add imshow

Cryoris · Cryoris · commit ed2c5c34fd5e · 2019-11-26T10:45:33.000+01:00
diff --git a/examples/CMakeLists.txt b/examples/CMakeLists.txt
@@ -21,6 +21,7 @@ add_example(eigen)
 add_example(errorbar)
 add_example(fill_inbetween)
 add_example(fill)
+add_example(imshow)
 add_example(legend)
 add_example(loglog)
 add_example(minimal)
diff --git a/examples/imshow.cpp b/examples/imshow.cpp
@@ -0,0 +1,22 @@
+#define __USE_MATH_DEFINES
+#include <cmath>
+#include <Eigen/Dense>
+#include "../matplotlibcpp.h"
+namespace plt = matplotlibcpp;
+
+void waves(const unsigned n) {
+  Eigen::MatrixXd X(n, n);
+  for (unsigned i = 0; i < n; ++i) {
+    for (unsigned j = 0; j < n; ++j) {
+      X(i, j) = sin(3.0 * M_PI * i / n) * cos(20.0 * M_PI * j / n);
+    }
+  }
+  plt::figure();
+  plt::imshow(X);
+  plt::show();
+}
+
+int main() {
+  waves(200);
+  return 0;
+}
diff --git a/matplotlibcpp.h b/matplotlibcpp.h
@@ -92,6 +92,7 @@ struct _interpreter {
   PyObject *s_python_function_suptitle;
   PyObject *s_python_function_bar;
   PyObject *s_python_function_subplots_adjust;
+  PyObject *s_python_function_imshow;
 
   /* For now, _interpreter is implemented as a singleton since its currently not
      possible to have multiple independent embedded python interpreters without
@@ -226,6 +227,7 @@ struct _interpreter {
     s_python_function_bar = PyObject_GetAttrString(pymod, "bar");
     s_python_function_subplots_adjust =
         PyObject_GetAttrString(pymod, "subplots_adjust");
+    s_python_function_imshow = PyObject_GetAttrString(pymod, "imshow");
 
     if (!s_python_function_show || !s_python_function_close ||
         !s_python_function_draw || !s_python_function_pause ||
@@ -248,7 +250,7 @@ struct _interpreter {
         !s_python_function_stem || !s_python_function_xkcd ||
         !s_python_function_text || !s_python_function_suptitle ||
         !s_python_function_bar || !s_python_function_subplots_adjust ||
-        !s_python_function_spy) {
+        !s_python_function_spy || !s_python_function_imshow) {
       throw std::runtime_error("Couldn't find required function!");
     }
 
@@ -292,7 +294,9 @@ struct _interpreter {
         !PyFunction_Check(s_python_function_text) ||
         !PyFunction_Check(s_python_function_suptitle) ||
         !PyFunction_Check(s_python_function_bar) ||
-        !PyFunction_Check(s_python_function_subplots_adjust)) {
+        !PyFunction_Check(s_python_function_subplots_adjust) ||
+        !PyFunction_Check(s_python_function_imshow)
+      ) {
       throw std::runtime_error(
           "Python object is unexpectedly not a PyFunction.");
     }
@@ -660,6 +664,29 @@ bool semilogy(const VectorY &y,
   return semilogy(x, y, "", keywords);
 }
 
+template <typename Matrix>
+void imshow(const Matrix& X, const std::map<std::string, std::string> &keywords = {}) {
+  PyObject *Xarray = get_2darray(X);
+
+  PyObject *kwargs = PyDict_New();
+  for (std::map<std::string, std::string>::const_iterator it = keywords.begin();
+       it != keywords.end(); ++it) {
+    PyDict_SetItemString(kwargs, it->first.c_str(),
+                         PyUnicode_FromString(it->second.c_str()));
+  }
+
+  PyObject *plot_args = PyTuple_New(1);
+  PyTuple_SetItem(plot_args, 0, Xarray);
+
+  PyObject *res = PyObject_Call(
+      detail::_interpreter::get().s_python_function_imshow, plot_args, kwargs);
+
+  Py_DECREF(plot_args);
+  Py_DECREF(kwargs);
+  if (res)
+    Py_DECREF(res);
+}
+
 // @brief plot_surface for datapoints (x_ij, y_ij, z_ij) with i,j = 0..n
 // @param x The x values of the datapoints in a matrix
 // @param y The y values of the datapoints in a matrix
