" href="discrete_quant_ref.html#math_toolkit.pol_ref.discrete_quant_ref.real">real</a>
|
||||
</h6>
|
||||
<p>
|
||||
Ignores the discreteness of the distribution, and returns a real-valued result.
|
||||
For example:
|
||||
</p>
|
||||
<pre class="programlisting"><span class="preprocessor">#include</span> <span class="special"><</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">math</span><span class="special">/</span><span class="identifier">distributions</span><span class="special">/</span><span class="identifier">negative_binomial</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">></span>
|
||||
<span class="keyword">using</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">math</span><span class="special">::</span><span class="identifier">negative_binomial_distribution</span><span class="special">;</span>
|
||||
|
||||
<span class="keyword">using</span> <span class="keyword">namespace</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">math</span><span class="special">::</span><span class="identifier">policies</span><span class="special">;</span>
|
||||
|
||||
<span class="keyword">typedef</span> <span class="identifier">negative_binomial_distribution</span><span class="special"><</span>
|
||||
<span class="keyword">double</span><span class="special">,</span>
|
||||
<span class="identifier">policy</span><span class="special"><</span><span class="identifier">discrete_quantile</span><span class="special"><</span><span class="identifier">real</span><span class="special">></span> <span class="special">></span>
|
||||
<span class="special">></span> <span class="identifier">dist_type</span><span class="special">;</span>
|
||||
|
||||
<span class="comment">// Lower 5% quantile:</span>
|
||||
<span class="keyword">double</span> <span class="identifier">x</span> <span class="special">=</span> <span class="identifier">quantile</span><span class="special">(</span><span class="identifier">dist_type</span><span class="special">(</span><span class="number">20</span><span class="special">,</span> <span class="number">0.3</span><span class="special">),</span> <span class="number">0.05</span><span class="special">);</span>
|
||||
<span class="comment">// Upper 95% quantile:</span>
|
||||
<span class="keyword">double</span> <span class="identifier">y</span> <span class="special">=</span> <span class="identifier">quantile</span><span class="special">(</span><span class="identifier">complement</span><span class="special">(</span><span class="identifier">dist_type</span><span class="special">(</span><span class="number">20</span><span class="special">,</span> <span class="number">0.3</span><span class="special">),</span> <span class="number">0.05</span><span class="special">));</span>
|
||||
</pre>
|
||||
<p>
|
||||
Results in <code class="computeroutput"><span class="identifier">x</span> <span class="special">=</span>
|
||||
<span class="number">27.3898</span></code> and <code class="computeroutput"><span class="identifier">y</span>
|
||||
<span class="special">=</span> <span class="number">68.1584</span></code>.
|
||||
</p>
|
||||
<h6>
|
||||
<a name="math_toolkit.pol_ref.discrete_quant_ref.h1"></a>
|
||||
<span class="phrase"><a name="math_toolkit.pol_ref.discrete_quant_ref.integer_round_outwards"></a></span><a class="link" href="discrete_quant_ref.html#math_toolkit.pol_ref.discrete_quant_ref.integer_round_outwards">integer_round_outwards</a>
|
||||
</h6>
|
||||
<p>
|
||||
This is the default policy: an integer value is returned so that:
|
||||
</p>
|
||||
<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; ">
|
||||
<li class="listitem">
|
||||
Lower quantiles (where the probability is less than 0.5) are rounded
|
||||
down.
|
||||
</li>
|
||||
<li class="listitem">
|
||||
Upper quantiles (where the probability is greater than 0.5) are rounded
|
||||
up.
|
||||
</li>
|
||||
</ul></div>
|
||||
<p>
|
||||
This is normally the safest rounding policy, since it ensures that both one
|
||||
and two sided intervals are guaranteed to have <span class="emphasis"><em>at least</em></span>
|
||||
the requested coverage. For example:
|
||||
</p>
|
||||
<pre class="programlisting"><span class="preprocessor">#include</span> <span class="special"><</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">math</span><span class="special">/</span><span class="identifier">distributions</span><span class="special">/</span><span class="identifier">negative_binomial</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">></span>
|
||||
<span class="keyword">using</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">math</span><span class="special">::</span><span class="identifier">negative_binomial</span><span class="special">;</span>
|
||||
|
||||
<span class="comment">// Use the default rounding policy integer_round_outwards.</span>
|
||||
<span class="comment">// Lower quantile rounded down:</span>
|
||||
<span class="keyword">double</span> <span class="identifier">x</span> <span class="special">=</span> <span class="identifier">quantile</span><span class="special">(</span><span class="identifier">negative_binomial</span><span class="special">(</span><span class="number">20</span><span class="special">,</span> <span class="number">0.3</span><span class="special">),</span> <span class="number">0.05</span><span class="special">);</span> <span class="comment">// rounded up 27 from 27.3898</span>
|
||||
<span class="comment">// Upper quantile rounded up:</span>
|
||||
<span class="keyword">double</span> <span class="identifier">y</span> <span class="special">=</span> <span class="identifier">quantile</span><span class="special">(</span><span class="identifier">complement</span><span class="special">(</span><span class="identifier">negative_binomial</span><span class="special">(</span><span class="number">20</span><span class="special">,</span> <span class="number">0.3</span><span class="special">),</span> <span class="number">0.05</span><span class="special">));</span> <span class="comment">// rounded down to 69 from 68.1584</span>
|
||||
</pre>
|
||||
<p>
|
||||
Results in <code class="computeroutput"><span class="identifier">x</span> <span class="special">=</span>
|
||||
<span class="number">27</span></code> (rounded down from 27.3898) and
|
||||
<code class="computeroutput"><span class="identifier">y</span> <span class="special">=</span>
|
||||
<span class="number">69</span></code> (rounded up from 68.1584).
|
||||
</p>
|
||||
<p>
|
||||
The variables x and y are now defined so that:
|
||||
</p>
|
||||
<pre class="programlisting"><span class="identifier">cdf</span><span class="special">(</span><span class="identifier">negative_binomial</span><span class="special">(</span><span class="number">20</span><span class="special">),</span> <span class="identifier">x</span><span class="special">)</span> <span class="special"><=</span> <span class="number">0.05</span>
|
||||
<span class="identifier">cdf</span><span class="special">(</span><span class="identifier">negative_binomial</span><span class="special">(</span><span class="number">20</span><span class="special">),</span> <span class="identifier">y</span><span class="special">)</span> <span class="special">>=</span> <span class="number">0.95</span>
|
||||
</pre>
|
||||
<p>
|
||||
In other words we guarantee <span class="emphasis"><em>at least 90% coverage in the central
|
||||
region overall</em></span>, and also <span class="emphasis"><em>no more than 5% coverage in
|
||||
each tail</em></span>.
|
||||
</p>
|
||||
<h6>
|
||||
<a name="math_toolkit.pol_ref.discrete_quant_ref.h2"></a>
|
||||
<span class="phrase"><a name="math_toolkit.pol_ref.discrete_quant_ref.integer_round_inwards"></a></span><a class="link" href="discrete_quant_ref.html#math_toolkit.pol_ref.discrete_quant_ref.integer_round_inwards">integer_round_inwards</a>
|
||||
</h6>
|
||||
<p>
|
||||
This is the opposite of <span class="emphasis"><em>integer_round_outwards</em></span>: an integer
|
||||
value is returned so that:
|
||||
</p>
|
||||
<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; ">
|
||||
<li class="listitem">
|
||||
Lower quantiles (where the probability is less than 0.5) are rounded
|
||||
<span class="emphasis"><em>up</em></span>.
|
||||
</li>
|
||||
<li class="listitem">
|
||||
Upper quantiles (where the probability is greater than 0.5) are rounded
|
||||
<span class="emphasis"><em>down</em></span>.
|
||||
</li>
|
||||
</ul></div>
|
||||
<p>
|
||||
For example:
|
||||
</p>
|
||||
<pre class="programlisting"><span class="preprocessor">#include</span> <span class="special"><</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">math</span><span class="special">/</span><span class="identifier">distributions</span><span class="special">/</span><span class="identifier">negative_binomial</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">></span>
|
||||
<span class="keyword">using</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">math</span><span class="special">::</span><span class="identifier">negative_binomial_distribution</span><span class="special">;</span>
|
||||
|
||||
<span class="keyword">using</span> <span class="keyword">namespace</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">math</span><span class="special">::</span><span class="identifier">policies</span><span class="special">;</span>
|
||||
|
||||
<span class="keyword">typedef</span> <span class="identifier">negative_binomial_distribution</span><span class="special"><</span>
|
||||
<span class="keyword">double</span><span class="special">,</span>
|
||||
<span class="identifier">policy</span><span class="special"><</span><span class="identifier">discrete_quantile</span><span class="special"><</span><span class="identifier">integer_round_inwards</span><span class="special">></span> <span class="special">></span>
|
||||
<span class="special">></span> <span class="identifier">dist_type</span><span class="special">;</span>
|
||||
|
||||
<span class="comment">// Lower quantile rounded up:</span>
|
||||
<span class="keyword">double</span> <span class="identifier">x</span> <span class="special">=</span> <span class="identifier">quantile</span><span class="special">(</span><span class="identifier">dist_type</span><span class="special">(</span><span class="number">20</span><span class="special">,</span> <span class="number">0.3</span><span class="special">),</span> <span class="number">0.05</span><span class="special">);</span> <span class="comment">// 28 rounded up from 27.3898</span>
|
||||
<span class="comment">// Upper quantile rounded down:</span>
|
||||
<span class="keyword">double</span> <span class="identifier">y</span> <span class="special">=</span> <span class="identifier">quantile</span><span class="special">(</span><span class="identifier">complement</span><span class="special">(</span><span class="identifier">dist_type</span><span class="special">(</span><span class="number">20</span><span class="special">,</span> <span class="number">0.3</span><span class="special">),</span> <span class="number">0.05</span><span class="special">));</span> <span class="comment">// 68 rounded down from 68.1584</span>
|
||||
</pre>
|
||||
<p>
|
||||
Results in <code class="computeroutput"><span class="identifier">x</span> <span class="special">=</span>
|
||||
<span class="number">28</span></code> (rounded up from 27.3898) and <code class="computeroutput"><span class="identifier">y</span> <span class="special">=</span> <span class="number">68</span></code>
|
||||
(rounded down from 68.1584).
|
||||
</p>
|
||||
<p>
|
||||
The variables x and y are now defined so that:
|
||||
</p>
|
||||
<pre class="programlisting"><span class="identifier">cdf</span><span class="special">(</span><span class="identifier">negative_binomial</span><span class="special">(</span><span class="number">20</span><span class="special">),</span> <span class="identifier">x</span><span class="special">)</span> <span class="special">>=</span> <span class="number">0.05</span>
|
||||
<span class="identifier">cdf</span><span class="special">(</span><span class="identifier">negative_binomial</span><span class="special">(</span><span class="number">20</span><span class="special">),</span> <span class="identifier">y</span><span class="special">)</span> <span class="special"><=</span> <span class="number">0.95</span>
|
||||
</pre>
|
||||
<p>
|
||||
In other words we guarantee <span class="emphasis"><em>at no more than 90% coverage in the
|
||||
central region overall</em></span>, and also <span class="emphasis"><em>at least 5% coverage
|
||||
in each tail</em></span>.
|
||||
</p>
|
||||
<h6>
|
||||
<a name="math_toolkit.pol_ref.discrete_quant_ref.h3"></a>
|
||||
<span class="phrase"><a name="math_toolkit.pol_ref.discrete_quant_ref.integer_round_down"></a></span><a class="link" href="discrete_quant_ref.html#math_toolkit.pol_ref.discrete_quant_ref.integer_round_down">integer_round_down</a>
|
||||
</h6>
|
||||
<p>
|
||||
Always rounds down to an integer value, no matter whether it's an upper or
|
||||
a lower quantile.
|
||||
</p>
|
||||
<h6>
|
||||
<a name="math_toolkit.pol_ref.discrete_quant_ref.h4"></a>
|
||||
<span class="phrase"><a name="math_toolkit.pol_ref.discrete_quant_ref.integer_round_up"></a></span><a class="link" href="discrete_quant_ref.html#math_toolkit.pol_ref.discrete_quant_ref.integer_round_up">integer_round_up</a>
|
||||
</h6>
|
||||
<p>
|
||||
Always rounds up to an integer value, no matter whether it's an upper or
|
||||
a lower quantile.
|
||||
</p>
|
||||
<h6>
|
||||
<a name="math_toolkit.pol_ref.discrete_quant_ref.h5"></a>
|
||||
<span class="phrase"><a name="math_toolkit.pol_ref.discrete_quant_ref.integer_round_nearest"></a></span><a class="link" href="discrete_quant_ref.html#math_toolkit.pol_ref.discrete_quant_ref.integer_round_nearest">integer_round_nearest</a>
|
||||
</h6>
|
||||
<p>
|
||||
Always rounds to the nearest integer value, no matter whether it's an upper
|
||||
or a lower quantile. This will produce the requested coverage <span class="emphasis"><em>in
|
||||
the average case</em></span>, but for any specific example may results in
|
||||
either significantly more or less coverage than the requested amount. For
|
||||
example:
|
||||
</p>
|
||||
<p>
|
||||
For example:
|
||||
</p>
|
||||
<pre class="programlisting"><span class="preprocessor">#include</span> <span class="special"><</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">math</span><span class="special">/</span><span class="identifier">distributions</span><span class="special">/</span><span class="identifier">negative_binomial</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">></span>
|
||||
<span class="keyword">using</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">math</span><span class="special">::</span><span class="identifier">negative_binomial_distribution</span><span class="special">;</span>
|
||||
|
||||
<span class="keyword">using</span> <span class="keyword">namespace</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">math</span><span class="special">::</span><span class="identifier">policies</span><span class="special">;</span>
|
||||
|
||||
<span class="keyword">typedef</span> <span class="identifier">negative_binomial_distribution</span><span class="special"><</span>
|
||||
<span class="keyword">double</span><span class="special">,</span>
|
||||
<span class="identifier">policy</span><span class="special"><</span><span class="identifier">discrete_quantile</span><span class="special"><</span><span class="identifier">integer_round_nearest</span><span class="special">></span> <span class="special">></span>
|
||||
<span class="special">></span> <span class="identifier">dist_type</span><span class="special">;</span>
|
||||
|
||||
<span class="comment">// Lower quantile rounded (down) to nearest:</span>
|
||||
<span class="keyword">double</span> <span class="identifier">x</span> <span class="special">=</span> <span class="identifier">quantile</span><span class="special">(</span><span class="identifier">dist_type</span><span class="special">(</span><span class="number">20</span><span class="special">,</span> <span class="number">0.3</span><span class="special">),</span> <span class="number">0.05</span><span class="special">);</span> <span class="comment">// 27</span>
|
||||
<span class="comment">// Upper quantile rounded (down) to nearest:</span>
|
||||
<span class="keyword">double</span> <span class="identifier">y</span> <span class="special">=</span> <span class="identifier">quantile</span><span class="special">(</span><span class="identifier">complement</span><span class="special">(</span><span class="identifier">dist_type</span><span class="special">(</span><span class="number">20</span><span class="special">,</span> <span class="number">0.3</span><span class="special">),</span> <span class="number">0.05</span><span class="special">));</span> <span class="comment">// 68</span>
|
||||
</pre>
|
||||
<p>
|
||||
Results in <code class="computeroutput"><span class="identifier">x</span> <span class="special">=</span>
|
||||
<span class="number">27</span></code> (rounded from 27.3898) and <code class="computeroutput"><span class="identifier">y</span> <span class="special">=</span> <span class="number">68</span></code>
|
||||
(rounded from 68.1584).
|
||||
</p>
|
||||
</div>
|
||||
<table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr>
|
||||
<td align="left"></td>
|
||||
<td align="right"><div class="copyright-footer">Copyright © 2006-2010, 2012-2014 Nikhar Agrawal,
|
||||
Anton Bikineev, Paul A. Bristow, Marco Guazzone, Christopher Kormanyos, Hubert
|
||||
Holin, Bruno Lalande, John Maddock, Jeremy Murphy, Johan Råde, Gautam Sewani,
|
||||
Benjamin Sobotta, Thijs van den Berg, Daryle Walker and Xiaogang Zhang<p>
|
||||
Distributed under the Boost Software License, Version 1.0. (See accompanying
|
||||
file LICENSE_1_0.txt or copy at <a href="http://www.boost.org/LICENSE_1_0.txt" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>)
|
||||
</p>
|
||||
</div></td>
|
||||
</tr></table>
|
||||
<hr>
|
||||
<div class="spirit-nav">
|
||||
<a accesskey="p" href="assert_undefined.html"><img src="../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../pol_ref.html"><img src="../../../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../../index.html"><img src="../../../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="precision_pol.html"><img src="../../../../../../doc/src/images/next.png" alt="Next"></a>
|
||||
</div>
|
||||
</body>
|
||||
</html>
|
||||
@@ -0,0 +1,773 @@
|
||||
<html>
|
||||
<head>
|
||||
<meta http-equiv="Content-Type" content="text/html; charset=US-ASCII">
|
||||
<title>Error Handling Policies</title>
|
||||
<link rel="stylesheet" href="../../math.css" type="text/css">
|
||||
<meta name="generator" content="DocBook XSL Stylesheets V1.79.1">
|
||||
<link rel="home" href="../../index.html" title="Math Toolkit 2.5.1">
|
||||
<link rel="up" href="../pol_ref.html" title="Policy Reference">
|
||||
<link rel="prev" href="../pol_ref.html" title="Policy Reference">
|
||||
<link rel="next" href="internal_promotion.html" title="Internal Floating-point Promotion Policies">
|
||||
</head>
|
||||
<body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF">
|
||||
<table cellpadding="2" width="100%"><tr>
|
||||
<td valign="top"><img alt="Boost C++ Libraries" width="277" height="86" src="../../../../../../boost.png"></td>
|
||||
<td align="center"><a href="../../../../../../index.html">Home</a></td>
|
||||
<td align="center"><a href="../../../../../../libs/libraries.htm">Libraries</a></td>
|
||||
<td align="center"><a href="http://www.boost.org/users/people.html">People</a></td>
|
||||
<td align="center"><a href="http://www.boost.org/users/faq.html">FAQ</a></td>
|
||||
<td align="center"><a href="../../../../../../more/index.htm">More</a></td>
|
||||
</tr></table>
|
||||
<hr>
|
||||
<div class="spirit-nav">
|
||||
<a accesskey="p" href="../pol_ref.html"><img src="../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../pol_ref.html"><img src="../../../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../../index.html"><img src="../../../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="internal_promotion.html"><img src="../../../../../../doc/src/images/next.png" alt="Next"></a>
|
||||
</div>
|
||||
<div class="section">
|
||||
<div class="titlepage"><div><div><h3 class="title">
|
||||
<a name="math_toolkit.pol_ref.error_handling_policies"></a><a class="link" href="error_handling_policies.html" title="Error Handling Policies">Error Handling
|
||||
Policies</a>
|
||||
</h3></div></div></div>
|
||||
<p>
|
||||
There are two orthogonal aspects to error handling:
|
||||
</p>
|
||||
<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; ">
|
||||
<li class="listitem">
|
||||
What to do (if anything) with the error.
|
||||
</li>
|
||||
<li class="listitem">
|
||||
What kind of error is being raised.
|
||||
</li>
|
||||
</ul></div>
|
||||
<h5>
|
||||
<a name="math_toolkit.pol_ref.error_handling_policies.h0"></a>
|
||||
<span class="phrase"><a name="math_toolkit.pol_ref.error_handling_policies.available_actions_when_an_error_"></a></span><a class="link" href="error_handling_policies.html#math_toolkit.pol_ref.error_handling_policies.available_actions_when_an_error_">Available
|
||||
Actions When an Error is Raised</a>
|
||||
</h5>
|
||||
<p>
|
||||
What to do with the error is encapsulated by an enumerated type:
|
||||
</p>
|
||||
<pre class="programlisting"><span class="keyword">namespace</span> <span class="identifier">boost</span> <span class="special">{</span> <span class="keyword">namespace</span> <span class="identifier">math</span> <span class="special">{</span> <span class="keyword">namespace</span> <span class="identifier">policies</span> <span class="special">{</span>
|
||||
|
||||
<span class="keyword">enum</span> <span class="identifier">error_policy_type</span>
|
||||
<span class="special">{</span>
|
||||
<span class="identifier">throw_on_error</span> <span class="special">=</span> <span class="number">0</span><span class="special">,</span> <span class="comment">// throw an exception.</span>
|
||||
<span class="identifier">errno_on_error</span> <span class="special">=</span> <span class="number">1</span><span class="special">,</span> <span class="comment">// set ::errno & return 0, NaN, infinity or best guess.</span>
|
||||
<span class="identifier">ignore_error</span> <span class="special">=</span> <span class="number">2</span><span class="special">,</span> <span class="comment">// return 0, NaN, infinity or best guess.</span>
|
||||
<span class="identifier">user_error</span> <span class="special">=</span> <span class="number">3</span> <span class="comment">// call a user-defined error handler.</span>
|
||||
<span class="special">};</span>
|
||||
|
||||
<span class="special">}}}</span> <span class="comment">// namespaces</span>
|
||||
</pre>
|
||||
<p>
|
||||
The various enumerated values have the following meanings:
|
||||
</p>
|
||||
<h6>
|
||||
<a name="math_toolkit.pol_ref.error_handling_policies.h1"></a>
|
||||
<span class="phrase"><a name="math_toolkit.pol_ref.error_handling_policies.throw_on_error"></a></span><a class="link" href="error_handling_policies.html#math_toolkit.pol_ref.error_handling_policies.throw_on_error">throw_on_error</a>
|
||||
</h6>
|
||||
<p>
|
||||
Will throw one of the following exceptions, depending upon the type of the
|
||||
error:
|
||||
</p>
|
||||
<div class="informaltable"><table class="table">
|
||||
<colgroup>
|
||||
<col>
|
||||
<col>
|
||||
</colgroup>
|
||||
<thead><tr>
|
||||
<th>
|
||||
<p>
|
||||
Error Type
|
||||
</p>
|
||||
</th>
|
||||
<th>
|
||||
<p>
|
||||
Exception
|
||||
</p>
|
||||
</th>
|
||||
</tr></thead>
|
||||
<tbody>
|
||||
<tr>
|
||||
<td>
|
||||
<p>
|
||||
Domain Error
|
||||
</p>
|
||||
</td>
|
||||
<td>
|
||||
<p>
|
||||
std::domain_error
|
||||
</p>
|
||||
</td>
|
||||
</tr>
|
||||
<tr>
|
||||
<td>
|
||||
<p>
|
||||
Pole Error
|
||||
</p>
|
||||
</td>
|
||||
<td>
|
||||
<p>
|
||||
std::domain_error
|
||||
</p>
|
||||
</td>
|
||||
</tr>
|
||||
<tr>
|
||||
<td>
|
||||
<p>
|
||||
Overflow Error
|
||||
</p>
|
||||
</td>
|
||||
<td>
|
||||
<p>
|
||||
std::overflow_error
|
||||
</p>
|
||||
</td>
|
||||
</tr>
|
||||
<tr>
|
||||
<td>
|
||||
<p>
|
||||
Underflow Error
|
||||
</p>
|
||||
</td>
|
||||
<td>
|
||||
<p>
|
||||
std::underflow_error
|
||||
</p>
|
||||
</td>
|
||||
</tr>
|
||||
<tr>
|
||||
<td>
|
||||
<p>
|
||||
Denorm Error
|
||||
</p>
|
||||
</td>
|
||||
<td>
|
||||
<p>
|
||||
std::underflow_error
|
||||
</p>
|
||||
</td>
|
||||
</tr>
|
||||
<tr>
|
||||
<td>
|
||||
<p>
|
||||
Evaluation Error
|
||||
</p>
|
||||
</td>
|
||||
<td>
|
||||
<p>
|
||||
boost::math::evaluation_error
|
||||
</p>
|
||||
</td>
|
||||
</tr>
|
||||
<tr>
|
||||
<td>
|
||||
<p>
|
||||
Indeterminate Result Error
|
||||
</p>
|
||||
</td>
|
||||
<td>
|
||||
<p>
|
||||
std::domain_error
|
||||
</p>
|
||||
</td>
|
||||
</tr>
|
||||
</tbody>
|
||||
</table></div>
|
||||
<h6>
|
||||
<a name="math_toolkit.pol_ref.error_handling_policies.h2"></a>
|
||||
<span class="phrase"><a name="math_toolkit.pol_ref.error_handling_policies.errno_on_error"></a></span><a class="link" href="error_handling_policies.html#math_toolkit.pol_ref.error_handling_policies.errno_on_error">errno_on_error</a>
|
||||
</h6>
|
||||
<p>
|
||||
Will set global <a href="http://en.wikipedia.org/wiki/Errno" target="_top"><code class="computeroutput"><span class="special">::</span><span class="identifier">errno</span></code></a>
|
||||
<code class="computeroutput"><span class="special">::</span><span class="identifier">errno</span></code>
|
||||
to one of the following values depending upon the error type (often EDOM
|
||||
= 33 and ERANGE = 34), and then return the same value as if the error had
|
||||
been ignored:
|
||||
</p>
|
||||
<div class="informaltable"><table class="table">
|
||||
<colgroup>
|
||||
<col>
|
||||
<col>
|
||||
</colgroup>
|
||||
<thead><tr>
|
||||
<th>
|
||||
<p>
|
||||
Error Type
|
||||
</p>
|
||||
</th>
|
||||
<th>
|
||||
<p>
|
||||
errno value
|
||||
</p>
|
||||
</th>
|
||||
</tr></thead>
|
||||
<tbody>
|
||||
<tr>
|
||||
<td>
|
||||
<p>
|
||||
Domain Error
|
||||
</p>
|
||||
</td>
|
||||
<td>
|
||||
<p>
|
||||
EDOM
|
||||
</p>
|
||||
</td>
|
||||
</tr>
|
||||
<tr>
|
||||
<td>
|
||||
<p>
|
||||
Pole Error
|
||||
</p>
|
||||
</td>
|
||||
<td>
|
||||
<p>
|
||||
EDOM
|
||||
</p>
|
||||
</td>
|
||||
</tr>
|
||||
<tr>
|
||||
<td>
|
||||
<p>
|
||||
Overflow Error
|
||||
</p>
|
||||
</td>
|
||||
<td>
|
||||
<p>
|
||||
ERANGE
|
||||
</p>
|
||||
</td>
|
||||
</tr>
|
||||
<tr>
|
||||
<td>
|
||||
<p>
|
||||
Underflow Error
|
||||
</p>
|
||||
</td>
|
||||
<td>
|
||||
<p>
|
||||
ERANGE
|
||||
</p>
|
||||
</td>
|
||||
</tr>
|
||||
<tr>
|
||||
<td>
|
||||
<p>
|
||||
Denorm Error
|
||||
</p>
|
||||
</td>
|
||||
<td>
|
||||
<p>
|
||||
ERANGE
|
||||
</p>
|
||||
</td>
|
||||
</tr>
|
||||
<tr>
|
||||
<td>
|
||||
<p>
|
||||
Evaluation Error
|
||||
</p>
|
||||
</td>
|
||||
<td>
|
||||
<p>
|
||||
EDOM
|
||||
</p>
|
||||
</td>
|
||||
</tr>
|
||||
<tr>
|
||||
<td>
|
||||
<p>
|
||||
Indeterminate Result Error
|
||||
</p>
|
||||
</td>
|
||||
<td>
|
||||
<p>
|
||||
EDOM
|
||||
</p>
|
||||
</td>
|
||||
</tr>
|
||||
</tbody>
|
||||
</table></div>
|
||||
<h6>
|
||||
<a name="math_toolkit.pol_ref.error_handling_policies.h3"></a>
|
||||
<span class="phrase"><a name="math_toolkit.pol_ref.error_handling_policies.ignore_error"></a></span><a class="link" href="error_handling_policies.html#math_toolkit.pol_ref.error_handling_policies.ignore_error">ignore_error</a>
|
||||
</h6>
|
||||
<p>
|
||||
Will return one of the values below depending on the error type (<code class="computeroutput"><span class="special">::</span><span class="identifier">errno</span></code>
|
||||
is NOT changed)::
|
||||
</p>
|
||||
<div class="informaltable"><table class="table">
|
||||
<colgroup>
|
||||
<col>
|
||||
<col>
|
||||
</colgroup>
|
||||
<thead><tr>
|
||||
<th>
|
||||
<p>
|
||||
Error Type
|
||||
</p>
|
||||
</th>
|
||||
<th>
|
||||
<p>
|
||||
Returned Value
|
||||
</p>
|
||||
</th>
|
||||
</tr></thead>
|
||||
<tbody>
|
||||
<tr>
|
||||
<td>
|
||||
<p>
|
||||
Domain Error
|
||||
</p>
|
||||
</td>
|
||||
<td>
|
||||
<p>
|
||||
std::numeric_limits<T>::quiet_NaN()
|
||||
</p>
|
||||
</td>
|
||||
</tr>
|
||||
<tr>
|
||||
<td>
|
||||
<p>
|
||||
Pole Error
|
||||
</p>
|
||||
</td>
|
||||
<td>
|
||||
<p>
|
||||
std::numeric_limits<T>::quiet_NaN()
|
||||
</p>
|
||||
</td>
|
||||
</tr>
|
||||
<tr>
|
||||
<td>
|
||||
<p>
|
||||
Overflow Error
|
||||
</p>
|
||||
</td>
|
||||
<td>
|
||||
<p>
|
||||
std::numeric_limits<T>::infinity()
|
||||
</p>
|
||||
</td>
|
||||
</tr>
|
||||
<tr>
|
||||
<td>
|
||||
<p>
|
||||
Underflow Error
|
||||
</p>
|
||||
</td>
|
||||
<td>
|
||||
<p>
|
||||
0
|
||||
</p>
|
||||
</td>
|
||||
</tr>
|
||||
<tr>
|
||||
<td>
|
||||
<p>
|
||||
Denorm Error
|
||||
</p>
|
||||
</td>
|
||||
<td>
|
||||
<p>
|
||||
The denormalised value.
|
||||
</p>
|
||||
</td>
|
||||
</tr>
|
||||
<tr>
|
||||
<td>
|
||||
<p>
|
||||
Evaluation Error
|
||||
</p>
|
||||
</td>
|
||||
<td>
|
||||
<p>
|
||||
The best guess (perhaps NaN) as to the result: which may be significantly
|
||||
in error.
|
||||
</p>
|
||||
</td>
|
||||
</tr>
|
||||
<tr>
|
||||
<td>
|
||||
<p>
|
||||
Indeterminate Result Error
|
||||
</p>
|
||||
</td>
|
||||
<td>
|
||||
<p>
|
||||
Depends on the function where the error occurred
|
||||
</p>
|
||||
</td>
|
||||
</tr>
|
||||
</tbody>
|
||||
</table></div>
|
||||
<h6>
|
||||
<a name="math_toolkit.pol_ref.error_handling_policies.h4"></a>
|
||||
<span class="phrase"><a name="math_toolkit.pol_ref.error_handling_policies.user_error"></a></span><a class="link" href="error_handling_policies.html#math_toolkit.pol_ref.error_handling_policies.user_error">user_error</a>
|
||||
</h6>
|
||||
<p>
|
||||
Will call a user defined error handler: these are forward declared in boost/math/policies/error_handling.hpp,
|
||||
but the actual definitions must be provided by the user:
|
||||
</p>
|
||||
<pre class="programlisting"><span class="keyword">namespace</span> <span class="identifier">boost</span><span class="special">{</span> <span class="keyword">namespace</span> <span class="identifier">math</span><span class="special">{</span> <span class="keyword">namespace</span> <span class="identifier">policies</span><span class="special">{</span>
|
||||
|
||||
<span class="keyword">template</span> <span class="special"><</span><span class="keyword">class</span> <span class="identifier">T</span><span class="special">></span>
|
||||
<span class="identifier">T</span> <span class="identifier">user_domain_error</span><span class="special">(</span><span class="keyword">const</span> <span class="keyword">char</span><span class="special">*</span> <span class="identifier">function</span><span class="special">,</span> <span class="keyword">const</span> <span class="keyword">char</span><span class="special">*</span> <span class="identifier">message</span><span class="special">,</span> <span class="keyword">const</span> <span class="identifier">T</span><span class="special">&</span> <span class="identifier">val</span><span class="special">);</span>
|
||||
|
||||
<span class="keyword">template</span> <span class="special"><</span><span class="keyword">class</span> <span class="identifier">T</span><span class="special">></span>
|
||||
<span class="identifier">T</span> <span class="identifier">user_pole_error</span><span class="special">(</span><span class="keyword">const</span> <span class="keyword">char</span><span class="special">*</span> <span class="identifier">function</span><span class="special">,</span> <span class="keyword">const</span> <span class="keyword">char</span><span class="special">*</span> <span class="identifier">message</span><span class="special">,</span> <span class="keyword">const</span> <span class="identifier">T</span><span class="special">&</span> <span class="identifier">val</span><span class="special">);</span>
|
||||
|
||||
<span class="keyword">template</span> <span class="special"><</span><span class="keyword">class</span> <span class="identifier">T</span><span class="special">></span>
|
||||
<span class="identifier">T</span> <span class="identifier">user_overflow_error</span><span class="special">(</span><span class="keyword">const</span> <span class="keyword">char</span><span class="special">*</span> <span class="identifier">function</span><span class="special">,</span> <span class="keyword">const</span> <span class="keyword">char</span><span class="special">*</span> <span class="identifier">message</span><span class="special">,</span> <span class="keyword">const</span> <span class="identifier">T</span><span class="special">&</span> <span class="identifier">val</span><span class="special">);</span>
|
||||
|
||||
<span class="keyword">template</span> <span class="special"><</span><span class="keyword">class</span> <span class="identifier">T</span><span class="special">></span>
|
||||
<span class="identifier">T</span> <span class="identifier">user_underflow_error</span><span class="special">(</span><span class="keyword">const</span> <span class="keyword">char</span><span class="special">*</span> <span class="identifier">function</span><span class="special">,</span> <span class="keyword">const</span> <span class="keyword">char</span><span class="special">*</span> <span class="identifier">message</span><span class="special">,</span> <span class="keyword">const</span> <span class="identifier">T</span><span class="special">&</span> <span class="identifier">val</span><span class="special">);</span>
|
||||
|
||||
<span class="keyword">template</span> <span class="special"><</span><span class="keyword">class</span> <span class="identifier">T</span><span class="special">></span>
|
||||
<span class="identifier">T</span> <span class="identifier">user_denorm_error</span><span class="special">(</span><span class="keyword">const</span> <span class="keyword">char</span><span class="special">*</span> <span class="identifier">function</span><span class="special">,</span> <span class="keyword">const</span> <span class="keyword">char</span><span class="special">*</span> <span class="identifier">message</span><span class="special">,</span> <span class="keyword">const</span> <span class="identifier">T</span><span class="special">&</span> <span class="identifier">val</span><span class="special">);</span>
|
||||
|
||||
<span class="keyword">template</span> <span class="special"><</span><span class="keyword">class</span> <span class="identifier">T</span><span class="special">></span>
|
||||
<span class="identifier">T</span> <span class="identifier">user_rounding_error</span><span class="special">(</span><span class="keyword">const</span> <span class="keyword">char</span><span class="special">*</span> <span class="identifier">function</span><span class="special">,</span> <span class="keyword">const</span> <span class="keyword">char</span><span class="special">*</span> <span class="identifier">message</span><span class="special">,</span> <span class="keyword">const</span> <span class="identifier">T</span><span class="special">&</span> <span class="identifier">val</span><span class="special">);</span>
|
||||
|
||||
<span class="keyword">template</span> <span class="special"><</span><span class="keyword">class</span> <span class="identifier">T</span><span class="special">></span>
|
||||
<span class="identifier">T</span> <span class="identifier">user_evaluation_error</span><span class="special">(</span><span class="keyword">const</span> <span class="keyword">char</span><span class="special">*</span> <span class="identifier">function</span><span class="special">,</span> <span class="keyword">const</span> <span class="keyword">char</span><span class="special">*</span> <span class="identifier">message</span><span class="special">,</span> <span class="keyword">const</span> <span class="identifier">T</span><span class="special">&</span> <span class="identifier">val</span><span class="special">);</span>
|
||||
|
||||
<span class="keyword">template</span> <span class="special"><</span><span class="keyword">class</span> <span class="identifier">T</span><span class="special">></span>
|
||||
<span class="identifier">T</span> <span class="identifier">user_indeterminate_result_error</span><span class="special">(</span><span class="keyword">const</span> <span class="keyword">char</span><span class="special">*</span> <span class="identifier">function</span><span class="special">,</span> <span class="keyword">const</span> <span class="keyword">char</span><span class="special">*</span> <span class="identifier">message</span><span class="special">,</span> <span class="keyword">const</span> <span class="identifier">T</span><span class="special">&</span> <span class="identifier">val</span><span class="special">);</span>
|
||||
|
||||
<span class="special">}}}</span> <span class="comment">// namespaces</span>
|
||||
</pre>
|
||||
<p>
|
||||
Note that the strings <span class="emphasis"><em>function</em></span> and <span class="emphasis"><em>message</em></span>
|
||||
may contain "%1%" format specifiers designed to be used in conjunction
|
||||
with Boost.Format. If these strings are to be presented to the program's
|
||||
end-user then the "%1%" format specifier should be replaced with
|
||||
the name of type T in the <span class="emphasis"><em>function</em></span> string, and if there
|
||||
is a %1% specifier in the <span class="emphasis"><em>message</em></span> string then it should
|
||||
be replaced with the value of <span class="emphasis"><em>val</em></span>.
|
||||
</p>
|
||||
<p>
|
||||
There is more information on user-defined error handlers in the <a class="link" href="../pol_tutorial/user_def_err_pol.html" title="Calling User Defined Error Handlers">tutorial
|
||||
here</a>.
|
||||
</p>
|
||||
<h5>
|
||||
<a name="math_toolkit.pol_ref.error_handling_policies.h5"></a>
|
||||
<span class="phrase"><a name="math_toolkit.pol_ref.error_handling_policies.kinds_of_error_raised"></a></span><a class="link" href="error_handling_policies.html#math_toolkit.pol_ref.error_handling_policies.kinds_of_error_raised">Kinds
|
||||
of Error Raised</a>
|
||||
</h5>
|
||||
<p>
|
||||
There are six kinds of error reported by this library, which are summarised
|
||||
in the following table:
|
||||
</p>
|
||||
<div class="informaltable"><table class="table">
|
||||
<colgroup>
|
||||
<col>
|
||||
<col>
|
||||
<col>
|
||||
</colgroup>
|
||||
<thead><tr>
|
||||
<th>
|
||||
<p>
|
||||
Error Type
|
||||
</p>
|
||||
</th>
|
||||
<th>
|
||||
<p>
|
||||
Policy Class
|
||||
</p>
|
||||
</th>
|
||||
<th>
|
||||
<p>
|
||||
Description
|
||||
</p>
|
||||
</th>
|
||||
</tr></thead>
|
||||
<tbody>
|
||||
<tr>
|
||||
<td>
|
||||
<p>
|
||||
Domain Error
|
||||
</p>
|
||||
</td>
|
||||
<td>
|
||||
<p>
|
||||
boost::math::policies::domain_error<<span class="emphasis"><em>action</em></span>>
|
||||
</p>
|
||||
</td>
|
||||
<td>
|
||||
<p>
|
||||
Raised when more or more arguments are outside the defined range
|
||||
of the function.
|
||||
</p>
|
||||
<p>
|
||||
Defaults to <code class="computeroutput"><span class="identifier">boost</span><span class="special">::</span><span class="identifier">math</span><span class="special">::</span><span class="identifier">policies</span><span class="special">::</span><span class="identifier">domain_error</span><span class="special"><</span><span class="identifier">throw_on_error</span><span class="special">></span></code>
|
||||
</p>
|
||||
<p>
|
||||
When the action is set to <span class="emphasis"><em>throw_on_error</em></span> then
|
||||
throws <code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">domain_error</span></code>
|
||||
</p>
|
||||
</td>
|
||||
</tr>
|
||||
<tr>
|
||||
<td>
|
||||
<p>
|
||||
Pole Error
|
||||
</p>
|
||||
</td>
|
||||
<td>
|
||||
<p>
|
||||
boost::math::policies::pole_error<<span class="emphasis"><em>action</em></span>>
|
||||
</p>
|
||||
</td>
|
||||
<td>
|
||||
<p>
|
||||
Raised when more or more arguments would cause the function to
|
||||
be evaluated at a pole.
|
||||
</p>
|
||||
<p>
|
||||
Defaults to <code class="computeroutput"><span class="identifier">boost</span><span class="special">::</span><span class="identifier">math</span><span class="special">::</span><span class="identifier">policies</span><span class="special">::</span><span class="identifier">pole_error</span><span class="special"><</span><span class="identifier">throw_on_error</span><span class="special">></span></code>
|
||||
</p>
|
||||
<p>
|
||||
When the action is <span class="emphasis"><em>throw_on_error</em></span> then throw
|
||||
a <code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">domain_error</span></code>
|
||||
</p>
|
||||
</td>
|
||||
</tr>
|
||||
<tr>
|
||||
<td>
|
||||
<p>
|
||||
Overflow Error
|
||||
</p>
|
||||
</td>
|
||||
<td>
|
||||
<p>
|
||||
boost::math::policies::overflow_error<<span class="emphasis"><em>action</em></span>>
|
||||
</p>
|
||||
</td>
|
||||
<td>
|
||||
<p>
|
||||
Raised when the result of the function is outside the representable
|
||||
range of the floating point type used.
|
||||
</p>
|
||||
<p>
|
||||
Defaults to <code class="computeroutput"><span class="identifier">boost</span><span class="special">::</span><span class="identifier">math</span><span class="special">::</span><span class="identifier">policies</span><span class="special">::</span><span class="identifier">overflow_error</span><span class="special"><</span><span class="identifier">throw_on_error</span><span class="special">></span></code>.
|
||||
</p>
|
||||
<p>
|
||||
When the action is <span class="emphasis"><em>throw_on_error</em></span> then throws
|
||||
a <code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">overflow_error</span></code>.
|
||||
</p>
|
||||
</td>
|
||||
</tr>
|
||||
<tr>
|
||||
<td>
|
||||
<p>
|
||||
Underflow Error
|
||||
</p>
|
||||
</td>
|
||||
<td>
|
||||
<p>
|
||||
boost::math::policies::underflow_error<<span class="emphasis"><em>action</em></span>>
|
||||
</p>
|
||||
</td>
|
||||
<td>
|
||||
<p>
|
||||
Raised when the result of the function is too small to be represented
|
||||
in the floating point type used.
|
||||
</p>
|
||||
<p>
|
||||
Defaults to <code class="computeroutput"><span class="identifier">boost</span><span class="special">::</span><span class="identifier">math</span><span class="special">::</span><span class="identifier">policies</span><span class="special">::</span><span class="identifier">underflow_error</span><span class="special"><</span><span class="identifier">ignore_error</span><span class="special">></span></code>
|
||||
</p>
|
||||
<p>
|
||||
When the specified action is <span class="emphasis"><em>throw_on_error</em></span>
|
||||
then throws a <code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">underflow_error</span></code>
|
||||
</p>
|
||||
</td>
|
||||
</tr>
|
||||
<tr>
|
||||
<td>
|
||||
<p>
|
||||
Denorm Error
|
||||
</p>
|
||||
</td>
|
||||
<td>
|
||||
<p>
|
||||
boost::math::policies::denorm_error<<span class="emphasis"><em>action</em></span>>
|
||||
</p>
|
||||
</td>
|
||||
<td>
|
||||
<p>
|
||||
Raised when the result of the function is a denormalised value.
|
||||
</p>
|
||||
<p>
|
||||
Defaults to <code class="computeroutput"><span class="identifier">boost</span><span class="special">::</span><span class="identifier">math</span><span class="special">::</span><span class="identifier">policies</span><span class="special">::</span><span class="identifier">denorm_error</span><span class="special"><</span><span class="identifier">ignore_error</span><span class="special">></span></code>
|
||||
</p>
|
||||
<p>
|
||||
When the action is <span class="emphasis"><em>throw_on_error</em></span> then throws
|
||||
a <code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">underflow_error</span></code>
|
||||
</p>
|
||||
</td>
|
||||
</tr>
|
||||
<tr>
|
||||
<td>
|
||||
<p>
|
||||
Rounding Error
|
||||
</p>
|
||||
</td>
|
||||
<td>
|
||||
<p>
|
||||
boost::math::policies::rounding_error<<span class="emphasis"><em>action</em></span>>
|
||||
</p>
|
||||
</td>
|
||||
<td>
|
||||
<p>
|
||||
Raised When one of the rounding functions <a class="link" href="../rounding/round.html" title="Rounding Functions">round</a>,
|
||||
<a class="link" href="../rounding/trunc.html" title="Truncation Functions">trunc</a> or <a class="link" href="../rounding/modf.html" title="Integer and Fractional Part Splitting (modf)">modf</a> is called with
|
||||
an argument that has no integer representation, or is too large
|
||||
to be represented in the result type
|
||||
</p>
|
||||
<p>
|
||||
Defaults to <code class="computeroutput"><span class="identifier">boost</span><span class="special">::</span><span class="identifier">math</span><span class="special">::</span><span class="identifier">policies</span><span class="special">::</span><span class="identifier">rounding_error</span><span class="special"><</span><span class="identifier">throw_on_error</span><span class="special">></span></code>
|
||||
</p>
|
||||
<p>
|
||||
When the action is <span class="emphasis"><em>throw_on_error</em></span> then throws
|
||||
<code class="computeroutput"><span class="identifier">boost</span><span class="special">::</span><span class="identifier">math</span><span class="special">::</span><span class="identifier">rounding_error</span></code>
|
||||
</p>
|
||||
</td>
|
||||
</tr>
|
||||
<tr>
|
||||
<td>
|
||||
<p>
|
||||
Evaluation Error
|
||||
</p>
|
||||
</td>
|
||||
<td>
|
||||
<p>
|
||||
boost::math::policies::evaluation_error<<span class="emphasis"><em>action</em></span>>
|
||||
</p>
|
||||
</td>
|
||||
<td>
|
||||
<p>
|
||||
Raised when the result of the function is well defined and finite,
|
||||
but we were unable to compute it. Typically this occurs when an
|
||||
iterative method fails to converge. Of course ideally this error
|
||||
should never be raised: feel free to report it as a bug if it is!
|
||||
</p>
|
||||
<p>
|
||||
Defaults to <code class="computeroutput"><span class="identifier">boost</span><span class="special">::</span><span class="identifier">math</span><span class="special">::</span><span class="identifier">policies</span><span class="special">::</span><span class="identifier">evaluation_error</span><span class="special"><</span><span class="identifier">throw_on_error</span><span class="special">></span></code>
|
||||
</p>
|
||||
<p>
|
||||
When the action is <span class="emphasis"><em>throw_on_error</em></span> then throws
|
||||
<code class="computeroutput"><span class="identifier">boost</span><span class="special">::</span><span class="identifier">math</span><span class="special">::</span><span class="identifier">evaluation_error</span></code>
|
||||
</p>
|
||||
</td>
|
||||
</tr>
|
||||
<tr>
|
||||
<td>
|
||||
<p>
|
||||
Indeterminate Result Error
|
||||
</p>
|
||||
</td>
|
||||
<td>
|
||||
<p>
|
||||
boost::math::policies::indeterminate_result_error<<span class="emphasis"><em>action</em></span>>
|
||||
</p>
|
||||
</td>
|
||||
<td>
|
||||
<p>
|
||||
Raised when the result of a function is not defined for the values
|
||||
that were passed to it.
|
||||
</p>
|
||||
<p>
|
||||
Defaults to <code class="computeroutput"><span class="identifier">boost</span><span class="special">::</span><span class="identifier">math</span><span class="special">::</span><span class="identifier">policies</span><span class="special">::</span><span class="identifier">indeterminate_result_error</span><span class="special"><</span><span class="identifier">ignore_error</span><span class="special">></span></code>
|
||||
</p>
|
||||
<p>
|
||||
When the action is <span class="emphasis"><em>throw_on_error</em></span> then throws
|
||||
<code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">domain_error</span></code>
|
||||
</p>
|
||||
</td>
|
||||
</tr>
|
||||
</tbody>
|
||||
</table></div>
|
||||
<h5>
|
||||
<a name="math_toolkit.pol_ref.error_handling_policies.h6"></a>
|
||||
<span class="phrase"><a name="math_toolkit.pol_ref.error_handling_policies.examples"></a></span><a class="link" href="error_handling_policies.html#math_toolkit.pol_ref.error_handling_policies.examples">Examples</a>
|
||||
</h5>
|
||||
<p>
|
||||
Suppose we want a call to <code class="computeroutput"><span class="identifier">tgamma</span></code>
|
||||
to behave in a C-compatible way and set global <code class="computeroutput"><span class="special">::</span><span class="identifier">errno</span></code> rather than throw an exception, we
|
||||
can achieve this at the call site using:
|
||||
</p>
|
||||
<pre class="programlisting"><span class="preprocessor">#include</span> <span class="special"><</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">math</span><span class="special">/</span><span class="identifier">special_functions</span><span class="special">/</span><span class="identifier">gamma</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">></span>
|
||||
<span class="keyword">using</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">math</span><span class="special">::</span><span class="identifier">tgamma</span><span class="special">;</span>
|
||||
|
||||
<span class="comment">//using namespace boost::math::policies; may also be convenient.</span>
|
||||
<span class="keyword">using</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">math</span><span class="special">::</span><span class="identifier">policies</span><span class="special">::</span><span class="identifier">policy</span><span class="special">;</span>
|
||||
<span class="keyword">using</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">math</span><span class="special">::</span><span class="identifier">policies</span><span class="special">::</span><span class="identifier">evaluation_error</span><span class="special">;</span>
|
||||
<span class="keyword">using</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">math</span><span class="special">::</span><span class="identifier">policies</span><span class="special">::</span><span class="identifier">domain_error</span><span class="special">;</span>
|
||||
<span class="keyword">using</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">math</span><span class="special">::</span><span class="identifier">policies</span><span class="special">::</span><span class="identifier">overflow_error</span><span class="special">;</span>
|
||||
<span class="keyword">using</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">math</span><span class="special">::</span><span class="identifier">policies</span><span class="special">::</span><span class="identifier">domain_error</span><span class="special">;</span>
|
||||
<span class="keyword">using</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">math</span><span class="special">::</span><span class="identifier">policies</span><span class="special">::</span><span class="identifier">pole_error</span><span class="special">;</span>
|
||||
<span class="keyword">using</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">math</span><span class="special">::</span><span class="identifier">policies</span><span class="special">::</span><span class="identifier">errno_on_error</span><span class="special">;</span>
|
||||
|
||||
<span class="comment">// Define a policy:</span>
|
||||
<span class="keyword">typedef</span> <span class="identifier">policy</span><span class="special"><</span>
|
||||
<span class="identifier">domain_error</span><span class="special"><</span><span class="identifier">errno_on_error</span><span class="special">>,</span>
|
||||
<span class="identifier">pole_error</span><span class="special"><</span><span class="identifier">errno_on_error</span><span class="special">>,</span>
|
||||
<span class="identifier">overflow_error</span><span class="special"><</span><span class="identifier">errno_on_error</span><span class="special">>,</span>
|
||||
<span class="identifier">evaluation_error</span><span class="special"><</span><span class="identifier">errno_on_error</span><span class="special">></span>
|
||||
<span class="special">></span> <span class="identifier">my_policy</span><span class="special">;</span>
|
||||
|
||||
<span class="keyword">double</span> <span class="identifier">my_value</span> <span class="special">=</span> <span class="number">0.</span><span class="special">;</span> <span class="comment">// </span>
|
||||
|
||||
<span class="comment">// Call the function applying my_policy:</span>
|
||||
<span class="keyword">double</span> <span class="identifier">t1</span> <span class="special">=</span> <span class="identifier">tgamma</span><span class="special">(</span><span class="identifier">my_value</span><span class="special">,</span> <span class="identifier">my_policy</span><span class="special">());</span>
|
||||
|
||||
<span class="comment">// Alternatively (and equivalently) we could use helpful function</span>
|
||||
<span class="comment">// make_policy and define everything at the call site:</span>
|
||||
<span class="keyword">double</span> <span class="identifier">t2</span> <span class="special">=</span> <span class="identifier">tgamma</span><span class="special">(</span><span class="identifier">my_value</span><span class="special">,</span>
|
||||
<span class="identifier">make_policy</span><span class="special">(</span>
|
||||
<span class="identifier">domain_error</span><span class="special"><</span><span class="identifier">errno_on_error</span><span class="special">>(),</span>
|
||||
<span class="identifier">pole_error</span><span class="special"><</span><span class="identifier">errno_on_error</span><span class="special">>(),</span>
|
||||
<span class="identifier">overflow_error</span><span class="special"><</span><span class="identifier">errno_on_error</span><span class="special">>(),</span>
|
||||
<span class="identifier">evaluation_error</span><span class="special"><</span><span class="identifier">errno_on_error</span><span class="special">>()</span> <span class="special">)</span>
|
||||
<span class="special">);</span>
|
||||
</pre>
|
||||
<p>
|
||||
Suppose we want a statistical distribution to return infinities, rather than
|
||||
throw exceptions, then we can use:
|
||||
</p>
|
||||
<pre class="programlisting"><span class="preprocessor">#include</span> <span class="special"><</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">math</span><span class="special">/</span><span class="identifier">distributions</span><span class="special">/</span><span class="identifier">normal</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">></span>
|
||||
<span class="keyword">using</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">math</span><span class="special">::</span><span class="identifier">normal_distribution</span><span class="special">;</span>
|
||||
|
||||
<span class="keyword">using</span> <span class="keyword">namespace</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">math</span><span class="special">::</span><span class="identifier">policies</span><span class="special">;</span>
|
||||
|
||||
<span class="comment">// Define a specific policy:</span>
|
||||
<span class="keyword">typedef</span> <span class="identifier">policy</span><span class="special"><</span>
|
||||
<span class="identifier">overflow_error</span><span class="special"><</span><span class="identifier">ignore_error</span><span class="special">></span>
|
||||
<span class="special">></span> <span class="identifier">my_policy</span><span class="special">;</span>
|
||||
|
||||
<span class="comment">// Define the distribution, using my_policy:</span>
|
||||
<span class="keyword">typedef</span> <span class="identifier">normal_distribution</span><span class="special"><</span><span class="keyword">double</span><span class="special">,</span> <span class="identifier">my_policy</span><span class="special">></span> <span class="identifier">my_norm</span><span class="special">;</span>
|
||||
|
||||
<span class="comment">// Construct a my_norm distribution, using default mean and standard deviation,</span>
|
||||
<span class="comment">// and get a 0.05 or 5% quantile:</span>
|
||||
<span class="keyword">double</span> <span class="identifier">q</span> <span class="special">=</span> <span class="identifier">quantile</span><span class="special">(</span><span class="identifier">my_norm</span><span class="special">(),</span> <span class="number">0.05</span><span class="special">);</span> <span class="comment">// = -1.64485</span>
|
||||
</pre>
|
||||
</div>
|
||||
<table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr>
|
||||
<td align="left"></td>
|
||||
<td align="right"><div class="copyright-footer">Copyright © 2006-2010, 2012-2014 Nikhar Agrawal,
|
||||
Anton Bikineev, Paul A. Bristow, Marco Guazzone, Christopher Kormanyos, Hubert
|
||||
Holin, Bruno Lalande, John Maddock, Jeremy Murphy, Johan Råde, Gautam Sewani,
|
||||
Benjamin Sobotta, Thijs van den Berg, Daryle Walker and Xiaogang Zhang<p>
|
||||
Distributed under the Boost Software License, Version 1.0. (See accompanying
|
||||
file LICENSE_1_0.txt or copy at <a href="http://www.boost.org/LICENSE_1_0.txt" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>)
|
||||
</p>
|
||||
</div></td>
|
||||
</tr></table>
|
||||
<hr>
|
||||
<div class="spirit-nav">
|
||||
<a accesskey="p" href="../pol_ref.html"><img src="../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../pol_ref.html"><img src="../../../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../../index.html"><img src="../../../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="internal_promotion.html"><img src="../../../../../../doc/src/images/next.png" alt="Next"></a>
|
||||
</div>
|
||||
</body>
|
||||
</html>
|
||||
@@ -0,0 +1,150 @@
|
||||
<html>
|
||||
<head>
|
||||
<meta http-equiv="Content-Type" content="text/html; charset=US-ASCII">
|
||||
<title>Internal Floating-point Promotion Policies</title>
|
||||
<link rel="stylesheet" href="../../math.css" type="text/css">
|
||||
<meta name="generator" content="DocBook XSL Stylesheets V1.79.1">
|
||||
<link rel="home" href="../../index.html" title="Math Toolkit 2.5.1">
|
||||
<link rel="up" href="../pol_ref.html" title="Policy Reference">
|
||||
<link rel="prev" href="error_handling_policies.html" title="Error Handling Policies">
|
||||
<link rel="next" href="assert_undefined.html" title="Mathematically Undefined Function Policies">
|
||||
</head>
|
||||
<body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF">
|
||||
<table cellpadding="2" width="100%"><tr>
|
||||
<td valign="top"><img alt="Boost C++ Libraries" width="277" height="86" src="../../../../../../boost.png"></td>
|
||||
<td align="center"><a href="../../../../../../index.html">Home</a></td>
|
||||
<td align="center"><a href="../../../../../../libs/libraries.htm">Libraries</a></td>
|
||||
<td align="center"><a href="http://www.boost.org/users/people.html">People</a></td>
|
||||
<td align="center"><a href="http://www.boost.org/users/faq.html">FAQ</a></td>
|
||||
<td align="center"><a href="../../../../../../more/index.htm">More</a></td>
|
||||
</tr></table>
|
||||
<hr>
|
||||
<div class="spirit-nav">
|
||||
<a accesskey="p" href="error_handling_policies.html"><img src="../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../pol_ref.html"><img src="../../../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../../index.html"><img src="../../../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="assert_undefined.html"><img src="../../../../../../doc/src/images/next.png" alt="Next"></a>
|
||||
</div>
|
||||
<div class="section">
|
||||
<div class="titlepage"><div><div><h3 class="title">
|
||||
<a name="math_toolkit.pol_ref.internal_promotion"></a><a class="link" href="internal_promotion.html" title="Internal Floating-point Promotion Policies">Internal Floating-point
|
||||
Promotion Policies</a>
|
||||
</h3></div></div></div>
|
||||
<p>
|
||||
Normally when evaluating a function at say <code class="computeroutput"><span class="keyword">float</span></code>
|
||||
precision, maximal accuracy is assured by conducting the calculation at
|
||||
<code class="computeroutput"><span class="keyword">double</span></code> precision internally,
|
||||
and then rounding the result. There are two policies that control whether
|
||||
internal promotion to a higher precision floating-point type takes place,
|
||||
or not:
|
||||
</p>
|
||||
<div class="informaltable"><table class="table">
|
||||
<colgroup>
|
||||
<col>
|
||||
<col>
|
||||
</colgroup>
|
||||
<thead><tr>
|
||||
<th>
|
||||
<p>
|
||||
Policy
|
||||
</p>
|
||||
</th>
|
||||
<th>
|
||||
<p>
|
||||
Meaning
|
||||
</p>
|
||||
</th>
|
||||
</tr></thead>
|
||||
<tbody>
|
||||
<tr>
|
||||
<td>
|
||||
<p>
|
||||
<code class="computeroutput"><span class="identifier">boost</span><span class="special">::</span><span class="identifier">math</span><span class="special">::</span><span class="identifier">policies</span><span class="special">::</span><span class="identifier">promote_float</span><span class="special"><</span><span class="identifier">B</span><span class="special">></span></code>
|
||||
</p>
|
||||
</td>
|
||||
<td>
|
||||
<p>
|
||||
Indicates whether <code class="computeroutput"><span class="keyword">float</span></code>
|
||||
arguments should be promoted to <code class="computeroutput"><span class="keyword">double</span></code>
|
||||
precision internally: defaults to <code class="computeroutput"><span class="identifier">boost</span><span class="special">::</span><span class="identifier">math</span><span class="special">::</span><span class="identifier">policies</span><span class="special">::</span><span class="identifier">promote_float</span><span class="special"><</span><span class="keyword">true</span><span class="special">></span></code>
|
||||
</p>
|
||||
</td>
|
||||
</tr>
|
||||
<tr>
|
||||
<td>
|
||||
<p>
|
||||
<code class="computeroutput"><span class="identifier">boost</span><span class="special">::</span><span class="identifier">math</span><span class="special">::</span><span class="identifier">policies</span><span class="special">::</span><span class="identifier">promote_double</span><span class="special"><</span><span class="identifier">B</span><span class="special">></span></code>
|
||||
</p>
|
||||
</td>
|
||||
<td>
|
||||
<p>
|
||||
Indicates whether <code class="computeroutput"><span class="keyword">double</span></code>
|
||||
arguments should be promoted to <code class="computeroutput"><span class="keyword">long</span>
|
||||
<span class="keyword">double</span></code> precision internally:
|
||||
defaults to <code class="computeroutput"><span class="identifier">boost</span><span class="special">::</span><span class="identifier">math</span><span class="special">::</span><span class="identifier">policies</span><span class="special">::</span><span class="identifier">promote_double</span><span class="special"><</span><span class="keyword">true</span><span class="special">></span></code>
|
||||
</p>
|
||||
</td>
|
||||
</tr>
|
||||
</tbody>
|
||||
</table></div>
|
||||
<h5>
|
||||
<a name="math_toolkit.pol_ref.internal_promotion.h0"></a>
|
||||
<span class="phrase"><a name="math_toolkit.pol_ref.internal_promotion.examples"></a></span><a class="link" href="internal_promotion.html#math_toolkit.pol_ref.internal_promotion.examples">Examples</a>
|
||||
</h5>
|
||||
<p>
|
||||
Suppose we want <code class="computeroutput"><span class="identifier">tgamma</span></code> to
|
||||
be evaluated without internal promotion to <code class="computeroutput"><span class="keyword">long</span>
|
||||
<span class="keyword">double</span></code>, then we could use:
|
||||
</p>
|
||||
<pre class="programlisting"><span class="preprocessor">#include</span> <span class="special"><</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">math</span><span class="special">/</span><span class="identifier">special_functions</span><span class="special">/</span><span class="identifier">gamma</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">></span>
|
||||
|
||||
<span class="keyword">using</span> <span class="keyword">namespace</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">math</span><span class="special">::</span><span class="identifier">policies</span><span class="special">;</span>
|
||||
<span class="keyword">using</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">math</span><span class="special">::</span><span class="identifier">tgamma</span><span class="special">;</span>
|
||||
|
||||
<span class="comment">// Define a new policy *not* internally promoting RealType to double:</span>
|
||||
<span class="keyword">typedef</span> <span class="identifier">policy</span><span class="special"><</span>
|
||||
<span class="identifier">promote_double</span><span class="special"><</span><span class="keyword">false</span><span class="special">></span>
|
||||
<span class="special">></span> <span class="identifier">my_policy</span><span class="special">;</span>
|
||||
|
||||
<span class="comment">// Call the function, applying the new policy:</span>
|
||||
<span class="keyword">double</span> <span class="identifier">t1</span> <span class="special">=</span> <span class="identifier">tgamma</span><span class="special">(</span><span class="identifier">some_value</span><span class="special">,</span> <span class="identifier">my_policy</span><span class="special">());</span>
|
||||
|
||||
<span class="comment">// Alternatively we could use helper function make_policy,</span>
|
||||
<span class="comment">// and concisely define everything at the call site:</span>
|
||||
<span class="keyword">double</span> <span class="identifier">t2</span> <span class="special">=</span> <span class="identifier">tgamma</span><span class="special">(</span><span class="identifier">some_value</span><span class="special">,</span> <span class="identifier">make_policy</span><span class="special">(</span><span class="identifier">promote_double</span><span class="special"><</span><span class="keyword">false</span><span class="special">>()));</span>
|
||||
</pre>
|
||||
<p>
|
||||
Alternatively, suppose we want a distribution to perform calculations without
|
||||
promoting <code class="computeroutput"><span class="keyword">float</span></code> to <code class="computeroutput"><span class="keyword">double</span></code>, then we could use:
|
||||
</p>
|
||||
<pre class="programlisting"><span class="preprocessor">#include</span> <span class="special"><</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">math</span><span class="special">/</span><span class="identifier">distributions</span><span class="special">/</span><span class="identifier">normal</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">></span>
|
||||
<span class="keyword">using</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">math</span><span class="special">::</span><span class="identifier">normal_distribution</span><span class="special">;</span>
|
||||
|
||||
<span class="keyword">using</span> <span class="keyword">namespace</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">math</span><span class="special">::</span><span class="identifier">policies</span><span class="special">;</span>
|
||||
|
||||
<span class="comment">// Define a policy:</span>
|
||||
<span class="keyword">typedef</span> <span class="identifier">policy</span><span class="special"><</span>
|
||||
<span class="identifier">promote_float</span><span class="special"><</span><span class="keyword">false</span><span class="special">></span>
|
||||
<span class="special">></span> <span class="identifier">my_policy</span><span class="special">;</span>
|
||||
|
||||
<span class="comment">// Define the new normal distribution using my_policy:</span>
|
||||
<span class="keyword">typedef</span> <span class="identifier">normal_distribution</span><span class="special"><</span><span class="keyword">float</span><span class="special">,</span> <span class="identifier">my_policy</span><span class="special">></span> <span class="identifier">my_norm</span><span class="special">;</span>
|
||||
|
||||
<span class="comment">// Get a quantile:</span>
|
||||
<span class="keyword">float</span> <span class="identifier">q</span> <span class="special">=</span> <span class="identifier">quantile</span><span class="special">(</span><span class="identifier">my_norm</span><span class="special">(),</span> <span class="number">0.05f</span><span class="special">);</span>
|
||||
</pre>
|
||||
</div>
|
||||
<table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr>
|
||||
<td align="left"></td>
|
||||
<td align="right"><div class="copyright-footer">Copyright © 2006-2010, 2012-2014 Nikhar Agrawal,
|
||||
Anton Bikineev, Paul A. Bristow, Marco Guazzone, Christopher Kormanyos, Hubert
|
||||
Holin, Bruno Lalande, John Maddock, Jeremy Murphy, Johan Råde, Gautam Sewani,
|
||||
Benjamin Sobotta, Thijs van den Berg, Daryle Walker and Xiaogang Zhang<p>
|
||||
Distributed under the Boost Software License, Version 1.0. (See accompanying
|
||||
file LICENSE_1_0.txt or copy at <a href="http://www.boost.org/LICENSE_1_0.txt" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>)
|
||||
</p>
|
||||
</div></td>
|
||||
</tr></table>
|
||||
<hr>
|
||||
<div class="spirit-nav">
|
||||
<a accesskey="p" href="error_handling_policies.html"><img src="../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../pol_ref.html"><img src="../../../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../../index.html"><img src="../../../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="assert_undefined.html"><img src="../../../../../../doc/src/images/next.png" alt="Next"></a>
|
||||
</div>
|
||||
</body>
|
||||
</html>
|
||||
@@ -0,0 +1,67 @@
|
||||
<html>
|
||||
<head>
|
||||
<meta http-equiv="Content-Type" content="text/html; charset=US-ASCII">
|
||||
<title>Iteration Limits Policies</title>
|
||||
<link rel="stylesheet" href="../../math.css" type="text/css">
|
||||
<meta name="generator" content="DocBook XSL Stylesheets V1.79.1">
|
||||
<link rel="home" href="../../index.html" title="Math Toolkit 2.5.1">
|
||||
<link rel="up" href="../pol_ref.html" title="Policy Reference">
|
||||
<link rel="prev" href="precision_pol.html" title="Precision Policies">
|
||||
<link rel="next" href="policy_defaults.html" title="Using Macros to Change the Policy Defaults">
|
||||
</head>
|
||||
<body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF">
|
||||
<table cellpadding="2" width="100%"><tr>
|
||||
<td valign="top"><img alt="Boost C++ Libraries" width="277" height="86" src="../../../../../../boost.png"></td>
|
||||
<td align="center"><a href="../../../../../../index.html">Home</a></td>
|
||||
<td align="center"><a href="../../../../../../libs/libraries.htm">Libraries</a></td>
|
||||
<td align="center"><a href="http://www.boost.org/users/people.html">People</a></td>
|
||||
<td align="center"><a href="http://www.boost.org/users/faq.html">FAQ</a></td>
|
||||
<td align="center"><a href="../../../../../../more/index.htm">More</a></td>
|
||||
</tr></table>
|
||||
<hr>
|
||||
<div class="spirit-nav">
|
||||
<a accesskey="p" href="precision_pol.html"><img src="../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../pol_ref.html"><img src="../../../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../../index.html"><img src="../../../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="policy_defaults.html"><img src="../../../../../../doc/src/images/next.png" alt="Next"></a>
|
||||
</div>
|
||||
<div class="section">
|
||||
<div class="titlepage"><div><div><h3 class="title">
|
||||
<a name="math_toolkit.pol_ref.iteration_pol"></a><a class="link" href="iteration_pol.html" title="Iteration Limits Policies">Iteration Limits
|
||||
Policies</a>
|
||||
</h3></div></div></div>
|
||||
<p>
|
||||
There are two policies that effect the iterative algorithms used to implement
|
||||
the special functions in this library:
|
||||
</p>
|
||||
<pre class="programlisting"><span class="keyword">template</span> <span class="special"><</span><span class="keyword">unsigned</span> <span class="keyword">long</span> <span class="identifier">limit</span> <span class="special">=</span> <span class="identifier">BOOST_MATH_MAX_SERIES_ITERATION_POLICY</span><span class="special">></span>
|
||||
<span class="keyword">class</span> <span class="identifier">max_series_iterations</span><span class="special">;</span>
|
||||
|
||||
<span class="keyword">template</span> <span class="special"><</span><span class="keyword">unsigned</span> <span class="keyword">long</span> <span class="identifier">limit</span> <span class="special">=</span> <span class="identifier">BOOST_MATH_MAX_ROOT_ITERATION_POLICY</span><span class="special">></span>
|
||||
<span class="keyword">class</span> <span class="identifier">max_root_iterations</span><span class="special">;</span>
|
||||
</pre>
|
||||
<p>
|
||||
The class <code class="computeroutput"><span class="identifier">max_series_iterations</span></code>
|
||||
determines the maximum number of iterations permitted in a series evaluation,
|
||||
before the special function gives up and returns the result of <a class="link" href="../error_handling.html#math_toolkit.error_handling.evaluation_error">evaluation_error</a>.
|
||||
</p>
|
||||
<p>
|
||||
The class <code class="computeroutput"><span class="identifier">max_root_iterations</span></code>
|
||||
determines the maximum number of iterations permitted in a root-finding algorithm
|
||||
before the special function gives up and returns the result of <a class="link" href="../error_handling.html#math_toolkit.error_handling.evaluation_error">evaluation_error</a>.
|
||||
</p>
|
||||
</div>
|
||||
<table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr>
|
||||
<td align="left"></td>
|
||||
<td align="right"><div class="copyright-footer">Copyright © 2006-2010, 2012-2014 Nikhar Agrawal,
|
||||
Anton Bikineev, Paul A. Bristow, Marco Guazzone, Christopher Kormanyos, Hubert
|
||||
Holin, Bruno Lalande, John Maddock, Jeremy Murphy, Johan Råde, Gautam Sewani,
|
||||
Benjamin Sobotta, Thijs van den Berg, Daryle Walker and Xiaogang Zhang<p>
|
||||
Distributed under the Boost Software License, Version 1.0. (See accompanying
|
||||
file LICENSE_1_0.txt or copy at <a href="http://www.boost.org/LICENSE_1_0.txt" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>)
|
||||
</p>
|
||||
</div></td>
|
||||
</tr></table>
|
||||
<hr>
|
||||
<div class="spirit-nav">
|
||||
<a accesskey="p" href="precision_pol.html"><img src="../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../pol_ref.html"><img src="../../../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../../index.html"><img src="../../../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="policy_defaults.html"><img src="../../../../../../doc/src/images/next.png" alt="Next"></a>
|
||||
</div>
|
||||
</body>
|
||||
</html>
|
||||
@@ -0,0 +1,157 @@
|
||||
<html>
|
||||
<head>
|
||||
<meta http-equiv="Content-Type" content="text/html; charset=US-ASCII">
|
||||
<title>Setting Polices at Namespace Scope</title>
|
||||
<link rel="stylesheet" href="../../math.css" type="text/css">
|
||||
<meta name="generator" content="DocBook XSL Stylesheets V1.79.1">
|
||||
<link rel="home" href="../../index.html" title="Math Toolkit 2.5.1">
|
||||
<link rel="up" href="../pol_ref.html" title="Policy Reference">
|
||||
<link rel="prev" href="policy_defaults.html" title="Using Macros to Change the Policy Defaults">
|
||||
<link rel="next" href="pol_ref_ref.html" title="Policy Class Reference">
|
||||
</head>
|
||||
<body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF">
|
||||
<table cellpadding="2" width="100%"><tr>
|
||||
<td valign="top"><img alt="Boost C++ Libraries" width="277" height="86" src="../../../../../../boost.png"></td>
|
||||
<td align="center"><a href="../../../../../../index.html">Home</a></td>
|
||||
<td align="center"><a href="../../../../../../libs/libraries.htm">Libraries</a></td>
|
||||
<td align="center"><a href="http://www.boost.org/users/people.html">People</a></td>
|
||||
<td align="center"><a href="http://www.boost.org/users/faq.html">FAQ</a></td>
|
||||
<td align="center"><a href="../../../../../../more/index.htm">More</a></td>
|
||||
</tr></table>
|
||||
<hr>
|
||||
<div class="spirit-nav">
|
||||
<a accesskey="p" href="policy_defaults.html"><img src="../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../pol_ref.html"><img src="../../../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../../index.html"><img src="../../../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="pol_ref_ref.html"><img src="../../../../../../doc/src/images/next.png" alt="Next"></a>
|
||||
</div>
|
||||
<div class="section">
|
||||
<div class="titlepage"><div><div><h3 class="title">
|
||||
<a name="math_toolkit.pol_ref.namespace_pol"></a><a class="link" href="namespace_pol.html" title="Setting Polices at Namespace Scope">Setting Polices at
|
||||
Namespace Scope</a>
|
||||
</h3></div></div></div>
|
||||
<p>
|
||||
Sometimes what you really want to do is bring all the special functions,
|
||||
or all the distributions into a specific namespace-scope, along with a specific
|
||||
policy to use with them. There are two macros defined to assist with that:
|
||||
</p>
|
||||
<pre class="programlisting"><span class="identifier">BOOST_MATH_DECLARE_SPECIAL_FUNCTIONS</span><span class="special">(</span><span class="identifier">Policy</span><span class="special">)</span>
|
||||
</pre>
|
||||
<p>
|
||||
and:
|
||||
</p>
|
||||
<pre class="programlisting"><span class="identifier">BOOST_MATH_DECLARE_DISTRIBUTIONS</span><span class="special">(</span><span class="identifier">Type</span><span class="special">,</span> <span class="identifier">Policy</span><span class="special">)</span>
|
||||
</pre>
|
||||
<p>
|
||||
You can use either of these macros after including any special function or
|
||||
distribution header. For example:
|
||||
</p>
|
||||
<pre class="programlisting"><span class="preprocessor">#include</span> <span class="special"><</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">math</span><span class="special">/</span><span class="identifier">special_functions</span><span class="special">/</span><span class="identifier">gamma</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">></span>
|
||||
<span class="comment">//using boost::math::tgamma;</span>
|
||||
<span class="comment">// Need not declare using boost::math::tgamma here,</span>
|
||||
<span class="comment">// because will define tgamma in myspace using macro below.</span>
|
||||
|
||||
<span class="keyword">namespace</span> <span class="identifier">myspace</span>
|
||||
<span class="special">{</span>
|
||||
<span class="keyword">using</span> <span class="keyword">namespace</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">math</span><span class="special">::</span><span class="identifier">policies</span><span class="special">;</span>
|
||||
|
||||
<span class="comment">// Define a policy that does not throw on overflow:</span>
|
||||
<span class="keyword">typedef</span> <span class="identifier">policy</span><span class="special"><</span><span class="identifier">overflow_error</span><span class="special"><</span><span class="identifier">errno_on_error</span><span class="special">></span> <span class="special">></span> <span class="identifier">my_policy</span><span class="special">;</span>
|
||||
|
||||
<span class="comment">// Define the special functions in this scope to use the policy: </span>
|
||||
<span class="identifier">BOOST_MATH_DECLARE_SPECIAL_FUNCTIONS</span><span class="special">(</span><span class="identifier">my_policy</span><span class="special">)</span>
|
||||
<span class="special">}</span>
|
||||
|
||||
<span class="comment">// Now we can use myspace::tgamma etc.</span>
|
||||
<span class="comment">// They will automatically use "my_policy":</span>
|
||||
<span class="comment">//</span>
|
||||
<span class="keyword">double</span> <span class="identifier">t</span> <span class="special">=</span> <span class="identifier">myspace</span><span class="special">::</span><span class="identifier">tgamma</span><span class="special">(</span><span class="number">30.0</span><span class="special">);</span> <span class="comment">// Will *not* throw on overflow,</span>
|
||||
<span class="comment">// despite the large value of factorial 30 = 265252859812191058636308480000000</span>
|
||||
<span class="comment">// unlike default policy boost::math::tgamma;</span>
|
||||
</pre>
|
||||
<p>
|
||||
In this example, using BOOST_MATH_DECLARE_SPECIAL_FUNCTIONS results in a
|
||||
set of thin inline forwarding functions being defined:
|
||||
</p>
|
||||
<pre class="programlisting"><span class="keyword">template</span> <span class="special"><</span><span class="keyword">class</span> <span class="identifier">T</span><span class="special">></span>
|
||||
<span class="keyword">inline</span> <span class="identifier">T</span> <span class="identifier">tgamma</span><span class="special">(</span><span class="identifier">T</span> <span class="identifier">a</span><span class="special">){</span> <span class="keyword">return</span> <span class="special">::</span><span class="identifier">boost</span><span class="special">::</span><span class="identifier">math</span><span class="special">::</span><span class="identifier">tgamma</span><span class="special">(</span><span class="identifier">a</span><span class="special">,</span> <span class="identifier">mypolicy</span><span class="special">());</span> <span class="special">}</span>
|
||||
|
||||
<span class="keyword">template</span> <span class="special"><</span><span class="keyword">class</span> <span class="identifier">T</span><span class="special">></span>
|
||||
<span class="keyword">inline</span> <span class="identifier">T</span> <span class="identifier">lgamma</span><span class="special">(</span><span class="identifier">T</span> <span class="identifier">a</span><span class="special">)</span> <span class="special">(</span> <span class="keyword">return</span> <span class="special">::</span><span class="identifier">boost</span><span class="special">::</span><span class="identifier">math</span><span class="special">::</span><span class="identifier">lgamma</span><span class="special">(</span><span class="identifier">a</span><span class="special">,</span> <span class="identifier">mypolicy</span><span class="special">());</span> <span class="special">}</span>
|
||||
</pre>
|
||||
<p>
|
||||
and so on. Note that while a forwarding function is defined for all the special
|
||||
functions, however, unless you include the specific header for the special
|
||||
function you use (or boost/math/special_functions.hpp to include everything),
|
||||
you will get linker errors from functions that are forward declared, but
|
||||
not defined.
|
||||
</p>
|
||||
<p>
|
||||
We can do the same thing with the distributions, but this time we need to
|
||||
specify the floating-point type to use:
|
||||
</p>
|
||||
<pre class="programlisting"><span class="preprocessor">#include</span> <span class="special"><</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">math</span><span class="special">/</span><span class="identifier">distributions</span><span class="special">/</span><span class="identifier">cauchy</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">></span>
|
||||
|
||||
<span class="keyword">namespace</span> <span class="identifier">myspace</span>
|
||||
<span class="special">{</span> <span class="comment">// using namespace boost::math::policies; // May be convenient in myspace.</span>
|
||||
|
||||
<span class="comment">// Define a policy called my_policy to use.</span>
|
||||
<span class="keyword">using</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">math</span><span class="special">::</span><span class="identifier">policies</span><span class="special">::</span><span class="identifier">policy</span><span class="special">;</span>
|
||||
|
||||
<span class="comment">// In this case we want all the distribution accessor functions to compile,</span>
|
||||
<span class="comment">// even if they are mathematically undefined, so</span>
|
||||
<span class="comment">// make the policy assert_undefined.</span>
|
||||
<span class="keyword">using</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">math</span><span class="special">::</span><span class="identifier">policies</span><span class="special">::</span><span class="identifier">assert_undefined</span><span class="special">;</span>
|
||||
|
||||
<span class="keyword">typedef</span> <span class="identifier">policy</span><span class="special"><</span><span class="identifier">assert_undefined</span><span class="special"><</span><span class="keyword">false</span><span class="special">></span> <span class="special">></span> <span class="identifier">my_policy</span><span class="special">;</span>
|
||||
|
||||
<span class="comment">// Finally apply this policy to type double.</span>
|
||||
<span class="identifier">BOOST_MATH_DECLARE_DISTRIBUTIONS</span><span class="special">(</span><span class="keyword">double</span><span class="special">,</span> <span class="identifier">my_policy</span><span class="special">)</span>
|
||||
<span class="special">}</span> <span class="comment">// namespace myspace</span>
|
||||
|
||||
<span class="comment">// Now we can use myspace::cauchy etc, which will use policy</span>
|
||||
<span class="comment">// myspace::mypolicy:</span>
|
||||
<span class="comment">//</span>
|
||||
<span class="comment">// This compiles but throws a domain error exception at runtime.</span>
|
||||
<span class="comment">// Caution! If you omit the try'n'catch blocks, </span>
|
||||
<span class="comment">// it will just silently terminate, giving no clues as to why! </span>
|
||||
<span class="comment">// So try'n'catch blocks are very strongly recommended.</span>
|
||||
|
||||
<span class="keyword">void</span> <span class="identifier">test_cauchy</span><span class="special">()</span>
|
||||
<span class="special">{</span>
|
||||
<span class="keyword">try</span>
|
||||
<span class="special">{</span>
|
||||
<span class="keyword">double</span> <span class="identifier">d</span> <span class="special">=</span> <span class="identifier">mean</span><span class="special">(</span><span class="identifier">myspace</span><span class="special">::</span><span class="identifier">cauchy</span><span class="special">());</span> <span class="comment">// Cauchy does not have a mean!</span>
|
||||
<span class="special">}</span>
|
||||
<span class="keyword">catch</span><span class="special">(</span><span class="keyword">const</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">domain_error</span><span class="special">&</span> <span class="identifier">e</span><span class="special">)</span>
|
||||
<span class="special">{</span>
|
||||
<span class="identifier">cout</span> <span class="special"><<</span> <span class="identifier">e</span><span class="special">.</span><span class="identifier">what</span><span class="special">()</span> <span class="special"><<</span> <span class="identifier">endl</span><span class="special">;</span>
|
||||
<span class="special">}</span>
|
||||
<span class="special">}</span>
|
||||
</pre>
|
||||
<p>
|
||||
In this example the result of BOOST_MATH_DECLARE_DISTRIBUTIONS is to declare
|
||||
a typedef for each distribution like this:
|
||||
</p>
|
||||
<pre class="programlisting"><span class="keyword">typedef</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">math</span><span class="special">::</span><span class="identifier">cauchy_distribution</span><span class="special"><</span><span class="keyword">double</span><span class="special">,</span> <span class="identifier">my_policy</span><span class="special">></span> <span class="identifier">cauchy</span><span class="special">;</span>
|
||||
<span class="identifier">tyepdef</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">math</span><span class="special">::</span><span class="identifier">gamma_distribution</span><span class="special"><</span><span class="keyword">double</span><span class="special">,</span> <span class="identifier">my_policy</span><span class="special">></span> <span class="identifier">gamma</span><span class="special">;</span>
|
||||
</pre>
|
||||
<p>
|
||||
and so on. The name given to each typedef is the name of the distribution
|
||||
with the "_distribution" suffix removed.
|
||||
</p>
|
||||
</div>
|
||||
<table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr>
|
||||
<td align="left"></td>
|
||||
<td align="right"><div class="copyright-footer">Copyright © 2006-2010, 2012-2014 Nikhar Agrawal,
|
||||
Anton Bikineev, Paul A. Bristow, Marco Guazzone, Christopher Kormanyos, Hubert
|
||||
Holin, Bruno Lalande, John Maddock, Jeremy Murphy, Johan Råde, Gautam Sewani,
|
||||
Benjamin Sobotta, Thijs van den Berg, Daryle Walker and Xiaogang Zhang<p>
|
||||
Distributed under the Boost Software License, Version 1.0. (See accompanying
|
||||
file LICENSE_1_0.txt or copy at <a href="http://www.boost.org/LICENSE_1_0.txt" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>)
|
||||
</p>
|
||||
</div></td>
|
||||
</tr></table>
|
||||
<hr>
|
||||
<div class="spirit-nav">
|
||||
<a accesskey="p" href="policy_defaults.html"><img src="../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../pol_ref.html"><img src="../../../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../../index.html"><img src="../../../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="pol_ref_ref.html"><img src="../../../../../../doc/src/images/next.png" alt="Next"></a>
|
||||
</div>
|
||||
</body>
|
||||
</html>
|
||||
@@ -0,0 +1,258 @@
|
||||
<html>
|
||||
<head>
|
||||
<meta http-equiv="Content-Type" content="text/html; charset=US-ASCII">
|
||||
<title>Policy Class Reference</title>
|
||||
<link rel="stylesheet" href="../../math.css" type="text/css">
|
||||
<meta name="generator" content="DocBook XSL Stylesheets V1.79.1">
|
||||
<link rel="home" href="../../index.html" title="Math Toolkit 2.5.1">
|
||||
<link rel="up" href="../pol_ref.html" title="Policy Reference">
|
||||
<link rel="prev" href="namespace_pol.html" title="Setting Polices at Namespace Scope">
|
||||
<link rel="next" href="../../perf.html" title="Chapter 16. Performance">
|
||||
</head>
|
||||
<body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF">
|
||||
<table cellpadding="2" width="100%"><tr>
|
||||
<td valign="top"><img alt="Boost C++ Libraries" width="277" height="86" src="../../../../../../boost.png"></td>
|
||||
<td align="center"><a href="../../../../../../index.html">Home</a></td>
|
||||
<td align="center"><a href="../../../../../../libs/libraries.htm">Libraries</a></td>
|
||||
<td align="center"><a href="http://www.boost.org/users/people.html">People</a></td>
|
||||
<td align="center"><a href="http://www.boost.org/users/faq.html">FAQ</a></td>
|
||||
<td align="center"><a href="../../../../../../more/index.htm">More</a></td>
|
||||
</tr></table>
|
||||
<hr>
|
||||
<div class="spirit-nav">
|
||||
<a accesskey="p" href="namespace_pol.html"><img src="../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../pol_ref.html"><img src="../../../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../../index.html"><img src="../../../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="../../perf.html"><img src="../../../../../../doc/src/images/next.png" alt="Next"></a>
|
||||
</div>
|
||||
<div class="section">
|
||||
<div class="titlepage"><div><div><h3 class="title">
|
||||
<a name="math_toolkit.pol_ref.pol_ref_ref"></a><a class="link" href="pol_ref_ref.html" title="Policy Class Reference">Policy Class Reference</a>
|
||||
</h3></div></div></div>
|
||||
<p>
|
||||
There's very little to say here, the <code class="computeroutput"><span class="identifier">policy</span></code>
|
||||
class is just a rag-bag compile-time container for a collection of policies:
|
||||
</p>
|
||||
<pre class="programlisting"><span class="preprocessor">#include</span> <span class="special"><</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">math</span><span class="special">/</span><span class="identifier">policies</span><span class="special">/</span><span class="identifier">policy</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">></span></pre>
|
||||
<pre class="programlisting"><span class="keyword">namespace</span> <span class="identifier">boost</span><span class="special">{</span>
|
||||
<span class="keyword">namespace</span> <span class="identifier">math</span><span class="special">{</span>
|
||||
<span class="keyword">namespace</span> <span class="identifier">policies</span>
|
||||
|
||||
<span class="keyword">template</span> <span class="special"><</span><span class="keyword">class</span> <span class="identifier">A1</span> <span class="special">=</span> <span class="identifier">default_policy</span><span class="special">,</span>
|
||||
<span class="keyword">class</span> <span class="identifier">A2</span> <span class="special">=</span> <span class="identifier">default_policy</span><span class="special">,</span>
|
||||
<span class="keyword">class</span> <span class="identifier">A3</span> <span class="special">=</span> <span class="identifier">default_policy</span><span class="special">,</span>
|
||||
<span class="keyword">class</span> <span class="identifier">A4</span> <span class="special">=</span> <span class="identifier">default_policy</span><span class="special">,</span>
|
||||
<span class="keyword">class</span> <span class="identifier">A5</span> <span class="special">=</span> <span class="identifier">default_policy</span><span class="special">,</span>
|
||||
<span class="keyword">class</span> <span class="identifier">A6</span> <span class="special">=</span> <span class="identifier">default_policy</span><span class="special">,</span>
|
||||
<span class="keyword">class</span> <span class="identifier">A7</span> <span class="special">=</span> <span class="identifier">default_policy</span><span class="special">,</span>
|
||||
<span class="keyword">class</span> <span class="identifier">A8</span> <span class="special">=</span> <span class="identifier">default_policy</span><span class="special">,</span>
|
||||
<span class="keyword">class</span> <span class="identifier">A9</span> <span class="special">=</span> <span class="identifier">default_policy</span><span class="special">,</span>
|
||||
<span class="keyword">class</span> <span class="identifier">A10</span> <span class="special">=</span> <span class="identifier">default_policy</span><span class="special">,</span>
|
||||
<span class="keyword">class</span> <span class="identifier">A11</span> <span class="special">=</span> <span class="identifier">default_policy</span><span class="special">,</span>
|
||||
<span class="keyword">class</span> <span class="identifier">A12</span> <span class="special">=</span> <span class="identifier">default_policy</span><span class="special">,</span>
|
||||
<span class="keyword">class</span> <span class="identifier">A13</span> <span class="special">=</span> <span class="identifier">default_policy</span><span class="special">></span>
|
||||
<span class="keyword">struct</span> <span class="identifier">policy</span>
|
||||
<span class="special">{</span>
|
||||
<span class="keyword">public</span><span class="special">:</span>
|
||||
<span class="keyword">typedef</span> <span class="emphasis"><em>computed-from-template-arguments</em></span> <span class="identifier">domain_error_type</span><span class="special">;</span>
|
||||
<span class="keyword">typedef</span> <span class="emphasis"><em>computed-from-template-arguments</em></span> <span class="identifier">pole_error_type</span><span class="special">;</span>
|
||||
<span class="keyword">typedef</span> <span class="emphasis"><em>computed-from-template-arguments</em></span> <span class="identifier">overflow_error_type</span><span class="special">;</span>
|
||||
<span class="keyword">typedef</span> <span class="emphasis"><em>computed-from-template-arguments</em></span> <span class="identifier">underflow_error_type</span><span class="special">;</span>
|
||||
<span class="keyword">typedef</span> <span class="emphasis"><em>computed-from-template-arguments</em></span> <span class="identifier">denorm_error_type</span><span class="special">;</span>
|
||||
<span class="keyword">typedef</span> <span class="emphasis"><em>computed-from-template-arguments</em></span> <span class="identifier">rounding_error_type</span><span class="special">;</span>
|
||||
<span class="keyword">typedef</span> <span class="emphasis"><em>computed-from-template-arguments</em></span> <span class="identifier">evaluation_error_type</span><span class="special">;</span>
|
||||
<span class="keyword">typedef</span> <span class="emphasis"><em>computed-from-template-arguments</em></span> <span class="identifier">indeterminate_result_error_type</span><span class="special">;</span>
|
||||
<span class="keyword">typedef</span> <span class="emphasis"><em>computed-from-template-arguments</em></span> <span class="identifier">precision_type</span><span class="special">;</span>
|
||||
<span class="keyword">typedef</span> <span class="emphasis"><em>computed-from-template-arguments</em></span> <span class="identifier">promote_float_type</span><span class="special">;</span>
|
||||
<span class="keyword">typedef</span> <span class="emphasis"><em>computed-from-template-arguments</em></span> <span class="identifier">promote_double_type</span><span class="special">;</span>
|
||||
<span class="keyword">typedef</span> <span class="emphasis"><em>computed-from-template-arguments</em></span> <span class="identifier">discrete_quantile_type</span><span class="special">;</span>
|
||||
<span class="keyword">typedef</span> <span class="emphasis"><em>computed-from-template-arguments</em></span> <span class="identifier">assert_undefined_type</span><span class="special">;</span>
|
||||
<span class="special">};</span>
|
||||
|
||||
<span class="keyword">template</span> <span class="special"><...</span><span class="identifier">argument</span> <span class="identifier">list</span><span class="special">...></span>
|
||||
<span class="keyword">typename</span> <span class="identifier">normalise</span><span class="special"><</span><span class="identifier">policy</span><span class="special"><>,</span> <span class="identifier">A1</span><span class="special">>::</span><span class="identifier">type</span> <span class="identifier">make_policy</span><span class="special">(...</span><span class="identifier">argument</span> <span class="identifier">list</span><span class="special">..);</span>
|
||||
|
||||
<span class="keyword">template</span> <span class="special"><</span><span class="keyword">class</span> <span class="identifier">Policy</span><span class="special">,</span>
|
||||
<span class="keyword">class</span> <span class="identifier">A1</span> <span class="special">=</span> <span class="identifier">default_policy</span><span class="special">,</span>
|
||||
<span class="keyword">class</span> <span class="identifier">A2</span> <span class="special">=</span> <span class="identifier">default_policy</span><span class="special">,</span>
|
||||
<span class="keyword">class</span> <span class="identifier">A3</span> <span class="special">=</span> <span class="identifier">default_policy</span><span class="special">,</span>
|
||||
<span class="keyword">class</span> <span class="identifier">A4</span> <span class="special">=</span> <span class="identifier">default_policy</span><span class="special">,</span>
|
||||
<span class="keyword">class</span> <span class="identifier">A5</span> <span class="special">=</span> <span class="identifier">default_policy</span><span class="special">,</span>
|
||||
<span class="keyword">class</span> <span class="identifier">A6</span> <span class="special">=</span> <span class="identifier">default_policy</span><span class="special">,</span>
|
||||
<span class="keyword">class</span> <span class="identifier">A7</span> <span class="special">=</span> <span class="identifier">default_policy</span><span class="special">,</span>
|
||||
<span class="keyword">class</span> <span class="identifier">A8</span> <span class="special">=</span> <span class="identifier">default_policy</span><span class="special">,</span>
|
||||
<span class="keyword">class</span> <span class="identifier">A9</span> <span class="special">=</span> <span class="identifier">default_policy</span><span class="special">,</span>
|
||||
<span class="keyword">class</span> <span class="identifier">A10</span> <span class="special">=</span> <span class="identifier">default_policy</span><span class="special">,</span>
|
||||
<span class="keyword">class</span> <span class="identifier">A11</span> <span class="special">=</span> <span class="identifier">default_policy</span><span class="special">,</span>
|
||||
<span class="keyword">class</span> <span class="identifier">A12</span> <span class="special">=</span> <span class="identifier">default_policy</span><span class="special">,</span>
|
||||
<span class="keyword">class</span> <span class="identifier">A13</span> <span class="special">=</span> <span class="identifier">default_policy</span><span class="special">></span>
|
||||
<span class="keyword">struct</span> <span class="identifier">normalise</span>
|
||||
<span class="special">{</span>
|
||||
<span class="keyword">typedef</span> computed-from-template-arguments <span class="identifier">type</span><span class="special">;</span>
|
||||
<span class="special">};</span>
|
||||
</pre>
|
||||
<p>
|
||||
The member typedefs of class <code class="computeroutput"><span class="identifier">policy</span></code>
|
||||
are intended for internal use but are documented briefly here for the sake
|
||||
of completeness.
|
||||
</p>
|
||||
<pre class="programlisting"><span class="identifier">policy</span><span class="special"><...>::</span><span class="identifier">domain_error_type</span>
|
||||
</pre>
|
||||
<p>
|
||||
Specifies how domain errors are handled, will be an instance of <code class="computeroutput"><span class="identifier">boost</span><span class="special">::</span><span class="identifier">math</span><span class="special">::</span><span class="identifier">policies</span><span class="special">::</span><span class="identifier">domain_error</span><span class="special"><></span></code>
|
||||
with the template argument to <code class="computeroutput"><span class="identifier">domain_error</span></code>
|
||||
one of the <code class="computeroutput"><span class="identifier">error_policy_type</span></code>
|
||||
enumerated values.
|
||||
</p>
|
||||
<pre class="programlisting"><span class="identifier">policy</span><span class="special"><...>::</span><span class="identifier">pole_error_type</span>
|
||||
</pre>
|
||||
<p>
|
||||
Specifies how pole-errors are handled, will be an instance of <code class="computeroutput"><span class="identifier">boost</span><span class="special">::</span><span class="identifier">math</span><span class="special">::</span><span class="identifier">policies</span><span class="special">::</span><span class="identifier">pole_error</span><span class="special"><></span></code>
|
||||
with the template argument to <code class="computeroutput"><span class="identifier">pole_error</span></code>
|
||||
one of the <code class="computeroutput"><span class="identifier">error_policy_type</span></code>
|
||||
enumerated values.
|
||||
</p>
|
||||
<pre class="programlisting"><span class="identifier">policy</span><span class="special"><...>::</span><span class="identifier">overflow_error_type</span>
|
||||
</pre>
|
||||
<p>
|
||||
Specifies how overflow errors are handled, will be an instance of <code class="computeroutput"><span class="identifier">boost</span><span class="special">::</span><span class="identifier">math</span><span class="special">::</span><span class="identifier">policies</span><span class="special">::</span><span class="identifier">overflow_error</span><span class="special"><></span></code>
|
||||
with the template argument to <code class="computeroutput"><span class="identifier">overflow_error</span></code>
|
||||
one of the <code class="computeroutput"><span class="identifier">error_policy_type</span></code>
|
||||
enumerated values.
|
||||
</p>
|
||||
<pre class="programlisting"><span class="identifier">policy</span><span class="special"><...>::</span><span class="identifier">underflow_error_type</span>
|
||||
</pre>
|
||||
<p>
|
||||
Specifies how underflow errors are handled, will be an instance of <code class="computeroutput"><span class="identifier">boost</span><span class="special">::</span><span class="identifier">math</span><span class="special">::</span><span class="identifier">policies</span><span class="special">::</span><span class="identifier">underflow_error</span><span class="special"><></span></code>
|
||||
with the template argument to <code class="computeroutput"><span class="identifier">underflow_error</span></code>
|
||||
one of the <code class="computeroutput"><span class="identifier">error_policy_type</span></code>
|
||||
enumerated values.
|
||||
</p>
|
||||
<pre class="programlisting"><span class="identifier">policy</span><span class="special"><...>::</span><span class="identifier">denorm_error_type</span>
|
||||
</pre>
|
||||
<p>
|
||||
Specifies how denorm errors are handled, will be an instance of <code class="computeroutput"><span class="identifier">boost</span><span class="special">::</span><span class="identifier">math</span><span class="special">::</span><span class="identifier">policies</span><span class="special">::</span><span class="identifier">denorm_error</span><span class="special"><></span></code>
|
||||
with the template argument to <code class="computeroutput"><span class="identifier">denorm_error</span></code>
|
||||
one of the <code class="computeroutput"><span class="identifier">error_policy_type</span></code>
|
||||
enumerated values.
|
||||
</p>
|
||||
<pre class="programlisting"><span class="identifier">policy</span><span class="special"><...>::</span><span class="identifier">rounding_error_type</span>
|
||||
</pre>
|
||||
<p>
|
||||
Specifies how rounding errors are handled, will be an instance of <code class="computeroutput"><span class="identifier">boost</span><span class="special">::</span><span class="identifier">math</span><span class="special">::</span><span class="identifier">policies</span><span class="special">::</span><span class="identifier">rounding_error</span><span class="special"><></span></code>
|
||||
with the template argument to <code class="computeroutput"><span class="identifier">rounding_error</span></code>
|
||||
one of the <code class="computeroutput"><span class="identifier">error_policy_type</span></code>
|
||||
enumerated values.
|
||||
</p>
|
||||
<pre class="programlisting"><span class="identifier">policy</span><span class="special"><...>::</span><span class="identifier">evaluation_error_type</span>
|
||||
</pre>
|
||||
<p>
|
||||
Specifies how evaluation errors are handled, will be an instance of <code class="computeroutput"><span class="identifier">boost</span><span class="special">::</span><span class="identifier">math</span><span class="special">::</span><span class="identifier">policies</span><span class="special">::</span><span class="identifier">evaluation_error</span><span class="special"><></span></code>
|
||||
with the template argument to <code class="computeroutput"><span class="identifier">evaluation_error</span></code>
|
||||
one of the <code class="computeroutput"><span class="identifier">error_policy_type</span></code>
|
||||
enumerated values.
|
||||
</p>
|
||||
<pre class="programlisting"><span class="identifier">policy</span><span class="special"><...>::</span><span class="identifier">indeterminate_error_type</span>
|
||||
</pre>
|
||||
<p>
|
||||
Specifies how indeterminate result errors are handled, will be an instance
|
||||
of <code class="computeroutput"><span class="identifier">boost</span><span class="special">::</span><span class="identifier">math</span><span class="special">::</span><span class="identifier">policies</span><span class="special">::</span><span class="identifier">indeterminate_result_error</span><span class="special"><></span></code>
|
||||
with the template argument to <code class="computeroutput"><span class="identifier">indeterminate_result_error</span></code>
|
||||
one of the <code class="computeroutput"><span class="identifier">error_policy_type</span></code>
|
||||
enumerated values.
|
||||
</p>
|
||||
<pre class="programlisting"><span class="identifier">policy</span><span class="special"><...>::</span><span class="identifier">precision_type</span>
|
||||
</pre>
|
||||
<p>
|
||||
Specifies the internal precision to use in binary digits (uses zero to represent
|
||||
whatever the default precision is). Will be an instance of <code class="computeroutput"><span class="identifier">boost</span><span class="special">::</span><span class="identifier">math</span><span class="special">::</span><span class="identifier">policies</span><span class="special">::</span><span class="identifier">digits2</span><span class="special"><</span><span class="identifier">N</span><span class="special">></span></code> which
|
||||
in turn inherits from <code class="computeroutput"><span class="identifier">boost</span><span class="special">::</span><span class="identifier">mpl</span><span class="special">::</span><span class="identifier">int_</span><span class="special"><</span><span class="identifier">N</span><span class="special">></span></code>.
|
||||
</p>
|
||||
<pre class="programlisting"><span class="identifier">policy</span><span class="special"><...>::</span><span class="identifier">promote_float_type</span>
|
||||
</pre>
|
||||
<p>
|
||||
Specifies whether or not to promote <code class="computeroutput"><span class="keyword">float</span></code>
|
||||
arguments to <code class="computeroutput"><span class="keyword">double</span></code> precision
|
||||
internally. Will be an instance of <code class="computeroutput"><span class="identifier">boost</span><span class="special">::</span><span class="identifier">math</span><span class="special">::</span><span class="identifier">policies</span><span class="special">::</span><span class="identifier">promote_float</span><span class="special"><</span><span class="identifier">B</span><span class="special">></span></code>
|
||||
which in turn inherits from <code class="computeroutput"><span class="identifier">boost</span><span class="special">::</span><span class="identifier">mpl</span><span class="special">::</span><span class="identifier">bool_</span><span class="special"><</span><span class="identifier">B</span><span class="special">></span></code>.
|
||||
</p>
|
||||
<pre class="programlisting"><span class="identifier">policy</span><span class="special"><...>::</span><span class="identifier">promote_double_type</span>
|
||||
</pre>
|
||||
<p>
|
||||
Specifies whether or not to promote <code class="computeroutput"><span class="keyword">double</span></code>
|
||||
arguments to <code class="computeroutput"><span class="keyword">long</span> <span class="keyword">double</span></code>
|
||||
precision internally. Will be an instance of <code class="computeroutput"><span class="identifier">boost</span><span class="special">::</span><span class="identifier">math</span><span class="special">::</span><span class="identifier">policies</span><span class="special">::</span><span class="identifier">promote_float</span><span class="special"><</span><span class="identifier">B</span><span class="special">></span></code>
|
||||
which in turn inherits from <code class="computeroutput"><span class="identifier">boost</span><span class="special">::</span><span class="identifier">mpl</span><span class="special">::</span><span class="identifier">bool_</span><span class="special"><</span><span class="identifier">B</span><span class="special">></span></code>.
|
||||
</p>
|
||||
<pre class="programlisting"><span class="identifier">policy</span><span class="special"><...>::</span><span class="identifier">discrete_quantile_type</span>
|
||||
</pre>
|
||||
<p>
|
||||
Specifies how discrete quantiles are evaluated, will be an instance of <code class="computeroutput"><span class="identifier">boost</span><span class="special">::</span><span class="identifier">math</span><span class="special">::</span><span class="identifier">policies</span><span class="special">::</span><span class="identifier">discrete_quantile</span><span class="special"><></span></code>
|
||||
instantiated with one of the <code class="computeroutput"><span class="identifier">discrete_quantile_policy_type</span></code>
|
||||
enumerated type.
|
||||
</p>
|
||||
<pre class="programlisting"><span class="identifier">policy</span><span class="special"><...>::</span><span class="identifier">assert_undefined_type</span>
|
||||
</pre>
|
||||
<p>
|
||||
Specifies whether mathematically-undefined properties are asserted as compile-time
|
||||
errors, or treated as runtime errors instead. Will be an instance of <code class="computeroutput"><span class="identifier">boost</span><span class="special">::</span><span class="identifier">math</span><span class="special">::</span><span class="identifier">policies</span><span class="special">::</span><span class="identifier">assert_undefined</span><span class="special"><</span><span class="identifier">B</span><span class="special">></span></code> which
|
||||
in turn inherits from <code class="computeroutput"><span class="identifier">boost</span><span class="special">::</span><span class="identifier">math</span><span class="special">::</span><span class="identifier">mpl</span><span class="special">::</span><span class="identifier">bool_</span><span class="special"><</span><span class="identifier">B</span><span class="special">></span></code>.
|
||||
</p>
|
||||
<pre class="programlisting"><span class="keyword">template</span> <span class="special"><...</span><span class="identifier">argument</span> <span class="identifier">list</span><span class="special">...></span>
|
||||
<span class="keyword">typename</span> <span class="identifier">normalise</span><span class="special"><</span><span class="identifier">policy</span><span class="special"><>,</span> <span class="identifier">A1</span><span class="special">>::</span><span class="identifier">type</span> <span class="identifier">make_policy</span><span class="special">(...</span><span class="identifier">argument</span> <span class="identifier">list</span><span class="special">..);</span>
|
||||
</pre>
|
||||
<p>
|
||||
<code class="computeroutput"><span class="identifier">make_policy</span></code> is a helper function
|
||||
that converts a list of policies into a normalised <code class="computeroutput"><span class="identifier">policy</span></code>
|
||||
class.
|
||||
</p>
|
||||
<pre class="programlisting"><span class="keyword">template</span> <span class="special"><</span><span class="keyword">class</span> <span class="identifier">Policy</span><span class="special">,</span>
|
||||
<span class="keyword">class</span> <span class="identifier">A1</span> <span class="special">=</span> <span class="identifier">default_policy</span><span class="special">,</span>
|
||||
<span class="keyword">class</span> <span class="identifier">A2</span> <span class="special">=</span> <span class="identifier">default_policy</span><span class="special">,</span>
|
||||
<span class="keyword">class</span> <span class="identifier">A3</span> <span class="special">=</span> <span class="identifier">default_policy</span><span class="special">,</span>
|
||||
<span class="keyword">class</span> <span class="identifier">A4</span> <span class="special">=</span> <span class="identifier">default_policy</span><span class="special">,</span>
|
||||
<span class="keyword">class</span> <span class="identifier">A5</span> <span class="special">=</span> <span class="identifier">default_policy</span><span class="special">,</span>
|
||||
<span class="keyword">class</span> <span class="identifier">A6</span> <span class="special">=</span> <span class="identifier">default_policy</span><span class="special">,</span>
|
||||
<span class="keyword">class</span> <span class="identifier">A7</span> <span class="special">=</span> <span class="identifier">default_policy</span><span class="special">,</span>
|
||||
<span class="keyword">class</span> <span class="identifier">A8</span> <span class="special">=</span> <span class="identifier">default_policy</span><span class="special">,</span>
|
||||
<span class="keyword">class</span> <span class="identifier">A9</span> <span class="special">=</span> <span class="identifier">default_policy</span><span class="special">,</span>
|
||||
<span class="keyword">class</span> <span class="identifier">A10</span> <span class="special">=</span> <span class="identifier">default_policy</span><span class="special">,</span>
|
||||
<span class="keyword">class</span> <span class="identifier">A11</span> <span class="special">=</span> <span class="identifier">default_policy</span><span class="special">,</span>
|
||||
<span class="keyword">class</span> <span class="identifier">A12</span> <span class="special">=</span> <span class="identifier">default_policy</span><span class="special">,</span>
|
||||
<span class="keyword">class</span> <span class="identifier">A13</span> <span class="special">=</span> <span class="identifier">default_policy</span><span class="special">></span>
|
||||
<span class="keyword">struct</span> <span class="identifier">normalise</span>
|
||||
<span class="special">{</span>
|
||||
<span class="keyword">typedef</span> computed-from-template-arguments <span class="identifier">type</span><span class="special">;</span>
|
||||
<span class="special">};</span>
|
||||
</pre>
|
||||
<p>
|
||||
The <code class="computeroutput"><span class="identifier">normalise</span></code> class template
|
||||
converts one instantiation of the <code class="computeroutput"><span class="identifier">policy</span></code>
|
||||
class into a normalised form. This is used internally to reduce code bloat:
|
||||
so that instantiating a special function on <code class="computeroutput"><span class="identifier">policy</span><span class="special"><</span><span class="identifier">A</span><span class="special">,</span><span class="identifier">B</span><span class="special">></span></code> or
|
||||
<code class="computeroutput"><span class="identifier">policy</span><span class="special"><</span><span class="identifier">B</span><span class="special">,</span><span class="identifier">A</span><span class="special">></span></code> actually both generate the same code
|
||||
internally.
|
||||
</p>
|
||||
<p>
|
||||
Further more, <code class="computeroutput"><span class="identifier">normalise</span></code> can
|
||||
be used to combine a policy with one or more policies: for example many of
|
||||
the special functions will use this to set policies which they don't make
|
||||
use of to their default values, before forwarding to the actual implementation.
|
||||
In this way code bloat is reduced, since the actual implementation depends
|
||||
only on the policy types that they actually use.
|
||||
</p>
|
||||
</div>
|
||||
<table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr>
|
||||
<td align="left"></td>
|
||||
<td align="right"><div class="copyright-footer">Copyright © 2006-2010, 2012-2014 Nikhar Agrawal,
|
||||
Anton Bikineev, Paul A. Bristow, Marco Guazzone, Christopher Kormanyos, Hubert
|
||||
Holin, Bruno Lalande, John Maddock, Jeremy Murphy, Johan Råde, Gautam Sewani,
|
||||
Benjamin Sobotta, Thijs van den Berg, Daryle Walker and Xiaogang Zhang<p>
|
||||
Distributed under the Boost Software License, Version 1.0. (See accompanying
|
||||
file LICENSE_1_0.txt or copy at <a href="http://www.boost.org/LICENSE_1_0.txt" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>)
|
||||
</p>
|
||||
</div></td>
|
||||
</tr></table>
|
||||
<hr>
|
||||
<div class="spirit-nav">
|
||||
<a accesskey="p" href="namespace_pol.html"><img src="../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../pol_ref.html"><img src="../../../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../../index.html"><img src="../../../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="../../perf.html"><img src="../../../../../../doc/src/images/next.png" alt="Next"></a>
|
||||
</div>
|
||||
</body>
|
||||
</html>
|
||||
@@ -0,0 +1,258 @@
|
||||
<html>
|
||||
<head>
|
||||
<meta http-equiv="Content-Type" content="text/html; charset=US-ASCII">
|
||||
<title>Using Macros to Change the Policy Defaults</title>
|
||||
<link rel="stylesheet" href="../../math.css" type="text/css">
|
||||
<meta name="generator" content="DocBook XSL Stylesheets V1.79.1">
|
||||
<link rel="home" href="../../index.html" title="Math Toolkit 2.5.1">
|
||||
<link rel="up" href="../pol_ref.html" title="Policy Reference">
|
||||
<link rel="prev" href="iteration_pol.html" title="Iteration Limits Policies">
|
||||
<link rel="next" href="namespace_pol.html" title="Setting Polices at Namespace Scope">
|
||||
</head>
|
||||
<body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF">
|
||||
<table cellpadding="2" width="100%"><tr>
|
||||
<td valign="top"><img alt="Boost C++ Libraries" width="277" height="86" src="../../../../../../boost.png"></td>
|
||||
<td align="center"><a href="../../../../../../index.html">Home</a></td>
|
||||
<td align="center"><a href="../../../../../../libs/libraries.htm">Libraries</a></td>
|
||||
<td align="center"><a href="http://www.boost.org/users/people.html">People</a></td>
|
||||
<td align="center"><a href="http://www.boost.org/users/faq.html">FAQ</a></td>
|
||||
<td align="center"><a href="../../../../../../more/index.htm">More</a></td>
|
||||
</tr></table>
|
||||
<hr>
|
||||
<div class="spirit-nav">
|
||||
<a accesskey="p" href="iteration_pol.html"><img src="../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../pol_ref.html"><img src="../../../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../../index.html"><img src="../../../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="namespace_pol.html"><img src="../../../../../../doc/src/images/next.png" alt="Next"></a>
|
||||
</div>
|
||||
<div class="section">
|
||||
<div class="titlepage"><div><div><h3 class="title">
|
||||
<a name="math_toolkit.pol_ref.policy_defaults"></a><a class="link" href="policy_defaults.html" title="Using Macros to Change the Policy Defaults">Using Macros to
|
||||
Change the Policy Defaults</a>
|
||||
</h3></div></div></div>
|
||||
<p>
|
||||
You can use the various macros below to change any (or all) of the policies.
|
||||
</p>
|
||||
<p>
|
||||
You can make a local change by placing a macro definition <span class="bold"><strong>before</strong></span>
|
||||
a function or distribution #include.
|
||||
</p>
|
||||
<div class="caution"><table border="0" summary="Caution">
|
||||
<tr>
|
||||
<td rowspan="2" align="center" valign="top" width="25"><img alt="[Caution]" src="../../../../../../doc/src/images/caution.png"></td>
|
||||
<th align="left">Caution</th>
|
||||
</tr>
|
||||
<tr><td align="left" valign="top"><p>
|
||||
There is a danger of One-Definition-Rule violations if you add ad-hoc macros
|
||||
to more than one source files: these must be set the same in <span class="bold"><strong>every translation unit</strong></span>.
|
||||
</p></td></tr>
|
||||
</table></div>
|
||||
<div class="caution"><table border="0" summary="Caution">
|
||||
<tr>
|
||||
<td rowspan="2" align="center" valign="top" width="25"><img alt="[Caution]" src="../../../../../../doc/src/images/caution.png"></td>
|
||||
<th align="left">Caution</th>
|
||||
</tr>
|
||||
<tr><td align="left" valign="top"><p>
|
||||
If you place it after the #include it will have no effect, (and it will
|
||||
affect only any other following #includes). This is probably not what you
|
||||
intend!
|
||||
</p></td></tr>
|
||||
</table></div>
|
||||
<p>
|
||||
If you want to alter the defaults for any or all of the policies for <span class="bold"><strong>all</strong></span> functions and distributions, installation-wide,
|
||||
then you can do so by defining various macros in <a href="../../../../../../boost/math/tools/user.hpp" target="_top">boost/math/tools/user.hpp</a>.
|
||||
</p>
|
||||
<h6>
|
||||
<a name="math_toolkit.pol_ref.policy_defaults.h0"></a>
|
||||
<span class="phrase"><a name="math_toolkit.pol_ref.policy_defaults.boost_math_domain_error_policy"></a></span><a class="link" href="policy_defaults.html#math_toolkit.pol_ref.policy_defaults.boost_math_domain_error_policy">BOOST_MATH_DOMAIN_ERROR_POLICY</a>
|
||||
</h6>
|
||||
<p>
|
||||
Defines what happens when a domain error occurs, if not defined then defaults
|
||||
to <code class="computeroutput"><span class="identifier">throw_on_error</span></code>, but can
|
||||
be set to any of the enumerated actions for error handing: <code class="computeroutput"><span class="identifier">throw_on_error</span></code>, <code class="computeroutput"><span class="identifier">errno_on_error</span></code>,
|
||||
<code class="computeroutput"><span class="identifier">ignore_error</span></code> or <code class="computeroutput"><span class="identifier">user_error</span></code>.
|
||||
</p>
|
||||
<h6>
|
||||
<a name="math_toolkit.pol_ref.policy_defaults.h1"></a>
|
||||
<span class="phrase"><a name="math_toolkit.pol_ref.policy_defaults.boost_math_pole_error_policy"></a></span><a class="link" href="policy_defaults.html#math_toolkit.pol_ref.policy_defaults.boost_math_pole_error_policy">BOOST_MATH_POLE_ERROR_POLICY</a>
|
||||
</h6>
|
||||
<p>
|
||||
Defines what happens when a pole error occurs, if not defined then defaults
|
||||
to <code class="computeroutput"><span class="identifier">throw_on_error</span></code>, but can
|
||||
be set to any of the enumerated actions for error handing: <code class="computeroutput"><span class="identifier">throw_on_error</span></code>, <code class="computeroutput"><span class="identifier">errno_on_error</span></code>,
|
||||
<code class="computeroutput"><span class="identifier">ignore_error</span></code> or <code class="computeroutput"><span class="identifier">user_error</span></code>.
|
||||
</p>
|
||||
<h6>
|
||||
<a name="math_toolkit.pol_ref.policy_defaults.h2"></a>
|
||||
<span class="phrase"><a name="math_toolkit.pol_ref.policy_defaults.boost_math_overflow_error_policy"></a></span><a class="link" href="policy_defaults.html#math_toolkit.pol_ref.policy_defaults.boost_math_overflow_error_policy">BOOST_MATH_OVERFLOW_ERROR_POLICY</a>
|
||||
</h6>
|
||||
<p>
|
||||
Defines what happens when an overflow error occurs, if not defined then defaults
|
||||
to <code class="computeroutput"><span class="identifier">throw_on_error</span></code>, but can
|
||||
be set to any of the enumerated actions for error handing: <code class="computeroutput"><span class="identifier">throw_on_error</span></code>, <code class="computeroutput"><span class="identifier">errno_on_error</span></code>,
|
||||
<code class="computeroutput"><span class="identifier">ignore_error</span></code> or <code class="computeroutput"><span class="identifier">user_error</span></code>.
|
||||
</p>
|
||||
<h6>
|
||||
<a name="math_toolkit.pol_ref.policy_defaults.h3"></a>
|
||||
<span class="phrase"><a name="math_toolkit.pol_ref.policy_defaults.boost_math_rounding_error_policy"></a></span><a class="link" href="policy_defaults.html#math_toolkit.pol_ref.policy_defaults.boost_math_rounding_error_policy">BOOST_MATH_ROUNDING_ERROR_POLICY</a>
|
||||
</h6>
|
||||
<p>
|
||||
Defines what happens when a rounding error occurs, if not defined then defaults
|
||||
to <code class="computeroutput"><span class="identifier">throw_on_error</span></code>, but can
|
||||
be set to any of the enumerated actions for error handing: <code class="computeroutput"><span class="identifier">throw_on_error</span></code>, <code class="computeroutput"><span class="identifier">errno_on_error</span></code>,
|
||||
<code class="computeroutput"><span class="identifier">ignore_error</span></code> or <code class="computeroutput"><span class="identifier">user_error</span></code>.
|
||||
</p>
|
||||
<h6>
|
||||
<a name="math_toolkit.pol_ref.policy_defaults.h4"></a>
|
||||
<span class="phrase"><a name="math_toolkit.pol_ref.policy_defaults.boost_math_evaluation_error_poli"></a></span><a class="link" href="policy_defaults.html#math_toolkit.pol_ref.policy_defaults.boost_math_evaluation_error_poli">BOOST_MATH_EVALUATION_ERROR_POLICY</a>
|
||||
</h6>
|
||||
<p>
|
||||
Defines what happens when an internal evaluation error occurs, if not defined
|
||||
then defaults to <code class="computeroutput"><span class="identifier">throw_on_error</span></code>,
|
||||
but can be set to any of the enumerated actions for error handing: <code class="computeroutput"><span class="identifier">throw_on_error</span></code>, <code class="computeroutput"><span class="identifier">errno_on_error</span></code>,
|
||||
<code class="computeroutput"><span class="identifier">ignore_error</span></code> or <code class="computeroutput"><span class="identifier">user_error</span></code>.
|
||||
</p>
|
||||
<h6>
|
||||
<a name="math_toolkit.pol_ref.policy_defaults.h5"></a>
|
||||
<span class="phrase"><a name="math_toolkit.pol_ref.policy_defaults.boost_math_underflow_error_polic"></a></span><a class="link" href="policy_defaults.html#math_toolkit.pol_ref.policy_defaults.boost_math_underflow_error_polic">BOOST_MATH_UNDERFLOW_ERROR_POLICY</a>
|
||||
</h6>
|
||||
<p>
|
||||
Defines what happens when an overflow error occurs, if not defined then defaults
|
||||
to <code class="computeroutput"><span class="identifier">ignore_error</span></code>, but can
|
||||
be set to any of the enumerated actions for error handing: <code class="computeroutput"><span class="identifier">throw_on_error</span></code>, <code class="computeroutput"><span class="identifier">errno_on_error</span></code>,
|
||||
<code class="computeroutput"><span class="identifier">ignore_error</span></code> or <code class="computeroutput"><span class="identifier">user_error</span></code>.
|
||||
</p>
|
||||
<h6>
|
||||
<a name="math_toolkit.pol_ref.policy_defaults.h6"></a>
|
||||
<span class="phrase"><a name="math_toolkit.pol_ref.policy_defaults.boost_math_denorm_error_policy"></a></span><a class="link" href="policy_defaults.html#math_toolkit.pol_ref.policy_defaults.boost_math_denorm_error_policy">BOOST_MATH_DENORM_ERROR_POLICY</a>
|
||||
</h6>
|
||||
<p>
|
||||
Defines what happens when a denormalisation error occurs, if not defined
|
||||
then defaults to <code class="computeroutput"><span class="identifier">ignore_error</span></code>,
|
||||
but can be set to any of the enumerated actions for error handing: <code class="computeroutput"><span class="identifier">throw_on_error</span></code>, <code class="computeroutput"><span class="identifier">errno_on_error</span></code>,
|
||||
<code class="computeroutput"><span class="identifier">ignore_error</span></code> or <code class="computeroutput"><span class="identifier">user_error</span></code>.
|
||||
</p>
|
||||
<h6>
|
||||
<a name="math_toolkit.pol_ref.policy_defaults.h7"></a>
|
||||
<span class="phrase"><a name="math_toolkit.pol_ref.policy_defaults.boost_math_indeterminate_result_"></a></span><a class="link" href="policy_defaults.html#math_toolkit.pol_ref.policy_defaults.boost_math_indeterminate_result_">BOOST_MATH_INDETERMINATE_RESULT_ERROR_POLICY</a>
|
||||
</h6>
|
||||
<p>
|
||||
Defines what happens when the result is indeterminate, but where there is
|
||||
none the less a convention for the result. If not defined then defaults to
|
||||
<code class="computeroutput"><span class="identifier">ignore_error</span></code>, but can be
|
||||
set to any of the enumerated actions for error handing: <code class="computeroutput"><span class="identifier">throw_on_error</span></code>,
|
||||
<code class="computeroutput"><span class="identifier">errno_on_error</span></code>, <code class="computeroutput"><span class="identifier">ignore_error</span></code> or <code class="computeroutput"><span class="identifier">user_error</span></code>.
|
||||
</p>
|
||||
<h6>
|
||||
<a name="math_toolkit.pol_ref.policy_defaults.h8"></a>
|
||||
<span class="phrase"><a name="math_toolkit.pol_ref.policy_defaults.boost_math_digits10_policy"></a></span><a class="link" href="policy_defaults.html#math_toolkit.pol_ref.policy_defaults.boost_math_digits10_policy">BOOST_MATH_DIGITS10_POLICY</a>
|
||||
</h6>
|
||||
<p>
|
||||
Defines how many decimal digits to use in internal computations: defaults
|
||||
to <code class="computeroutput"><span class="number">0</span></code> - meaning use all available
|
||||
digits - but can be set to some other decimal value. Since setting this is
|
||||
likely to have a substantial impact on accuracy, it's not generally recommended
|
||||
that you change this from the default.
|
||||
</p>
|
||||
<h6>
|
||||
<a name="math_toolkit.pol_ref.policy_defaults.h9"></a>
|
||||
<span class="phrase"><a name="math_toolkit.pol_ref.policy_defaults.boost_math_promote_float_policy"></a></span><a class="link" href="policy_defaults.html#math_toolkit.pol_ref.policy_defaults.boost_math_promote_float_policy">BOOST_MATH_PROMOTE_FLOAT_POLICY</a>
|
||||
</h6>
|
||||
<p>
|
||||
Determines whether <code class="computeroutput"><span class="keyword">float</span></code> types
|
||||
get promoted to <code class="computeroutput"><span class="keyword">double</span></code> internally
|
||||
to ensure maximum precision in the result, defaults to <code class="computeroutput"><span class="keyword">true</span></code>,
|
||||
but can be set to <code class="computeroutput"><span class="keyword">false</span></code> to turn
|
||||
promotion of <code class="computeroutput"><span class="keyword">float</span></code>'s off.
|
||||
</p>
|
||||
<h6>
|
||||
<a name="math_toolkit.pol_ref.policy_defaults.h10"></a>
|
||||
<span class="phrase"><a name="math_toolkit.pol_ref.policy_defaults.boost_math_promote_double_policy"></a></span><a class="link" href="policy_defaults.html#math_toolkit.pol_ref.policy_defaults.boost_math_promote_double_policy">BOOST_MATH_PROMOTE_DOUBLE_POLICY</a>
|
||||
</h6>
|
||||
<p>
|
||||
Determines whether <code class="computeroutput"><span class="keyword">double</span></code> types
|
||||
get promoted to <code class="computeroutput"><span class="keyword">long</span> <span class="keyword">double</span></code>
|
||||
internally to ensure maximum precision in the result, defaults to <code class="computeroutput"><span class="keyword">true</span></code>, but can be set to <code class="computeroutput"><span class="keyword">false</span></code>
|
||||
to turn promotion of <code class="computeroutput"><span class="keyword">double</span></code>'s
|
||||
off.
|
||||
</p>
|
||||
<h6>
|
||||
<a name="math_toolkit.pol_ref.policy_defaults.h11"></a>
|
||||
<span class="phrase"><a name="math_toolkit.pol_ref.policy_defaults.boost_math_discrete_quantile_pol"></a></span><a class="link" href="policy_defaults.html#math_toolkit.pol_ref.policy_defaults.boost_math_discrete_quantile_pol">BOOST_MATH_DISCRETE_QUANTILE_POLICY</a>
|
||||
</h6>
|
||||
<p>
|
||||
Determines how discrete quantiles return their results: either as an integer,
|
||||
or as a real value, can be set to one of the enumerated values: <code class="computeroutput"><span class="identifier">real</span></code>, <code class="computeroutput"><span class="identifier">integer_round_outwards</span></code>,
|
||||
<code class="computeroutput"><span class="identifier">integer_round_inwards</span></code>, <code class="computeroutput"><span class="identifier">integer_round_down</span></code>, <code class="computeroutput"><span class="identifier">integer_round_up</span></code>,
|
||||
<code class="computeroutput"><span class="identifier">integer_round_nearest</span></code>. Defaults
|
||||
to <code class="computeroutput"><span class="identifier">integer_round_outwards</span></code>.
|
||||
</p>
|
||||
<h6>
|
||||
<a name="math_toolkit.pol_ref.policy_defaults.h12"></a>
|
||||
<span class="phrase"><a name="math_toolkit.pol_ref.policy_defaults.boost_math_assert_undefined_poli"></a></span><a class="link" href="policy_defaults.html#math_toolkit.pol_ref.policy_defaults.boost_math_assert_undefined_poli">BOOST_MATH_ASSERT_UNDEFINED_POLICY</a>
|
||||
</h6>
|
||||
<p>
|
||||
Determines whether functions that are mathematically undefined for a specific
|
||||
distribution compile or raise a static (i.e. compile-time) assertion. Defaults
|
||||
to <code class="computeroutput"><span class="keyword">true</span></code>: meaning that any mathematically
|
||||
undefined function will not compile. When set to <code class="computeroutput"><span class="keyword">false</span></code>
|
||||
then the function will compile but return the result of a domain error: this
|
||||
can be useful for some generic code, that needs to work with all distributions
|
||||
and determine at runtime whether or not a particular property is well defined.
|
||||
</p>
|
||||
<h6>
|
||||
<a name="math_toolkit.pol_ref.policy_defaults.h13"></a>
|
||||
<span class="phrase"><a name="math_toolkit.pol_ref.policy_defaults.boost_math_max_series_iteration_"></a></span><a class="link" href="policy_defaults.html#math_toolkit.pol_ref.policy_defaults.boost_math_max_series_iteration_">BOOST_MATH_MAX_SERIES_ITERATION_POLICY</a>
|
||||
</h6>
|
||||
<p>
|
||||
Determines how many series iterations a special function is permitted to
|
||||
perform before it gives up and returns an <a class="link" href="../error_handling.html#math_toolkit.error_handling.evaluation_error">evaluation_error</a>:
|
||||
Defaults to 1000000.
|
||||
</p>
|
||||
<h6>
|
||||
<a name="math_toolkit.pol_ref.policy_defaults.h14"></a>
|
||||
<span class="phrase"><a name="math_toolkit.pol_ref.policy_defaults.boost_math_max_root_iteration_po"></a></span><a class="link" href="policy_defaults.html#math_toolkit.pol_ref.policy_defaults.boost_math_max_root_iteration_po">BOOST_MATH_MAX_ROOT_ITERATION_POLICY</a>
|
||||
</h6>
|
||||
<p>
|
||||
Determines how many root-finding iterations a special function is permitted
|
||||
to perform before it gives up and returns an <a class="link" href="../error_handling.html#math_toolkit.error_handling.evaluation_error">evaluation_error</a>:
|
||||
Defaults to 200.
|
||||
</p>
|
||||
<h6>
|
||||
<a name="math_toolkit.pol_ref.policy_defaults.h15"></a>
|
||||
<span class="phrase"><a name="math_toolkit.pol_ref.policy_defaults.example"></a></span><a class="link" href="policy_defaults.html#math_toolkit.pol_ref.policy_defaults.example">Example</a>
|
||||
</h6>
|
||||
<p>
|
||||
Suppose we want overflow errors to set <code class="computeroutput"><span class="special">::</span><span class="identifier">errno</span></code> and return an infinity, discrete
|
||||
quantiles to return a real-valued result (rather than round to integer),
|
||||
and for mathematically undefined functions to compile, but return a domain
|
||||
error. Then we could add the following to boost/math/tools/user.hpp:
|
||||
</p>
|
||||
<pre class="programlisting"><span class="preprocessor">#define</span> <span class="identifier">BOOST_MATH_OVERFLOW_ERROR_POLICY</span> <span class="identifier">errno_on_error</span>
|
||||
<span class="preprocessor">#define</span> <span class="identifier">BOOST_MATH_DISCRETE_QUANTILE_POLICY</span> <span class="identifier">real</span>
|
||||
<span class="preprocessor">#define</span> <span class="identifier">BOOST_MATH_ASSERT_UNDEFINED_POLICY</span> <span class="keyword">false</span>
|
||||
</pre>
|
||||
<p>
|
||||
or we could place these definitions <span class="bold"><strong>before</strong></span>
|
||||
</p>
|
||||
<pre class="programlisting"><span class="preprocessor">#include</span> <span class="special"><</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">math</span><span class="special">/</span><span class="identifier">distributions</span><span class="special">/</span><span class="identifier">normal</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">></span>
|
||||
<span class="keyword">using</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">math</span><span class="special">::</span><span class="identifier">normal_distribution</span><span class="special">;</span>
|
||||
</pre>
|
||||
<p>
|
||||
in a source .cpp file.
|
||||
</p>
|
||||
</div>
|
||||
<table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr>
|
||||
<td align="left"></td>
|
||||
<td align="right"><div class="copyright-footer">Copyright © 2006-2010, 2012-2014 Nikhar Agrawal,
|
||||
Anton Bikineev, Paul A. Bristow, Marco Guazzone, Christopher Kormanyos, Hubert
|
||||
Holin, Bruno Lalande, John Maddock, Jeremy Murphy, Johan Råde, Gautam Sewani,
|
||||
Benjamin Sobotta, Thijs van den Berg, Daryle Walker and Xiaogang Zhang<p>
|
||||
Distributed under the Boost Software License, Version 1.0. (See accompanying
|
||||
file LICENSE_1_0.txt or copy at <a href="http://www.boost.org/LICENSE_1_0.txt" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>)
|
||||
</p>
|
||||
</div></td>
|
||||
</tr></table>
|
||||
<hr>
|
||||
<div class="spirit-nav">
|
||||
<a accesskey="p" href="iteration_pol.html"><img src="../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../pol_ref.html"><img src="../../../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../../index.html"><img src="../../../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="namespace_pol.html"><img src="../../../../../../doc/src/images/next.png" alt="Next"></a>
|
||||
</div>
|
||||
</body>
|
||||
</html>
|
||||
@@ -0,0 +1,110 @@
|
||||
<html>
|
||||
<head>
|
||||
<meta http-equiv="Content-Type" content="text/html; charset=US-ASCII">
|
||||
<title>Precision Policies</title>
|
||||
<link rel="stylesheet" href="../../math.css" type="text/css">
|
||||
<meta name="generator" content="DocBook XSL Stylesheets V1.79.1">
|
||||
<link rel="home" href="../../index.html" title="Math Toolkit 2.5.1">
|
||||
<link rel="up" href="../pol_ref.html" title="Policy Reference">
|
||||
<link rel="prev" href="discrete_quant_ref.html" title="Discrete Quantile Policies">
|
||||
<link rel="next" href="iteration_pol.html" title="Iteration Limits Policies">
|
||||
</head>
|
||||
<body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF">
|
||||
<table cellpadding="2" width="100%"><tr>
|
||||
<td valign="top"><img alt="Boost C++ Libraries" width="277" height="86" src="../../../../../../boost.png"></td>
|
||||
<td align="center"><a href="../../../../../../index.html">Home</a></td>
|
||||
<td align="center"><a href="../../../../../../libs/libraries.htm">Libraries</a></td>
|
||||
<td align="center"><a href="http://www.boost.org/users/people.html">People</a></td>
|
||||
<td align="center"><a href="http://www.boost.org/users/faq.html">FAQ</a></td>
|
||||
<td align="center"><a href="../../../../../../more/index.htm">More</a></td>
|
||||
</tr></table>
|
||||
<hr>
|
||||
<div class="spirit-nav">
|
||||
<a accesskey="p" href="discrete_quant_ref.html"><img src="../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../pol_ref.html"><img src="../../../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../../index.html"><img src="../../../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="iteration_pol.html"><img src="../../../../../../doc/src/images/next.png" alt="Next"></a>
|
||||
</div>
|
||||
<div class="section">
|
||||
<div class="titlepage"><div><div><h3 class="title">
|
||||
<a name="math_toolkit.pol_ref.precision_pol"></a><a class="link" href="precision_pol.html" title="Precision Policies">Precision Policies</a>
|
||||
</h3></div></div></div>
|
||||
<p>
|
||||
There are two equivalent policies that effect the <span class="emphasis"><em>working precision</em></span>
|
||||
used to calculate results, these policies both default to 0 - meaning calculate
|
||||
to the maximum precision available in the type being used - but can be set
|
||||
to other values to cause lower levels of precision to be used. One might
|
||||
want to trade precision for evaluation speed.
|
||||
</p>
|
||||
<pre class="programlisting"><span class="keyword">namespace</span> <span class="identifier">boost</span><span class="special">{</span> <span class="keyword">namespace</span> <span class="identifier">math</span><span class="special">{</span> <span class="keyword">namespace</span> <span class="identifier">policies</span><span class="special">{</span>
|
||||
|
||||
<span class="keyword">template</span> <span class="special"><</span><span class="keyword">int</span> <span class="identifier">N</span><span class="special">></span>
|
||||
<span class="identifier">digits10</span><span class="special">;</span>
|
||||
|
||||
<span class="keyword">template</span> <span class="special"><</span><span class="keyword">int</span> <span class="identifier">N</span><span class="special">></span>
|
||||
<span class="identifier">digits2</span><span class="special">;</span>
|
||||
|
||||
<span class="special">}}}</span> <span class="comment">// namespaces</span>
|
||||
</pre>
|
||||
<p>
|
||||
As you would expect, <span class="emphasis"><em>digits10</em></span> specifies the number of
|
||||
decimal digits to use, and <span class="emphasis"><em>digits2</em></span> the number of binary
|
||||
digits. Internally, whichever is used, the precision is always converted
|
||||
to <span class="emphasis"><em>binary digits</em></span>.
|
||||
</p>
|
||||
<p>
|
||||
These policies are specified at compile-time, because many of the special
|
||||
functions use compile-time-dispatch to select which approximation to use
|
||||
based on the precision requested and the numeric type being used.
|
||||
</p>
|
||||
<p>
|
||||
For example we could calculate <code class="computeroutput"><span class="identifier">tgamma</span></code>
|
||||
to approximately 5 decimal digits using:
|
||||
</p>
|
||||
<pre class="programlisting"><span class="preprocessor">#include</span> <span class="special"><</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">math</span><span class="special">/</span><span class="identifier">special_functions</span><span class="special">/</span><span class="identifier">gamma</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">></span>
|
||||
<span class="keyword">using</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">math</span><span class="special">::</span><span class="identifier">tgamma</span><span class="special">;</span>
|
||||
<span class="keyword">using</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">math</span><span class="special">::</span><span class="identifier">policies</span><span class="special">::</span><span class="identifier">policy</span><span class="special">;</span>
|
||||
<span class="keyword">using</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">math</span><span class="special">::</span><span class="identifier">policies</span><span class="special">::</span><span class="identifier">digits10</span><span class="special">;</span>
|
||||
|
||||
<span class="keyword">typedef</span> <span class="identifier">policy</span><span class="special"><</span><span class="identifier">digits10</span><span class="special"><</span><span class="number">5</span><span class="special">></span> <span class="special">></span> <span class="identifier">my_pol_5</span><span class="special">;</span> <span class="comment">// Define a new, non-default, policy</span>
|
||||
<span class="comment">// to calculate tgamma to accuracy of approximately 5 decimal digits.</span>
|
||||
</pre>
|
||||
<p>
|
||||
Or again using helper function <code class="computeroutput"><span class="identifier">make_policy</span></code>:
|
||||
</p>
|
||||
<pre class="programlisting"><span class="preprocessor">#include</span> <span class="special"><</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">math</span><span class="special">/</span><span class="identifier">special_functions</span><span class="special">/</span><span class="identifier">gamma</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">></span>
|
||||
<span class="keyword">using</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">math</span><span class="special">::</span><span class="identifier">tgamma</span><span class="special">;</span>
|
||||
|
||||
<span class="keyword">using</span> <span class="keyword">namespace</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">math</span><span class="special">::</span><span class="identifier">policies</span><span class="special">;</span>
|
||||
|
||||
<span class="keyword">double</span> <span class="identifier">t</span> <span class="special">=</span> <span class="identifier">tgamma</span><span class="special">(</span><span class="number">12</span><span class="special">,</span> <span class="identifier">policy</span><span class="special"><</span><span class="identifier">digits10</span><span class="special"><</span><span class="number">5</span><span class="special">></span> <span class="special">>());</span> <span class="comment">// Concise make_policy.</span>
|
||||
</pre>
|
||||
<p>
|
||||
And for a quantile of a distribution to approximately 25-bit precision:
|
||||
</p>
|
||||
<pre class="programlisting"><span class="preprocessor">#include</span> <span class="special"><</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">math</span><span class="special">/</span><span class="identifier">distributions</span><span class="special">/</span><span class="identifier">normal</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">></span>
|
||||
<span class="keyword">using</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">math</span><span class="special">::</span><span class="identifier">normal_distribution</span><span class="special">;</span>
|
||||
|
||||
<span class="keyword">using</span> <span class="keyword">namespace</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">math</span><span class="special">::</span><span class="identifier">policies</span><span class="special">;</span>
|
||||
|
||||
<span class="keyword">const</span> <span class="keyword">int</span> <span class="identifier">bits</span> <span class="special">=</span> <span class="number">25</span><span class="special">;</span> <span class="comment">// approximate precision.</span>
|
||||
|
||||
<span class="keyword">double</span> <span class="identifier">q</span> <span class="special">=</span> <span class="identifier">quantile</span><span class="special">(</span>
|
||||
<span class="identifier">normal_distribution</span><span class="special"><</span><span class="keyword">double</span><span class="special">,</span> <span class="identifier">policy</span><span class="special"><</span><span class="identifier">digits2</span><span class="special"><</span><span class="identifier">bits</span><span class="special">></span> <span class="special">></span> <span class="special">>(),</span>
|
||||
<span class="number">0.05</span><span class="special">);</span> <span class="comment">// 5% quantile.</span>
|
||||
</pre>
|
||||
</div>
|
||||
<table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr>
|
||||
<td align="left"></td>
|
||||
<td align="right"><div class="copyright-footer">Copyright © 2006-2010, 2012-2014 Nikhar Agrawal,
|
||||
Anton Bikineev, Paul A. Bristow, Marco Guazzone, Christopher Kormanyos, Hubert
|
||||
Holin, Bruno Lalande, John Maddock, Jeremy Murphy, Johan Råde, Gautam Sewani,
|
||||
Benjamin Sobotta, Thijs van den Berg, Daryle Walker and Xiaogang Zhang<p>
|
||||
Distributed under the Boost Software License, Version 1.0. (See accompanying
|
||||
file LICENSE_1_0.txt or copy at <a href="http://www.boost.org/LICENSE_1_0.txt" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>)
|
||||
</p>
|
||||
</div></td>
|
||||
</tr></table>
|
||||
<hr>
|
||||
<div class="spirit-nav">
|
||||
<a accesskey="p" href="discrete_quant_ref.html"><img src="../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../pol_ref.html"><img src="../../../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../../index.html"><img src="../../../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="iteration_pol.html"><img src="../../../../../../doc/src/images/next.png" alt="Next"></a>
|
||||
</div>
|
||||
</body>
|
||||
</html>
|
||||
Reference in New Issue
Block a user