python - Having line color vary with data index for line graph in matplotlib?

Question

So I have a 2D array of data producing a plot of many timeseries on the same axes. At the moment, the colour of each line just cycles through and doesn't mean anything.

I want to somehow map the colour of each line to the index of its data - so a set of data with a low index appears red and then fades to blue at a high index.

To clarify, each individual line should be the same colour throughout, not fading with time. The difference should be between each line.

Thankyou!

Answer 1

Often you pass a colormap to a plotting function, but you can also pass a number or array to a colormap and get the colors in return.

So to color each line according to a variable, do something like this:

numlines = 20

for i in np.linspace(0,1, numlines):
    plt.plot(np.arange(numlines),np.tile([i],numlines), linewidth=4, color=plt.cm.RdYlBu(i))