This project aims to replace matplotlibcpp using pybind11 as backend.
It is supposed to provide the user with almost full access to matplotlib features in C++, by implementing as many wrapper classes of matplotlib module as possible (like axes::Axes, figure::Figure). And its primary advantage over conventional matplotlibcpp is that the user can pass a variety of arguments as in the form of args and kwargs thanks to pybind11, without the need for coversion to map<string, string>, thus leading to more flexibility.
- pybind11(https://github.com/pybind/pybind11) >= 2.9.0
- compatible with matplotlib(https://matplotlib.org/stable/index.html) == 3.5.1 as of now
Just add include path to include directory of this project.
voidfunctions can be called in almost the same way as python code (remind yourself to append_aliteral to keyword arguments).- For
non-voidfunctions that return some objects, basically the user will need to capsulate arguments in::util::args_(arg1, arg2, ...) == pybind11:tupleand keyword arguments in::util::kwargs_("k1"_a = v1, "k2"_a = v2, ...) == pybind11::dict. The returned value is a corresponding wrapper class. Please refer to the examples below.- exception:
subplots, - conversion: Wrapper class of matplotlibcpp17 like ::container::BarContainer needs to be passed to python interpreter using
unwrap()method in args and kwargs.
- exception:
g++ hello_world.cpp -std=c++17 -I./include -I/usr/include/python3.x -I<path to pybind11> -lpython3.x
./a.outgives
From gallery/subplots_axes_and_figures/align_labels_demo.cpp.
auto plt = matplotlibcpp17::pyplot::import();
// corresponding wrapper class for returned value is implemented in this library
/// gs is of type gridspec::GridSpec
auto gs = GridSpec(2, 2);
// non-void function: capsulate args and kwargs in py::tuple and py::dict
/// pass wrapper class object like gs[0, :] of ::gridspec::SubplotSpec to the interpreter using .unwrap() method as python object
auto ax = fig.add_subplot(args_(gs(0, py::slice(0, 2, 1)).unwrap()));
// void function: no need to capsulate args and kwargs
ax.plot(arange(0, 1000000, 10000));
ax.set_ylabel("YLabel0");
ax.set_xlabel("XLabel0");From gallery/lines_bars_and_markers/bar_label_demo.cpp. Here subplots() returns tuple<Figure, Axes>.
auto [fig, ax] = plt.subplots();
// non-void function: capsulate args and kwargs in py::tuple and py::dict
auto p1 = ax.bar(args_(ind, menMeans, width),
kwargs_("yerr"_a = menStd, "label"_a = "Men"));
auto p2 = ax.bar(
args_(ind, womenMeans, width),
kwargs_("bottom"_a = menMeans, "yerr"_a = womenStd, "label"_a = "Women"));
ax.axhline(0, "color"_a = "grey", "linewidth"_a = 0.8);
ax.set_ylabel("Scores");
ax.set_title("Scores by group and gender");
ax.set_xticks(ind, py::make_tuple("G1", "G2", "G3", "G4", "G5"));
ax.legend();
// pass wrapper class object like p1 of ::container::BarContainer to the interpreter using .unwrap() method as python object
ax.bar_label(p1.unwrap(), "label_type"_a = "center");
ax.bar_label(p2.unwrap(), "label_type"_a = "center");
ax.bar_label(p2.unwrap());
plt.show();Fucntions like subplots, TBDs are overloaded because they return different types depending on the arguments. Here subplots() returns tuple<Figure, vector<Axes>>.
From gallery/lines_bars_and_markers
auto [fig, axes] =
plt.subplots(1, 3,
kwargs_("figsize"_a = py::make_tuple(9, 3),
"subplot_kw"_a = py::dict("aspect"_a = "equal")));
auto ax1 = axes[0], ax2 = axes[1], ax3 = axes[2];gallery folder contains corresponding examples from the official website of matplotlib with the same structure.
Contributions to this project are welcome if you could add or want/need more modules :)