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CryorisCryoris
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add contour plot, add support for keywords in scatter
1 parent bd05374 commit b568e87

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4 files changed

+131
-3
lines changed

4 files changed

+131
-3
lines changed

‎examples/CMakeLists.txt

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Original file line numberDiff line numberDiff line change
@@ -16,6 +16,7 @@ endfunction(add_example)
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add_example(axlines)
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add_example(bar)
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add_example(basic)
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add_example(contour)
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add_example(eigen)
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add_example(errorbar)
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add_example(fill_inbetween)
@@ -26,6 +27,7 @@ add_example(minimal)
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add_example(modern)
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add_example(nonblock)
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add_example(quiver)
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add_example(scatter)
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add_example(semilogx)
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add_example(semilogy)
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add_example(small)

‎examples/contour.cpp

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@@ -0,0 +1,35 @@
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#include <Eigen/Dense>
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#include "../matplotlibcpp.h"
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namespace plt = matplotlibcpp;
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template <typename Vector>
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std::pair<Eigen::MatrixXd, Eigen::MatrixXd> meshgrid(const Vector& x, const Vector& y) {
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const unsigned m = x.size(), n = y.size();
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// todo fix type
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Eigen::MatrixXd X(m, n), Y(m, n);
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for (unsigned i = 0; i < m; ++i) {
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for (unsigned j = 0; j < n; ++ j) {
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X(i, j) = *(x.data() + i);
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Y(i, j) = *(y.data() + j);
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}
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}
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std::pair<Eigen::MatrixXd, Eigen::MatrixXd> res = std::make_pair(X, Y);
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return res;
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}
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void plot_contour() {
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const unsigned n = 100;
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Eigen::VectorXd x = Eigen::VectorXd::LinSpaced(n, 0, 1),
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y = Eigen::VectorXd::LinSpaced(n, 0, 1);
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std::pair<Eigen::MatrixXd, Eigen::MatrixXd> XY = meshgrid(x, y);
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Eigen::MatrixXd Z = XY.first + 2 * XY.second;
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27+
plt::contour(XY.first, XY.second, Z);
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plt::show();
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}
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int main() {
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plot_contour();
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return 0;
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}

‎examples/scatter.cpp

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@@ -0,0 +1,25 @@
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#define _USE_MATH_DEFINES
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#include <cmath>
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#include <vector>
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#include "../matplotlibcpp.h"
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namespace plt = matplotlibcpp;
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void plot() {
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const unsigned n = 100;
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std::vector<double> x(n), y(n);
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#include <iostream>
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for (unsigned i = 0; i < n; ++i) {
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x[i] = sin(2 * M_PI * i / n);
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y[i] = cos(2 * M_PI * i / n);
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}
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plt::scatter(x, y, {{"color", "red"}, {"label", "a circle!"}});
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plt::legend();
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plt::show();
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}
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int main() {
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plot();
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return 0;
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}

‎matplotlibcpp.h

Lines changed: 69 additions & 3 deletions
Original file line numberDiff line numberDiff line change
@@ -53,6 +53,8 @@ struct _interpreter {
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PyObject *s_python_function_fignum_exists;
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PyObject *s_python_function_plot;
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PyObject *s_python_function_quiver;
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PyObject *s_python_function_contour;
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PyObject *s_python_function_colormap;
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PyObject *s_python_function_axhline;
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PyObject *s_python_function_axvline;
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PyObject *s_python_function_semilogx;
@@ -184,6 +186,7 @@ struct _interpreter {
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PyObject_GetAttrString(pymod, "fignum_exists");
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s_python_function_plot = PyObject_GetAttrString(pymod, "plot");
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s_python_function_quiver = PyObject_GetAttrString(pymod, "quiver");
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s_python_function_contour = PyObject_GetAttrString(pymod, "contour");
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s_python_function_axhline = PyObject_GetAttrString(pymod, "axhline");
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s_python_function_axvline = PyObject_GetAttrString(pymod, "axvline");
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s_python_function_semilogx = PyObject_GetAttrString(pymod, "semilogx");
@@ -228,6 +231,7 @@ struct _interpreter {
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!s_python_function_draw || !s_python_function_pause ||
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!s_python_function_figure || !s_python_function_fignum_exists ||
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!s_python_function_plot || !s_python_function_quiver ||
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!s_python_function_contour ||
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!s_python_function_semilogx || !s_python_function_semilogy ||
232236
!s_python_function_loglog || !s_python_function_fill ||
233237
!s_python_function_fill_between || !s_python_function_subplot ||
@@ -256,6 +260,7 @@ struct _interpreter {
256260
!PyFunction_Check(s_python_function_fignum_exists) ||
257261
!PyFunction_Check(s_python_function_plot) ||
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!PyFunction_Check(s_python_function_quiver) ||
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!PyFunction_Check(s_python_function_contour) ||
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!PyFunction_Check(s_python_function_semilogx) ||
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!PyFunction_Check(s_python_function_semilogy) ||
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!PyFunction_Check(s_python_function_loglog) ||
@@ -760,6 +765,53 @@ void plot_surface(const Matrix &x, const Matrix& y, const Matrix& z,
760765
Py_DECREF(res);
761766
}
762767

768+
769+
// @brief plot_surface for datapoints (x_ij, y_ij, z_ij) with i,j = 0..n
770+
// @param x The x values of the datapoints in a matrix
771+
// @param y The y values of the datapoints in a matrix
772+
// @param z The function value of the datapoints in a matrix
773+
// @param keywords Additional keywords
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template <typename Matrix>
775+
void contour(const Matrix &x, const Matrix& y, const Matrix& z,
776+
const std::map<std::string, std::string> &keywords = {}) {
777+
detail::_interpreter::get();
778+
779+
// using numpy arrays
780+
PyObject *xarray = get_2darray(x);
781+
PyObject *yarray = get_2darray(y);
782+
PyObject *zarray = get_2darray(z);
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784+
// construct positional args
785+
PyObject *args = PyTuple_New(3);
786+
PyTuple_SetItem(args, 0, xarray);
787+
PyTuple_SetItem(args, 1, yarray);
788+
PyTuple_SetItem(args, 2, zarray);
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790+
// Build up the kw args.
791+
PyObject *kwargs = PyDict_New();
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PyObject *python_colormap_coolwarm = PyObject_GetAttrString(
794+
detail::_interpreter::get().s_python_colormap, "coolwarm");
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796+
PyDict_SetItemString(kwargs, "cmap", python_colormap_coolwarm);
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for (std::map<std::string, std::string>::const_iterator it = keywords.begin();
799+
it != keywords.end(); ++it) {
800+
PyDict_SetItemString(kwargs, it->first.c_str(),
801+
PyString_FromString(it->second.c_str()));
802+
}
803+
804+
PyObject *res = PyObject_Call(detail::_interpreter::get().s_python_function_contour,
805+
args, kwargs);
806+
if (!res)
807+
throw std::runtime_error("failed surface");
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809+
Py_DECREF(args);
810+
Py_DECREF(kwargs);
811+
if (res)
812+
Py_DECREF(res);
813+
}
814+
763815
template <typename Numeric>
764816
bool stem(const std::vector<Numeric> &x, const std::vector<Numeric> &y,
765817
const std::map<std::string, std::string> &keywords) {
@@ -893,16 +945,23 @@ bool hist(const VectorY &y, long bins = 10, std::string color = "b",
893945
// @brief Scatter plot
894946
// @param x x-coordinates of the 2d points
895947
// @param y y-coordinates of the 2d points
896-
// @param s the marker size in points**2
948+
// @param s the marker size in points**2
949+
// @param keywords Additional keywords
897950
template <typename VectorX, typename VectorY>
898-
bool scatter(const VectorX &x, const VectorY &y, const double s = 1.0) {
951+
bool scatter(const VectorX &x, const VectorY &y, const double s = 1.0,
952+
const std::map<std::string, std::string> keywords = {}) {
899953
assert(x.size() == y.size());
900954

901955
PyObject *xarray = get_array(x);
902956
PyObject *yarray = get_array(y);
903957

904958
PyObject *kwargs = PyDict_New();
905-
PyDict_SetItemString(kwargs, "s", PyLong_FromLong(s));
959+
PyDict_SetItemString(kwargs, "s", PyFloat_FromDouble(s));
960+
for (std::map<std::string, std::string>::const_iterator it = keywords.begin();
961+
it != keywords.end(); ++it) {
962+
PyDict_SetItemString(kwargs, it->first.c_str(),
963+
PyUnicode_FromString(it->second.c_str()));
964+
}
906965

907966
PyObject *plot_args = PyTuple_New(2);
908967
PyTuple_SetItem(plot_args, 0, xarray);
@@ -919,6 +978,13 @@ bool scatter(const VectorX &x, const VectorY &y, const double s = 1.0) {
919978
return res;
920979
}
921980

981+
template <typename VectorX, typename VectorY>
982+
bool scatter(const VectorX &x, const VectorY &y,
983+
const std::map<std::string, std::string>& keywords) {
984+
return scatter(x, y, 1.0, keywords);
985+
}
986+
987+
922988
// @brief Spy plot
923989
// @param A the matrix
924990
// @param precision Plot all elements above `|precision|`

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