Setting range of a colormap in Matplotlib

问题:

I'm using matplotlib to plot a simple graph:

cm=plt.get_cmap('Blues')

nx.draw_circular(G,
        node_color='White',
        edge_color=range(G.number_of_edges()),
        edge_cmap=cm,
        node_size=900,
        width=4
        )

I want to set a range on the colormap 'Blues' in such a way to delete the white color which is not visible in the draw.

Please help!

Sorry for bad english.

回答1:

The range (or normilization) is not really a feature of the colormap, but is often implemented as a feature in the functions that plot using colormaps. For example, imshow uses vmin and vmax, so you might try using these as keywords with draw_circular (I can't find the documentation), or maybe norm.

Other than this, you can make your own colormap with exact color arrangement that you want. There are plenty of examples on how to make custom colormaps, and a few different approaches available. Here (a, b, c, d) are a few examples that might be useful to you.