As it says in the title, I am trying to fix the values of the colorbar (vmin=-3 and vmax=+3) of a polar contour plot. I am going to generate several dozens of such graphs, and the auto scaling of the colorbar makes comparison very difficult.
The plot itself is generated by the following code:
fig, ax = subplots(subplot_kw=dict(projection='polar'))
cax = ax.contourf(thetas, r, values, 130)
cb1 = fig.colorbar(cax)
I have been going through http://matplotlib.sourceforge.org for hours and still haven't found the solution. I would point me in the right direction.
You can do this by passing in the contour levels yourself.
Instead of just trying to set vmin=3, vmax=3, pick 130 values between vmin and vmax so they will be the same for all the graphs, independent of the data range.
Try:
contour_levels = arange(-3, 3, 0.05)
fig, ax = subplots(subplot_kw=dict(projection='polar'))
cax = ax.contourf(thetas, r, values, contour_levels)
cb1 = fig.colorbar(cax)