I'm plotting some hydrodynamical simulation data run in spherical coordinates and sometimes prefer to use contourf over pcolormesh because it looks nice and smooth instead of pixelated. However, I notice that contourf always extends my data to r=0 in a polar plot, yet my data never includes r=0. I have reproduced this issue with the simple example below:
from pylab import *
fig = figure(figsize=(6, 6))
ax = fig.add_subplot(111,projection='polar')
# generate some data
Nt,Nr = 150,150
r_axis = np.linspace(0.5,1.,Nr)
t_axis = np.linspace(0.,0.5*np.pi,Nt)
r_grid, t_grid = np.meshgrid(r_axis,t_axis)
data = np.zeros((Nt,Nr))
sin_theta = np.sin(t_axis)
for i in range(Nr):
data[:,i] = sin_theta
if 1: # polar plot using contourf - plots incorrectly from r = 0
scale = np.linspace(0.,1.,100)
polar = ax.contourf(t_grid,r_grid,data,scale,cmap='Spectral')
else: # correctly plots the data
polar = ax.pcolormesh(t_grid,r_grid,data,cmap='Spectral')
show()
Is there a quick fix? Thanks
