matplotlib极性流图的范围错误

Question

I'm trying to plot streamlines in polar coordinates with matplotlib. However, some issues seem to appear on the ranges of the polar plot. Here is one short example to illustrate the problem:

import numpy as np
import matplotlib.pyplot as plt

r1 = np.linspace(0.5, 1, 50)
r2 = np.logspace(np.log10(0.5), np.log10(1.), 50)
t = np.linspace(0, 2*np.pi, 360)
r = r1

tt, rr = np.meshgrid(t, r)
v = 0*rr
u = rr

fig = plt.figure(figsize=(10,10))
ax = fig.add_subplot(1,1,1, projection='polar')
ax.streamplot(t, r, v, u, density=1., color='k', linewidth=3)
plt.show()
plt.close()

With r=r1 (linspace), there is no problem. But with r=r2 , the radial range of the plot is wrong and varies in [0.5, 0.82] instead of [0.5, 1.].

What is wrong with my code ?

Answer 1

From matplotlib.pyplot.streamplot 's doc , both x, y have to be evenly spaced. So you can interpolate your data using scipy's interpolants for instance. griddata might fit your needs.

[EDIT] This was solved in this SO question with interpolation.