#include "../matplotlibcpp.h"
#include
#include
namespace plt = matplotlibcpp;
int main()
{
const int n = 20;
std::vector<:vector>> matrix;
for (int i = 0; i < n; ++i) {
std::vector row;
for (int j = 0; j < n; ++j) {
if (i == j)
row.push_back(-2);
else if (j == i - 1 || j == i + 1)
row.push_back(1);
else
row.push_back(0);
}
matrix.push_back(row);
}
plt::spy(matrix, 5, {{"marker", "o"}});
plt::show();
return 0;
}