Generalize the equalization plotting code and add group delay plot

Moving towards some useful generic plotting templates.

Phase plots are now fixed to +/- Pi range and the phase axis is now in
units of Pi.

git-svn-id: svn+ssh://svn.code.sf.net/p/wsjt/wsjt/branches/wsjtx@7575 ab8295b8-cf94-4d9e-aec4-7959e3be5d79
This commit is contained in:
Bill Somerville 2017-02-22 02:20:11 +00:00
parent d62dacd7e2
commit 5d9ac3966b
1 changed files with 180 additions and 63 deletions

View File

@ -3,6 +3,8 @@
#include <iterator>
#include <algorithm>
#include <fstream>
#include <limits>
#include <cmath>
#include <QDir>
#include <QVector>
@ -19,88 +21,211 @@
namespace
{
float constexpr PI = 3.1415927f;
char const * const title = "Phase Equalization";
size_t constexpr intervals = 144;
// plot data loaders - wraps a plot providing value_type and
// push_back so that a std::back_inserter output iterator can be
// used to load plot data
template<typename T>
template<typename T, typename A>
struct plot_data_loader
{
public:
typedef T value_type;
plot_data_loader (QCustomPlot * plot, int graph_index)
// the adjust argument is a function that is passed the plot
// pointer, the graph index and a data point, it returns a
// possibly adjusted data point and can modify the graph including
// adding extra points or gaps (quiet_NaN)
plot_data_loader (QCustomPlot * plot, int graph_index, A adjust)
: plot_ {plot}
, index_ {graph_index }
, index_ {graph_index}
, adjust_ (adjust)
{
}
// load point into graph
void push_back (value_type const& d)
{
plot_->graph (index_)->data ()->add (d);
plot_->graph (index_)->data ()->add (adjust_ (plot_, index_, d));
}
private:
QCustomPlot * plot_;
int index_;
A adjust_;
};
// helper function template to make a plot_data_loader instance
template<typename A>
auto make_plot_data_loader (QCustomPlot * plot, int index, A adjust)
-> plot_data_loader<QCPGraphData, decltype (adjust)>
{
return plot_data_loader<QCPGraphData, decltype (adjust)> {plot, index, adjust};
}
// identity adjust function when none is needed in the above
// instantiation helper
QCPGraphData adjust_identity (QCustomPlot *, int, QCPGraphData const& v) {return v;}
// a plot_data_loader adjustment function that wraps Y values of
// (-1..+1) plotting discontinuities as gaps in the graph data
auto wrap_pi = [] (QCustomPlot * plot, int index, QCPGraphData d)
{
double constexpr limit {1};
static unsigned wrap_count {0};
static double last_x {std::numeric_limits<double>::lowest ()};
d.value += 2 * limit * wrap_count;
if (d.value > limit)
{
// insert a gap in the graph
plot->graph (index)->data ()->add ({last_x + (d.key - last_x) / 2
, std::numeric_limits<double>::quiet_NaN ()});
while (d.value > limit)
{
--wrap_count;
d.value -= 2 * limit;
}
}
else if (d.value < -limit)
{
// insert a gap into the graph
plot->graph (index)->data ()->add ({last_x + (d.key - last_x) / 2
, std::numeric_limits<double>::quiet_NaN ()});
while (d.value < -limit)
{
++wrap_count;
d.value += 2 * limit;
}
}
last_x = d.key;
return d;
};
typedef plot_data_loader<QCPGraphData> graph_loader_type;
// generate points of type T for a 5 term polynomial for x in
// (-1..+1) with N intervals and function S to scale X
// generate points of type R from a function of type F for X in
// (-1..+1) with N intervals and function of type SX to scale X and
// of type SY to scale Y
//
// it is up to the user to call the generator sufficient times which
// is interval+1 times to reach +1
template<typename R, typename T, typename S>
struct poly_generator
template<typename R, typename F, typename SX, typename SY>
struct graph_generator
{
public:
poly_generator (QVector<T> const& coeffs, size_t intervals, S scaling = [] (T x) {return x;})
graph_generator (F f, size_t intervals, SX x_scaling, SY y_scaling)
: x_ {0}
, f_ (f)
, intervals_ {intervals}
, scaling_ (scaling)
, coeffs_ {coeffs}
, x_scaling_ (x_scaling)
, y_scaling_ (y_scaling)
{
}
R operator () ()
{
T x {x_++ * 2.f / intervals_ - 1.f};
return {scaling_ (x), coeffs_[0] + x * (coeffs_[1] + x * (coeffs_[2] + x * (coeffs_[3] + x * coeffs_[4])))};
typename F::value_type x {x_++ * 2.f / intervals_ - 1.f};
return {x_scaling_ (x), y_scaling_ (f_ (x))};
}
size_t intervals () const {return intervals_;}
private:
int x_;
F f_;
size_t intervals_;
S scaling_;
QVector<T> coeffs_;
SX x_scaling_;
SY y_scaling_;
};
// make our n=5 polynomial single precision FP generator of
// helper function template to make a graph_generator instance for
// QCPGraphData type points with intervals intervals
template<typename S>
auto make_poly_generator (QVector<float> const& coeffs, S x_scaling)
-> poly_generator<QCPGraphData, float, decltype (x_scaling)>
template<typename F, typename SX, typename SY>
auto make_graph_generator (F function, SX x_scaling, SY y_scaling)
-> graph_generator<QCPGraphData, F, decltype (x_scaling), decltype (y_scaling)>
{
return poly_generator<QCPGraphData, float, decltype (x_scaling)> {coeffs, intervals, x_scaling};
return graph_generator<QCPGraphData, F, decltype (x_scaling), decltype (y_scaling)>
{function, intervals, x_scaling, y_scaling};
}
// a lambda that scales the X axis appropriately
auto x_scaling = [] (float x) -> float {return 1500. + 1000 * x;};
// template function object for a polynomial with coefficients
template<typename C>
class polynomial
{
public:
typedef typename C::value_type value_type;
explicit polynomial (C const& coefficients)
: c_ {coefficients}
{
}
value_type operator () (value_type const& x)
{
value_type y {};
for (typename C::size_type i = c_.size (); i > 0; --i)
{
y = c_[i - 1] + x * y;
}
return y;
}
private:
C c_;
};
// helper function template to instantiate a polynomial instance
template<typename C>
auto make_polynomial (C const& coefficients) -> polynomial<C>
{
return polynomial<C> (coefficients);
}
// template function object for a group delay with coefficients
template<typename C>
class group_delay
{
public:
typedef typename C::value_type value_type;
explicit group_delay (C const& coefficients)
: c_ {coefficients}
{
}
value_type operator () (value_type const& x)
{
value_type tau {};
for (typename C::size_type i = 2; i < c_.size (); ++i)
{
tau += i * c_[i] * std::pow (x, i - 1);
}
return -1 / (2 * PI) * tau;
}
private:
C c_;
};
// helper function template to instantiate a group_delay function
// object
template<typename C>
auto make_group_delay (C const& coefficients) -> group_delay<C>
{
return group_delay<C> (coefficients);
}
// handy identity function
template<typename T> T identity (T const& v) {return v;}
// a lambda that scales the X axis from normalized to (500..2500)Hz
auto freq_scaling = [] (float v) -> float {return 1500.f + 1000.f * v;};
// a lambda that scales the phase Y axis from radians to units of Pi
auto pi_scaling = [] (float v) -> float {return v / PI;};
}
// read a phase point line from a stream
std::istream& operator >> (std::istream& is, graph_loader_type::value_type& v)
// read a phase point line from a stream (pcoeff file)
std::istream& operator >> (std::istream& is, QCPGraphData& v)
{
float pp, sigmay; // discard these
is >> v.key >> pp >> v.value >> sigmay;
v.key = 1500. + 1000. * v.key; // scale frequency to Hz
v.value /= PI; // scale to units of Pi
return is;
}
@ -179,11 +304,18 @@ PhaseEqualizationDialog::impl::impl (PhaseEqualizationDialog * self
layout_.addWidget (&plot_);
plot_.xAxis->setLabel (tr ("Freq (Hz)"));
plot_.yAxis->setLabel (tr ("Phase (Radians)"));
plot_.legend->setVisible (true);
plot_.setInteractions (QCP::iRangeDrag | QCP::iRangeZoom);
plot_.xAxis->setRange (500, 2500);
plot_.yAxis->setLabel (tr ("Phase (Π)"));
plot_.yAxis->setRange (-1, +1);
plot_.yAxis2->setLabel (tr ("Delay (ms)"));
plot_.axisRect ()->setRangeDrag (Qt::Vertical);
plot_.axisRect ()->setRangeZoom (Qt::Vertical);
plot_.yAxis2->setVisible (true);
plot_.axisRect ()->setRangeDragAxes (0, plot_.yAxis2);
plot_.axisRect ()->setRangeZoomAxes (0, plot_.yAxis2);
plot_.axisRect ()->insetLayout ()->setInsetAlignment (0, Qt::AlignBottom|Qt::AlignRight);
plot_.legend->setVisible (true);
plot_.setInteractions (QCP::iRangeDrag | QCP::iRangeZoom | QCP::iSelectPlottables);
plot_.addGraph ();
plot_.graph ()->setName (tr ("Measured"));
@ -201,8 +333,8 @@ PhaseEqualizationDialog::impl::impl (PhaseEqualizationDialog * self
plot_.graph ()->setName (tr ("Current"));
plot_.graph ()->setPen (QPen {Qt::green});
plot_.addGraph ();
plot_.graph ()->setName (tr ("Current as Used"));
plot_.addGraph (plot_.xAxis, plot_.yAxis2);
plot_.graph ()->setName (tr ("Group Delay"));
plot_.graph ()->setPen (QPen {Qt::darkGreen});
auto load_button = button_box_.addButton (tr ("Load ..."), QDialogButtonBox::ActionRole);
@ -242,9 +374,6 @@ PhaseEqualizationDialog::impl::impl (PhaseEqualizationDialog * self
plot_.graph (1)->setVisible (false);
plot_.graph (1)->removeFromLegend ();
plot_.graph (2)->rescaleAxes ();
plot_.graph (3)->rescaleValueAxis (true);
plot_.replot ();
}
});
@ -257,24 +386,18 @@ void PhaseEqualizationDialog::impl::plot_current ()
plot_.graph (2)->data ()->clear ();
plot_.graph (3)->data ()->clear ();
{
graph_loader_type graph {&plot_, 2};
std::generate_n (std::back_inserter (graph), intervals + 1, make_poly_generator (current_coefficients_, x_scaling));
// plot the current polynomial
auto graph = make_plot_data_loader (&plot_, 2, wrap_pi);
std::generate_n (std::back_inserter (graph), intervals + 1
, make_graph_generator (make_polynomial (current_coefficients_), freq_scaling, pi_scaling));
}
{
// plot the adjusted polynomial using only the three high order terms
graph_loader_type graph {&plot_, 3};
QVector<float> reduced {current_coefficients_};
reduced[0] = 0.f;
reduced[1] = 0.f;
std::generate_n (std::back_inserter (graph), intervals + 1, make_poly_generator (reduced, x_scaling));
// plot the group delay for the current polynomial
auto graph = make_plot_data_loader (&plot_, 3, adjust_identity);
std::generate_n (std::back_inserter (graph), intervals + 1
, make_graph_generator (make_group_delay (current_coefficients_), freq_scaling, identity<float>));
plot_.graph (3)->rescaleValueAxis ();
}
plot_.graph (2)->rescaleAxes ();
plot_.graph (3)->rescaleValueAxis (true);
if (plot_.graph (0)->dataCount ())
{
plot_.graph (0)->rescaleValueAxis (true);
plot_.graph (1)->rescaleValueAxis (true);
}
plot_.replot ();
}
@ -302,28 +425,22 @@ void PhaseEqualizationDialog::impl::plot ()
plot_.graph (1)->data ()->clear ();
{
// read the phase data to plot into graph 0
graph_loader_type graph {&plot_, 0};
std::istream_iterator<graph_loader_type::value_type> start {coeffs_source};
auto graph = make_plot_data_loader (&plot_, 0, adjust_identity);
std::istream_iterator<QCPGraphData> start {coeffs_source};
std::copy_n (start, intervals + 1, std::back_inserter (graph));
}
{
// generate the proposed polynomial plot in graph 1
graph_loader_type graph {&plot_, 1};
std::generate_n (std::back_inserter (graph), intervals + 1, make_poly_generator (new_coefficients_, x_scaling));
auto graph = make_plot_data_loader (&plot_, 1, wrap_pi);
std::generate_n (std::back_inserter (graph), intervals + 1
, make_graph_generator (make_polynomial (new_coefficients_), freq_scaling, pi_scaling));
}
plot_.graph (0)->setVisible (true);
plot_.graph (0)->addToLegend ();
plot_.graph (0)->rescaleAxes ();
plot_.graph (1)->setVisible (true);
plot_.graph (1)->addToLegend ();
plot_.graph (1)->rescaleValueAxis (true);
if (plot_.graph (2)->dataCount ())
{
plot_.graph (2)->rescaleValueAxis (true);
plot_.graph (3)->rescaleValueAxis (true);
}
plot_.replot ();
}
}