Summary

I encountered some unexpected behavior while usingn matplotlib.colormaps. Apparently, a_colormap(1) outputs the wrong result. The color it produces is indistinguishable from a_colormap(0), although it is slightly different. a_colormap(1.0) produces the correct result, but a_colormap(1.0) != a_colormap(1).

What is going on? It would be useful to clarify this in the docs.

Example

from matplotlib import colors, colormaps
import matplotlib.pyplot as plt

print(colors.to_hex(colormaps["binary"](0)), colors.to_hex(colormaps["binary"](1.0)))
print(colors.to_hex(colormaps["binary"](0)), colors.to_hex(colormaps["binary"](1)))

Output

#ffffff #000000
#ffffff #fefefe

Proposed fix

Improved documentation, or added consistency to make integer values work for the upper endpoint.