Creating colorbar without artist fails with LogNorm #13967
Description
#13171 documented how to create a colobar that is not associated with an artist. This recipe fails when the colorbar norm is a LogNorm however:
import matplotlib.pyplot as plt
import matplotlib.cm as cm
import matplotlib.colors as mcolor
fig, ax = plt.subplots()
sm = cm.ScalarMappable(norm=mcolor.LogNorm(), cmap='viridis')
fig.colorbar(sm)
plt.draw()gives
Traceback (most recent call last):
File "test.py", line 7, in <module>
fig.colorbar(sm)
File "/Users/dstansby/github/matplotlib/lib/matplotlib/figure.py", line 2208, in colorbar
cb = cbar.colorbar_factory(cax, mappable, **cb_kw)
File "/Users/dstansby/github/matplotlib/lib/matplotlib/colorbar.py", line 1641, in colorbar_factory
cb = Colorbar(cax, mappable, **kwargs)
File "/Users/dstansby/github/matplotlib/lib/matplotlib/colorbar.py", line 1183, in __init__
ColorbarBase.__init__(self, ax, **kw)
File "/Users/dstansby/github/matplotlib/lib/matplotlib/colorbar.py", line 460, in __init__
self.draw_all()
File "/Users/dstansby/github/matplotlib/lib/matplotlib/colorbar.py", line 483, in draw_all
self._process_values()
File "/Users/dstansby/github/matplotlib/lib/matplotlib/colorbar.py", line 932, in _process_values
b = self.norm.inverse(self._uniform_y(self.cmap.N + 1))
File "/Users/dstansby/github/matplotlib/lib/matplotlib/colors.py", line 1085, in inverse
return vmin * np.ma.power((vmax / vmin), val)
ZeroDivisionError: division by zeroChanging LogNorm to Normalize makes the example work fine again, as intended.