mirror of
https://github.com/saitohirga/WSJT-X.git
synced 2024-09-06 21:36:44 -04:00
154 lines
5.4 KiB
Plaintext
154 lines
5.4 KiB
Plaintext
[section:issues Known Issues, and TODO List]
|
|
|
|
Predominantly this is a TODO list, or a list of possible
|
|
future enhancements. Items labled "High Priority" effect
|
|
the proper functioning of the component, and should be fixed
|
|
as soon as possible. Items labled "Medium Priority" are
|
|
desirable enhancements, often pertaining to the performance
|
|
of the component, but do not effect it's accuracy or functionality.
|
|
Items labled "Low Priority" should probably be investigated at
|
|
some point. Such classifications are obviously highly subjective.
|
|
|
|
If you don't see a component listed here, then we don't have any known
|
|
issues with it.
|
|
|
|
[h4 Derivatives of Bessel functions (and their zeros)]
|
|
|
|
Potentially, there could be native support
|
|
for `cyl_bessel_j_prime()` and `cyl_neumann_prime()`.
|
|
One could also imagine supporting the zeros
|
|
thereof, but they might be slower to calculate
|
|
since root bracketing might be needed instead
|
|
of Newton iteration (for the lack of 2nd derivatives).
|
|
|
|
Since Boost.Math's Bessel functions are so excellent,
|
|
the quick way to `cyl_bessel_j_prime()` and
|
|
`cyl_neumann_prime()` would be via relationship with
|
|
`cyl_bessel_j()` and `cyl_neumann()`.
|
|
|
|
[h4 tgamma]
|
|
|
|
* Can the __lanczos be optimized any further? (low priority)
|
|
|
|
[h4 Incomplete Beta]
|
|
|
|
* Investigate Didonato and Morris' asymptotic expansion for large a and b
|
|
(medium priority).
|
|
|
|
[h4 Inverse Gamma]
|
|
|
|
* Investigate whether we can skip iteration altogether if the first approximation
|
|
is good enough (Medium Priority).
|
|
|
|
[h4 Polynomials]
|
|
|
|
* The Legendre and Laguerre Polynomials have surprisingly different error
|
|
rates on different platforms, considering they are evaluated with only
|
|
basic arithmetic operations. Maybe this is telling us something, or maybe not
|
|
(Low Priority).
|
|
|
|
[h4 Elliptic Integrals]
|
|
|
|
* [para Carlson's algorithms (mainly R[sub J]) are somewhat prone to
|
|
internal overflow/underflow when the arguments are very large or small.
|
|
The homogeneity relations:]
|
|
[para R[sub F](ka, kb, kc) = k[super -1/2] R[sub F](a, b, c)]
|
|
[para and]
|
|
[para R[sub J](ka, kb, kc, kr) = k[super -3/2] R[sub J](a, b, c, r)]
|
|
[para could be used to sidestep trouble here: provided the problem domains
|
|
can be accurately identified. (Medium Priority).]
|
|
* There are a several other integrals: Bulirsch's ['el] functions that could
|
|
be implemented using Carlson's integrals (Low Priority).
|
|
* The integrals K(k) and E(k) could be implemented using rational
|
|
approximations (both for efficiency and accuracy),
|
|
assuming we can find them. (Medium Priority).
|
|
|
|
[h4 Owen's T Function]
|
|
|
|
There is a problem area at arbitrary precision when ['a] is very close to 1. However, note that
|
|
the value for ['T(h, 1)] is well known and easy to compute, and if we replaced the
|
|
['a[super k]] terms in series T1, T2 or T4 by ['(a[super k] - 1)] then we would have the
|
|
difference between ['T(h, a)] and ['T(h, 1)]. Unfortunately this doesn't improve the
|
|
convergence of those series in that area. It certainly looks as though a new series in terms
|
|
of ['(1-a)[super k]] is both possible and desirable in this area, but it remains elusive at present.
|
|
|
|
[h4 Jocobi elliptic functions]
|
|
|
|
These are useful in engineering applications - we have had a request to add these.
|
|
|
|
[h4 Statistical distributions]
|
|
|
|
* Student's t Perhaps switch to normal distribution
|
|
as a better approximation for very large degrees of freedom?
|
|
|
|
[h4 Feature Requests]
|
|
|
|
We have a request for the Lambert W function, see [@https://svn.boost.org/trac/boost/ticket/11027 #11027].
|
|
|
|
The following table lists distributions that are found in other packages
|
|
but which are not yet present here, the more frequently the distribution
|
|
is found, the higher the priority for implementing it:
|
|
|
|
[table
|
|
[[Distribution][R][Mathematica 6][NIST][Regress+][Matlab]]
|
|
|
|
[/3 votes:]
|
|
[[Geometric][X][X][-][-][X]]
|
|
|
|
[/2 votes:]
|
|
[[Multinomial][X][-][-][-][X]]
|
|
[[Tukey Lambda][X][-][X][-][-]]
|
|
[[Half Normal / Folded Normal][-][X][-][X][-]]
|
|
[[Chi][-][X][-][X][-]]
|
|
[[Gumbel][-][X][-][X][-]]
|
|
[[Discrete Uniform][-][X][-][-][X]]
|
|
[[Log Series][-][X][-][X][-]]
|
|
[[Nakagami (generalised Chi)][-][-][-][X][X]]
|
|
|
|
[/1 vote:]
|
|
[[Log Logistic][-][-][-][-][X]]
|
|
[[Tukey (Studentized range)][X][-][-][-][-]]
|
|
[[Wilcoxon rank sum][X][-][-][-][-]]
|
|
[[Wincoxon signed rank][X][-][-][-][-]]
|
|
[[Non-central Beta][X][-][-][-][-]]
|
|
[[Maxwell][-][X][-][-][-]]
|
|
[[Beta-Binomial][-][X][-][-][-]]
|
|
[[Beta-negative Binomial][-][X][-][-][-]]
|
|
[[Zipf][-][X][-][-][-]]
|
|
[[Birnbaum-Saunders / Fatigue Life][-][-][X][-][-]]
|
|
[[Double Exponential][-][-][X][-][-]]
|
|
[[Power Normal][-][-][X][-][-]]
|
|
[[Power Lognormal][-][-][X][-][-]]
|
|
[[Cosine][-][-][-][X][-]]
|
|
[[Double Gamma][-][-][-][X][-]]
|
|
[[Double Weibul][-][-][-][X][-]]
|
|
[[Hyperbolic Secant][-][-][-][X][-]]
|
|
[[Semicircular][-][-][-][X][-]]
|
|
[[Bradford][-][-][-][X][-]]
|
|
[[Birr / Fisk][-][-][-][X][-]]
|
|
[[Reciprocal][-][-][-][X][-]]
|
|
|
|
[/0 votes but useful anyway?]
|
|
[[Kolmogorov Distribution][-][-][-][-][-]]
|
|
]
|
|
|
|
Also asked for more than once:
|
|
|
|
* Add support for interpolated distributions, possibly combine with numeric
|
|
integration and differentiation.
|
|
* Add support for bivariate and multivariate distributions: most especially the normal.
|
|
* Add support for the log of the cdf and pdf:
|
|
this is mainly a performance optimisation since we can avoid
|
|
some special function calls for some distributions
|
|
by returning the log of the result.
|
|
|
|
[endsect] [/section:issues Known Issues, and Todo List]
|
|
|
|
[/
|
|
Copyright 2006, 2010 John Maddock and Paul A. Bristow.
|
|
Distributed under the Boost Software License, Version 1.0.
|
|
(See accompanying file LICENSE_1_0.txt or copy at
|
|
http://www.boost.org/LICENSE_1_0.txt).
|
|
]
|
|
|