histogram/test/speed_gsl.cpp
2018-07-21 17:27:18 +02:00

77 lines
2.1 KiB
C++

// Copyright 2015-2017 Hans Dembinski
//
// 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)
#include <gsl/gsl_histogram.h>
#include <gsl/gsl_histogram2d.h>
#include <algorithm>
#include <cstdio>
#include <ctime>
#include <limits>
#include <memory>
#include <random>
std::unique_ptr<double[]> random_array(unsigned n, int type) {
std::unique_ptr<double[]> r(new double[n]);
std::default_random_engine gen(1);
if (type) { // type == 1
std::normal_distribution<> d(0.5, 0.3);
for (unsigned i = 0; i < n; ++i) r[i] = d(gen);
} else { // type == 0
std::uniform_real_distribution<> d(0.0, 1.0);
for (unsigned i = 0; i < n; ++i) r[i] = d(gen);
}
return r;
}
void compare_1d(unsigned n, int distrib) {
auto r = random_array(n, distrib);
double best = std::numeric_limits<double>::max();
for (unsigned k = 0; k < 20; ++k) {
gsl_histogram* h = gsl_histogram_alloc(100);
gsl_histogram_set_ranges_uniform(h, 0, 1);
auto t = clock();
for (unsigned i = 0; i < n; ++i) gsl_histogram_increment(h, r[i]);
t = clock() - t;
best = std::min(best, double(t) / CLOCKS_PER_SEC);
gsl_histogram_free(h);
}
printf("gsl %.3f\n", best);
}
void compare_2d(unsigned n, int distrib) {
auto r = random_array(n, distrib);
double best = std::numeric_limits<double>::max();
for (unsigned k = 0; k < 20; ++k) {
gsl_histogram2d* h = gsl_histogram2d_alloc(100, 100);
gsl_histogram2d_set_ranges_uniform(h, 0, 1, 0, 1);
auto t = clock();
for (unsigned i = 0; i < n / 2; ++i)
gsl_histogram2d_increment(h, r[2 * i], r[2 * i + 1]);
t = clock() - t;
best = std::min(best, double(t) / CLOCKS_PER_SEC);
gsl_histogram2d_free(h);
}
printf("gsl %.3f\n", best);
}
int main(int argc, char** argv) {
constexpr unsigned nfill = 6000000;
printf("1D\n");
printf("uniform distribution\n");
compare_1d(nfill, 0);
printf("normal distribution\n");
compare_1d(nfill, 1);
printf("2D\n");
printf("uniform distribution\n");
compare_2d(nfill, 0);
printf("normal distribution\n");
compare_2d(nfill, 1);
}