CoCalc Public Filestmp / 2014-10-26-212344.sagews
Authors: Harald Schilly, ℏal Snyder, William A. Stein
"""
Demo of scatter plot on a polar axis.

Size increases radially in this example and color increases with angle (just to
verify the symbols are being scattered correctly).
"""
import numpy as np
import matplotlib.pyplot as plt

N = 150
r = 2 * np.random.rand(N)
theta = 2 * np.pi * np.random.rand(N)
area = 200 * r**2 * np.random.rand(N)
colors = theta

ax = plt.subplot(111, polar=True)
c = plt.scatter(theta, r, c=colors, s=area, cmap=plt.cm.hsv)
c.set_alpha(0.75)

plt.show()

'\nDemo of scatter plot on a polar axis.\n\nSize increases radially in this example and color increases with angle (just to\nverify the symbols are being scattered correctly).\n'
import numpy as np
import matplotlib.pyplot as plt
from mpl_toolkits.mplot3d import Axes3D
import matplotlib.tri as mtri

# u, v are parameterisation variables
u = (np.linspace(0, 2.0 * np.pi, endpoint=True, num=50) * np.ones((10, 1))).flatten()
v = np.repeat(np.linspace(-0.5, 0.5, endpoint=True, num=10), repeats=50).flatten()

# This is the Mobius mapping, taking a u, v pair and returning an x, y, z
# triple
x = (1 + 0.5 * v * np.cos(u / 2.0)) * np.cos(u)
y = (1 + 0.5 * v * np.cos(u / 2.0)) * np.sin(u)
z = 0.5 * v * np.sin(u / 2.0)

# Triangulate parameter space to determine the triangles
tri = mtri.Triangulation(u, v)

fig = plt.figure()
ax = fig.add_subplot(1, 1, 1, projection='3d')

# The triangles in parameter space determine which x, y, z points are
# connected by an edge
ax.plot_trisurf(x, y, z, triangles=tri.triangles, cmap=plt.cm.Spectral)

ax.set_zlim(-1, 1)

# First create the x and y coordinates of the points.
n_angles = 36

angles = np.linspace(0, 2*np.pi, n_angles, endpoint=False)
angles[:,1::2] += np.pi/n_angles

# Create the Triangulation; no triangles so Delaunay triangulation created.
triang = mtri.Triangulation(x, y)

xmid = x[triang.triangles].mean(axis=1)
ymid = y[triang.triangles].mean(axis=1)

# tripcolor plot.
fig = plt.figure()
ax = fig.add_subplot(1, 1, 1, projection='3d')
ax.plot_trisurf(triang, z, cmap=plt.cm.CMRmap)
plt.show()

<mpl_toolkits.mplot3d.art3d.Poly3DCollection object at 0x7fa0d1f29d50> (-1, 1) <mpl_toolkits.mplot3d.art3d.Poly3DCollection object at 0x7fa0d1ea1f10>