minor fixes

doc/examples/plot_shapes.py

@@ -14,8 +14,10 @@ This example shows how to fill several different shapes:
 import numpy as np
 import matplotlib.pyplot as plt
 
-from skimage.draw import line, polygon, circle, circle_perimeter, ellipse
-
+from skimage.draw import line, polygon, circle, circle_perimeter, \
+                         ellipse, ellipse_perimeter, bezier_curve
+import numpy as np
+import math
 
 img = np.zeros((500, 500, 3), 'uint8')
 
@@ -43,8 +45,20 @@ rr, cc = ellipse(300, 300, 100, 200, img.shape)
 img[rr,cc,2] = 255
 
 # circle
-rr, cc = circle_perimeter(120, 400, 50)
+rr, cc = circle_perimeter(120, 400, 15)
+img[rr, cc, :] = (255, 0, 0)
+
+# ellipses
+rr, cc = ellipse_perimeter(120, 400, 60, 20, orientation=math.pi/4.)
 img[rr, cc, :] = (255, 0, 255)
+rr, cc = ellipse_perimeter(120, 400, 60, 20, orientation=-math.pi/4.)
+img[rr, cc, :] = (0, 0, 255)
+rr, cc = ellipse_perimeter(120, 400, 60, 20, orientation=math.pi/2.)
+img[rr, cc, :] = (255, 255, 255)
+
+# bezier curve
+rr, cc = bezier_curve(120, 400, 150, 480, 160, 400, weight=2)
+img[rr, cc, :] = (255, 255, 255)
 
 plt.imshow(img)
 plt.show()

skimage/draw/_draw.pyx

@@ -265,7 +265,7 @@ def circle_perimeter(Py_ssize_t cy, Py_ssize_t cx, Py_ssize_t radius,
 
 
 def ellipse_perimeter(Py_ssize_t cy, Py_ssize_t cx, Py_ssize_t yradius,
-                      Py_ssize_t xradius, double angle=0):
+                      Py_ssize_t xradius, double orientation=0):
     """Generate ellipse perimeter coordinates.
 
     Parameters
@@ -274,8 +274,8 @@ def ellipse_perimeter(Py_ssize_t cy, Py_ssize_t cx, Py_ssize_t yradius,
         Centre coordinate of ellipse.
     yradius, xradius: int
         Minor and major semi-axes. ``(x/xradius)**2 + (y/yradius)**2 = 1``.
-    angle: double, optional
-        Major axis angle (in radian).
+    orientation: double, optional
+        Major axis orientation in clockwise direction as radians.
 
     Returns
     -------
@@ -326,7 +326,7 @@ def ellipse_perimeter(Py_ssize_t cy, Py_ssize_t cx, Py_ssize_t yradius,
     cdef int ix0, ix1, iy0, iy1, ixd, iyd
     cdef double sin_angle, xa, ya, za, a, b
 
-    if angle == 0:
+    if orientation == 0:
         x = -xradius
         y = 0
         e2 = yd
@@ -360,7 +360,7 @@ def ellipse_perimeter(Py_ssize_t cy, Py_ssize_t cx, Py_ssize_t yradius,
             py.append(cy - y)
 
     else:
-        sin_angle = sin(angle)
+        sin_angle = sin(orientation)
         za = (xd - yd) * sin_angle
         xa = sqrt(xd - za * sin_angle)
         ya = sqrt(yd + za * sin_angle)
@@ -376,7 +376,7 @@ def ellipse_perimeter(Py_ssize_t cy, Py_ssize_t cx, Py_ssize_t yradius,
 
         xa = ix1 - ix0
         ya = iy1 - iy0
-        za = 4 * za * cos(angle)
+        za = 4 * za * cos(orientation)
         w = xa * ya
         if w != 0:
             w = (w - za) / (w + w)
@@ -414,6 +414,8 @@ def bezier_curve(Py_ssize_t x0, Py_ssize_t y0,
         Coordinates of the middle point
     x2, y2 : int
         Coordinates of the last point
+    weight : double
+        Middle point weight, it describes the line tension.
 
     Returns
     -------

skimage/draw/tests/test_draw.py

@@ -1,7 +1,8 @@
 from numpy.testing import assert_array_equal
 import numpy as np
 
-from skimage.draw import line, polygon, circle, circle_perimeter, ellipse, ellipse_perimeter, bezier_curve
+from skimage.draw import line, polygon, circle, circle_perimeter, \
+                         ellipse, ellipse_perimeter, bezier_curve
 
 
 def test_line_horizontal():