I have a series of lines that each need to be plotted with a separate colour. Each line is actually made up of several data sets (positive, negative regions etc.) and so I'd like to be able to create a generator that will feed one colour at a time across a spectrum, for example the
gist_rainbow map shown here.
I have found the following works but it seems very complicated and more importantly difficult to remember,
from pylab import * NUM_COLORS = 22 mp = cm.datad['gist_rainbow'] get_color = matplotlib.colors.LinearSegmentedColormap.from_list(mp, colors=['r', 'b'], N=NUM_COLORS) ... # Then in a for loop this_color = get_color(float(i)/NUM_COLORS)
Moreover, it does not cover the range of colours in the
gist_rainbow map, I have to redefine a map.
Maybe a generator is not the best way to do this, if so what is the accepted way?
To index colors from a specific colormap you can use:
import pylab NUM_COLORS = 22 cm = pylab.get_cmap('gist_rainbow') for i in range(NUM_COLORS): color = cm(1.*i/NUM_COLORS) # color will now be an RGBA tuple # or if you really want a generator: cgen = (cm(1.*i/NUM_COLORS) for i in range(NUM_COLORS))