Plotty: C++ Interface to Matplotlib

Principles

• plotty::plot(...) automatically creates a new figure
• plotty::show() shows the results of the plot
• calls to plotty::plot(...) go to the same plot until plotty::show() is called
• by default, calls to plotty::show() are blocking and execution continues only after the plot window is closed

Simple plot of a vector:

// Std Vector:
std::vector<double> v({1, 2, 3, 4});
plotty::plot(v);
plotty::show();

// Eigen Types:
Eigen::VectorXd w(100);
w.setRandom();
plotty::plot(w)
plotty::show();

Plot x and y

Eigen::VectorXd t(100);
t.setLinSpaced(100, 0, 20);
Eigen::VectorXd v(100);
v.setRandom();
plotty::plot(t, v);
plotty::show();

Subplots

plotty::subplot(3, 1, 1);
plotty::plot(v1);
plotty::subplot(3, 1, 2);
plotty::plot(v2);
plotty::subplot(3, 1, 3);
plotty::plot(v2);
plotty::plot();

Histogram

The histogram function only exposes the bins, data and type parameters of matplotlibs histogram function.

plotty::hist(v, 10, "bar");
plotty::show();

Formatting

All functions accept optional format arguments (plotty::plot(x, y, format) or plotty::plot(y, format)). The expected format strings are equivalent to the matplotlib format strings:

plotty::plot(t, v, "rx"); // red x'es
plotty::show();

Multiple open Plots

plotty::show(false) opens a non-blocking window. You have to open a new figure to get a second plot ( plotty::figure()). The final figure should be opened in blocking mode to keep all windows open.

plotty::plot(v1);
plotty::show(false); // show non-blocking

...

plotty::figure(); // new figure
plotty::plot(v2)
plotty::show(false); // open non-blocking

...

plotty::figure();
plotty::plot(v3);
plotty::show(); // blocking to keep figures 1-3 open.

plotty::figure() accepts a string argument that labels / identifies a specific plot.

Style and Labels

plotty::plot(t, x);
plotty::xlabel("time [s]");
plotty::ylabel("Position [m]");
plotty::title("Position over time");
plotty::xlim(t_start, t_end);
plotty::ylim(0, x_max);