../../../_images/plot_quiver_1.png

Python source code: plot_quiver.py

import numpy as np
n = 8
X, Y = np.mgrid[0:n, 0:n]
T = np.arctan2(Y - n/ 2., X - n / 2.)
R = 10 + np.sqrt((Y - n / 2.) ** 2 + (X - n / 2.) ** 2)
U, V = R * np.cos(T), R * np.sin(T)
pl.quiver(X, Y, U, V, R, alpha=.5)
pl.quiver(X, Y, U, V, edgecolor='k', facecolor='None', linewidth=.5)
pl.xlim(-1, n)
pl.xticks(())
pl.ylim(-1, n)
pl.yticks(())
pl.text(-0.05, 1.02, " Quiver Plot: pl.quiver(...)\n",
horizontalalignment='left',
verticalalignment='top',
size='xx-large',
bbox=dict(facecolor='white', alpha=1.0, width=400, height=65),
transform=pl.gca().transAxes)
pl.text(-0.05, 1.01, "\n\n Plot a 2-D field of arrows ",
horizontalalignment='left',
verticalalignment='top',
size='large',
transform=pl.gca().transAxes)
pl.show()