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// (C) Copyright Nick Thompson 2020.
// Use, modification and distribution are subject to 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)
//
// Deliberately contains some unicode characters:
//
// boost-no-inspect
#include <iostream>
#include <boost/math/tools/ulps_plot.hpp>
#include <boost/core/demangle.hpp>
#include <boost/math/special_functions/airy.hpp>
using boost::math::tools::ulps_plot;
int main() {
using PreciseReal = long double;
using CoarseReal = float;
typedef boost::math::policies::policy<
boost::math::policies::promote_float<false>,
boost::math::policies::promote_double<false> >
no_promote_policy;
auto ai_coarse = [](CoarseReal x) {
return boost::math::airy_ai<CoarseReal>(x, no_promote_policy());
};
auto ai_precise = [](PreciseReal x) {
return boost::math::airy_ai<PreciseReal>(x, no_promote_policy());
};
std::string filename = "airy_ai_" + boost::core::demangle(typeid(CoarseReal).name()) + ".svg";
int samples = 10000;
// How many pixels wide do you want your .svg?
int width = 700;
// Near a root, we have unbounded relative error. So for functions with roots, we define an ULP clip:
PreciseReal clip = 2.5;
// Should we perturb the abscissas? i.e., should we compute the high precision function f at x,
// and the low precision function at the nearest representable x̂ to x?
// Or should we compute both the high precision and low precision function at a low precision representable x̂?
bool perturb_abscissas = false;
auto plot = ulps_plot<decltype(ai_precise), PreciseReal, CoarseReal>(ai_precise, CoarseReal(-3), CoarseReal(3), samples, perturb_abscissas);
// Note the argument chaining:
plot.clip(clip).width(width);
// Sometimes it's useful to set a title, but in many cases it's more useful to just use a caption.
//std::string title = "Airy Ai ULP plot at " + boost::core::demangle(typeid(CoarseReal).name()) + " precision";
//plot.title(title);
plot.vertical_lines(6);
plot.add_fn(ai_coarse);
// You can write the plot to a stream:
//std::cout << plot;
// Or to a file:
plot.write(filename);
// Don't like the default dark theme?
plot.background_color("white").font_color("black");
filename = "airy_ai_" + boost::core::demangle(typeid(CoarseReal).name()) + "_white.svg";
plot.write(filename);
// Don't like the envelope?
plot.ulp_envelope(false);
filename = "airy_ai_" + boost::core::demangle(typeid(CoarseReal).name()) + "_white_no_envelope.svg";
plot.write(filename);
}
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