Some example data for testing colormaps.

hist2d.txt:

  A 2d histogram of samples from a probability model. (Specifically,
  it's Eposterior-flat-S-40 from
  praglearn/praglearn/figures/Eposterior.py. The previous sentence
  won't make any sense unless you are Nathaniel, and that's ok.)

st-helens_before-modified.txt.gz:

  Heightmap of Mt. St. Helens, taken from
     https://github.com/agile-geoscience/notebooks/blob/master/data/st-helens_before.txt
  So Apache 2.0 licensed, I guess. See
    http://nbviewer.ipython.org/github/agile-geoscience/notebooks/blob/master/Mt_St-Helens.ipynb
  for example using it.

  This copy is modified from the version linked above -- it has had
  all -32767 values replaced by NaNs.
