(Source code, png, pdf)
"""
Demo of the `streamplot` function.
A streamplot, or streamline plot, is used to display 2D vector fields. This
example shows a few features of the stream plot function:
* Varying the color along a streamline.
* Varying the density of streamlines.
* Varying the line width along a stream line.
"""
import numpy as np
import matplotlib.pyplot as plt
X, Y = (np.linspace(-3, 3, 100),
np.linspace(-3, 3, 100))
U, V = np.mgrid[-3:3:100j, 0:0:100j]
seed_points = np.array([[-2, 0, 1], [-2, 0, 1]])
fig0, ax0 = plt.subplots()
strm = ax0.streamplot(X, Y, U, V, color=U, linewidth=2,
cmap=plt.cm.autumn, start_points=seed_points.T)
fig0.colorbar(strm.lines)
ax0.plot(seed_points[0], seed_points[1], 'bo')
ax0.axis((-3, 3, -3, 3))
plt.show()
Keywords: python, matplotlib, pylab, example, codex (see Search examples)