import sys
from pylab import *
import numpy
from matplotlib.cm import get_cmap
from matplotlib.colors import LinearSegmentedColormap,Normalize


data = numpy.linspace(-1.0,1.0,256).reshape(16,16)

norm = Normalize(vmin=0.0)

cmap256 = get_cmap('hot',lut=256)
cmap256.set_under('grey')
cmap16 = get_cmap('hot',lut=16)
cmap16.set_under('grey')


fig, [ax1,ax2] = plt.subplots(2)
ax1.set_aspect(1.0)
ax2.set_aspect(1.0)

ax1.pcolor(data,cmap=cmap256,norm=norm)
ax2.pcolor(data,cmap=cmap16,norm=norm)
#ax2.pcolor(data,cmap=cmap16,norm=norm)

fig.savefig('cmap_bug.png')

norm16 = norm(data)*16.0
print sum(norm16<0)
print sum(norm16.astype(int)<0)

norm256 = norm(data)*256.0
print sum(norm256<0)
print sum(norm256.astype(int)<0)