Set radial axis on Matplotlib polar plots

Question

I'm plotting an azimuth-elevation curve on a polar plot where the elevation is the radial component. By default, Matplotlib plots the radial value from 0 in the center to 90 on the perimeter. I want to reverse that so 90 degrees is at the center. I tried setting the limits with a call to ax.set_ylim(90,0) but this results in a LinAlgError exception being thrown. ax is the axes object obtained from a call to add_axes. Can this be done and, if so, what must I do? Edit: Here is what I'm using now. The basic plotting code was taken from one of the Matplotlib examples ``` # radar green, solid grid lines rc('grid', color='#316931', linewidth=1, linestyle='-') rc('xtick', labelsize=10) rc('ytick', labelsize=10) # force square figure and square axes looks better for polar, IMO width, height = matplotlib.rcParams['figure.figsize'] size = min(width, height) # make a square figure fig = figure(figsize=(size, size)) ax = fig.add_axes([0.1, 0.1, 0.8, 0.8], projection='polar', axisbg='#d5de9c') # A…

Accepted Answer

I managed to put he radial axis inverted. I had to remap the radius, in order to match the new axis:

```
fig = figure()
ax = fig.add_subplot(1, 1, 1, polar=True)

def mapr(r):
   """Remap the radial axis."""
   return 90 - r

r = np.arange(0, 90, 0.01)
theta = 2 * np.pi * r / 90

ax.plot(theta, mapr(r))
ax.set_yticks(range(0, 90, 10))                   # Define the yticks
ax.set_yticklabels(map(str, range(90, 0, -10)))   # Change the labels
```

Note that is just a hack, the axis is still with the 0 in the center and 90 in the perimeter. You will have to use the mapping function for all the variables that you are plotting.

Set radial axis on Matplotlib polar plots

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