Add plot to docstring

Author: AntSimi

doc/conf.py

@@ -36,6 +36,8 @@
     "sphinx.ext.intersphinx",
     "sphinx.ext.viewcode",
     "sphinx_gallery.gen_gallery",
+    "matplotlib.sphinxext.plot_directive",
+
 ]
 
 autoclass_content = 'both'

src/py_eddy_tracker/generic.py

@@ -38,6 +38,7 @@
     isnan,
     bool_,
     concatenate,
+    radians,
 )
 from numba import njit, prange, types as numba_types
 from .poly import winding_number_grid_in_poly
@@ -497,3 +498,18 @@ def get_pixel_in_regular(vertices, x_c, y_c, x_start, x_stop, y_start, y_stop):
             y_start,
             vertices,
         )
+
+
+def build_circle(x0, y0, r):
+    """
+    Method to built circle from center coordinates
+
+    :param float x0: center coordinate
+    :param float y0: center coordinate
+    :param float r: radius i meter
+    :return: x,y
+    :rtype: (array,array)
+    """
+    angle = radians(linspace(0, 360, 50))
+    x_norm, y_norm = cos(angle), sin(angle)
+    return x_norm * r + x0, y_norm * r + y0

src/py_eddy_tracker/poly.py

@@ -382,8 +382,24 @@ def fit_circle_(x, y):
     :param array y: y of polygon
     :return: x0, y0, radius, shape_error
     :rtype: (float,float,float,float)
+
+    .. plot::
+
+        import matplotlib.pyplot as plt
+        import numpy as np
+        from py_eddy_tracker.poly import fit_circle_
+        from py_eddy_tracker.generic import build_circle
+        V = np.array(((2, 2, 3, 3, 2), (-10, -9, -9, -10, -10)), dtype='f4')
+        x0, y0, radius, err = fit_circle_(V[0], V[1])
+        ax = plt.subplot(111)
+        ax.set_aspect('equal')
+        ax.grid(True)
+        ax.plot(*build_circle(x0,y0, radius), 'r')
+        ax.plot(x0, y0, 'r+')
+        ax.plot(*V, 'b.')
+        plt.show()
     """
-    datas = ones((x.shape[0] - 1, 3))
+    datas = ones((x.shape[0] - 1, 3), dtype=x.dtype)
     # we skip first position which are the same than the last
     datas[:, 0] = x[1:]
     datas[:, 1] = y[1:]