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

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.

Answer 2

You can have a look at the top answer here - the third variant is what you want:

use matplotlib color map for color cycle

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.