Matplotlib colormap plotting (specified/all)

gistfile1.py

import numpy as np
import matplotlib.pyplot as plt

a = np.linspace(0, 1, 256).reshape(1,-1)
a = np.vstack((a,a))

plot_spec = None

if plot_spec is None:
  # Get a list of the colormaps in matplotlib.  Ignore the ones that end with
  # '_r' because these are simply reversed versions of ones that don't end
  # with '_r'
  maps = sorted(m for m in plt.cm.datad if not m.endswith("_r"))
  nmaps = len(maps) + 1

  fig = plt.figure(figsize=(5,10))
  fig.subplots_adjust(top=0.99, bottom=0.01, left=0.2, right=0.99)
  for i,m in enumerate(maps):
      ax = plt.subplot(nmaps, 1, i+1)
      plt.axis("off")
      plt.imshow(a, aspect='auto', cmap=plt.get_cmap(m), origin='lower')
      pos = list(ax.get_position().bounds)
      fig.text(pos[0] - 0.01, pos[1], m, fontsize=10, horizontalalignment='right')
else:
  fig = plt.figure(figsize=(5,5))
  plt.axis('off')
  plt.imshow(a, aspect='auto', cmap=plt.get_cmap(plot_spec))
  fig.text(0.5, 0.95, plot_spec, fontsize=10, verticalalignment='center',
           horizontalalignment='center')

plt.show()