1"""
2==================
3Ellipse With Units
4==================
5
6Compare the ellipse generated with arcs versus a polygonal approximation
7
8.. only:: builder_html
9
10   This example requires :download:`basic_units.py <basic_units.py>`
11"""
12from basic_units import cm
13import numpy as np
14from matplotlib import patches
15import matplotlib.pyplot as plt
16
17
18xcenter, ycenter = 0.38*cm, 0.52*cm
19width, height = 1e-1*cm, 3e-1*cm
20angle = -30
21
22theta = np.deg2rad(np.arange(0.0, 360.0, 1.0))
23x = 0.5 * width * np.cos(theta)
24y = 0.5 * height * np.sin(theta)
25
26rtheta = np.radians(angle)
27R = np.array([
28    [np.cos(rtheta), -np.sin(rtheta)],
29    [np.sin(rtheta),  np.cos(rtheta)],
30    ])
31
32
33x, y = np.dot(R, np.array([x, y]))
34x += xcenter
35y += ycenter
36
37###############################################################################
38
39fig = plt.figure()
40ax = fig.add_subplot(211, aspect='auto')
41ax.fill(x, y, alpha=0.2, facecolor='yellow',
42        edgecolor='yellow', linewidth=1, zorder=1)
43
44e1 = patches.Ellipse((xcenter, ycenter), width, height,
45                     angle=angle, linewidth=2, fill=False, zorder=2)
46
47ax.add_patch(e1)
48
49ax = fig.add_subplot(212, aspect='equal')
50ax.fill(x, y, alpha=0.2, facecolor='green', edgecolor='green', zorder=1)
51e2 = patches.Ellipse((xcenter, ycenter), width, height,
52                     angle=angle, linewidth=2, fill=False, zorder=2)
53
54
55ax.add_patch(e2)
56fig.savefig('ellipse_compare')
57
58###############################################################################
59
60fig = plt.figure()
61ax = fig.add_subplot(211, aspect='auto')
62ax.fill(x, y, alpha=0.2, facecolor='yellow',
63        edgecolor='yellow', linewidth=1, zorder=1)
64
65e1 = patches.Arc((xcenter, ycenter), width, height,
66                 angle=angle, linewidth=2, fill=False, zorder=2)
67
68ax.add_patch(e1)
69
70ax = fig.add_subplot(212, aspect='equal')
71ax.fill(x, y, alpha=0.2, facecolor='green', edgecolor='green', zorder=1)
72e2 = patches.Arc((xcenter, ycenter), width, height,
73                 angle=angle, linewidth=2, fill=False, zorder=2)
74
75
76ax.add_patch(e2)
77fig.savefig('arc_compare')
78
79plt.show()
80