Using a colormap for matplotlib line plots

Question

I’d like to employ the reverse Spectral colormap ,

https://matplotlib.org/examples/color/colormaps_reference.html

for a lineplot.

This works fine with a hex bin plot::

color_map = plt.cm.Spectral_r
image = plt.hexbin(x,y,cmap=color_map)

but when I do

ax1.plot(x,y, cmp=color_map)

this gives me::

AttributeError: Unknown property cmap

Note, I just want to set the colormap and let matplotliob do the rest; i.e. I don't want to have a color=' argument in the .plot command.

Answer 1

You can have a look at this solution - the third variant is what you want:

https://stackoverflow.com/a/57227821/5972778

You need to know how many lines you're plotting in advance, as otherwise it doesn't know how to choose the colours from the range.

Answer 2

I think that seaborn's color_palette function is very convenient for this purpose. It can be used in a with statement to temporarily set the color cycle for a plot or set of plots. For example:

import matplotlib.pyplot as plt
import numpy as np
import seaborn as sns

with sns.color_palette("Spectral", n_colors=10):
    plt.plot(np.random.rand(5, 10))

You can use with any predefined matplotlib or seaborn colormap, or provide a custom sequence of colors.