Cubehelix Colormap for Python

I have been transitioning to using Python for more and more of my research, which has gone relatively smoothly I'm happy to say! Within the last ~2 years Python's libraries and documentation for things astronomical has reached a "critical mass", and making the transition for most things has never been easier!

However, one little problem still eats at my soul every day I use Python, specifically Matplotlib: the colors in figures are usually terrible!

My absolute favorite color map (at least for now) is cubehelix. I have written about this color map before:
CUBEHELIX, or How I Learn to Love Black & White Printers,
I also wrote the version for IDL used in the Coyote Library, and helped bring a version to the Tableau community last year.

A real cubehelix version for Python

Matplotlib already has the default cubehelix colormap built in, as well as several excellent colormaps that properly desaturate. What makes the cubehelix algorithm so powerful is that it defines a family of colormaps that all desaturate properly. This is what is missing currently in Matplotlib.

The Python community has a strong "put up or shut up" attitude that I love, so I spent a few hours translating my IDL implementation of cubehelix in to Python!

The code is available on github. 
Try it out, it's dead simple to use!

Some Examples

import numpy as np

import matplotlib.pyplot as plt

import cubehelix 

# set up some simple data to plot

x = np.random.randn(10000)

y = np.random.randn(10000)

# create the default "cubehelix" colormap

cx1 = cubehelix.cmap()

plt.hexbin(x,y,gridsize=50,cmap=cx1)

plt.colorbar()
plt.show()

# Reverse of the default "cubehelix" colormap

# I think this is more appropriate for density maps, 

# as intensity corresponds with density.

cx2 = cubehelix.cmap(reverse=True)

plt.hexbin(x,y,gridsize=50,cmap=cx2)

plt.colorbar()

plt.show()

# My favorite flavor of "cubehelix", 

# mostly blue with a small hue change

cx3 = cubehelix.cmap(reverse=True, start=0.3, rot=-0.5)

plt.hexbin(x,y,gridsize=50,cmap=cx3)

plt.colorbar()

plt.show()

# Another good version, mostly using red/purples

cx4 = cubehelix.cmap(reverse=True, start=0., rot=0.5)

plt.hexbin(x,y,gridsize=50,cmap=cx4)

plt.colorbar()

plt.show() 

update:
Apparently I've just reinvented the cubehelix wheel! I can live with that

@treycausey This actually already exists in matplotlib, but the custom creation of a cubehelix map is weirdly hidden at mpl._cm.cubehelix
— Michael Waskom (@michaelwaskom) April 16, 2014

update 2:
The creator of D3, Mike Bostock, has made a version available for that language as well. So that's it, people. No more excuses to not use this awesome color scheme! (GitHub README)