#define _USE_MATH_DEFINES

#include "matplotlibcpp/matplotlibcpp.h"

#include <cmath>

#include <iostream>

using namespace std;

namespace plt = matplotlibcpp;

int main() {

// Prepare data.

int n = 5000;

std::vector<double> x(n), y(n), z(n), w(n, 2);

for (int i = 0; i < n; ++i) {

x.at(i) = i * i;

y.at(i) = sin(2 * M_PI * i / 360.0);

z.at(i) = log(i);

}

// Prepare keywords to pass to PolyCollection. See

// https://matplotlib.org/api/_as_gen/matplotlib.axes.Axes.fill_between.html

std::map<string, string> keywords;

keywords["alpha"] = "0.4";

keywords["color"] = "grey";

keywords["hatch"] = "-";

plt::init(); // Required for Python 3 (doesn't hurt for Python 2)

plt::fill_between(x, y, z, keywords);

plt::show();

}