// plot(y) - the x-coordinates are implicitly set to [0,1,...,n)

// plt::plot({1,2,3,4});

// Prepare data for parametric plot.

int n = 5000; // number of data points

vector<double> x(n), y(n);

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

double t = 2 * M_PI * i / n;

x.at(i) = 16 * sin(t) * sin(t) * sin(t);

y.at(i) = 13 * cos(t) - 5 * cos(2 * t) - 2 * cos(3 * t) - cos(4 * t);

}

// plot() takes an arbitrary number of (x,y,format)-triples.

// x must be iterable (that is, anything providing begin(x) and end(x)),

// y must either be callable (providing operator() const) or iterable.

plt::plot(

x, y, "r-", x, [](double d) { return 12.5 + abs(sin(d)); }, "k-");

// plt::set_aspect(0.5);

plt::set_aspect_equal();

// show plots

plt::show();