third_party/matplotlib-cpp/examples/imshow.cpp

#define _USE_MATH_DEFINES
#include <cmath>
#include <iostream>
#include "../matplotlibcpp.h"

using namespace std;
namespace plt = matplotlibcpp;

int main()
{
    // Prepare data
    int ncols = 500, nrows = 300;
    std::vector<float> z(ncols * nrows);
    for (int j=0; j<nrows; ++j) {
        for (int i=0; i<ncols; ++i) {
            z.at(ncols * j + i) = std::sin(std::hypot(i - ncols/2, j - nrows/2));
        }
    }

    const float* zptr = &(z[0]);
    const int colors = 1;

    plt::title("My matrix");
    plt::imshow(zptr, nrows, ncols, colors);

    // Show plots
    plt::save("imshow.png");
    std::cout << "Result saved to 'imshow.png'.\n";
}