Re: [Matplotlib-users] defining a custom RGB colormap

Paul,

Thanks for the detailed tutorial. I'm getting errors when I attempt to use plt.subplots(1,1) and the newcm assignment.

Traceback (most recent call last):
  File "colorbar_Mytest2.py", line 17, in <module>
    f, ax = plt.subplots(1,1)
AttributeError: 'module' object has no attribute 'subplots'


Here are just a few of the errors I'm getting when executing colorbar command with newcm. Also, what does In and Out do, as in Out[68]: 0.34999999999999998 ?

    plt.draw()
  File "/usr/lib/pymodules/python2.6/matplotlib/pyplot.py", line 352, in draw
    get_current_fig_manager().canvas.draw()
  File "/usr/lib/pymodules/python2.6/matplotlib/backends/backend_tkagg.py", line 215, in draw
    FigureCanvasAgg.draw(self)
  File "/usr/lib/pymodules/python2.6/matplotlib/backends/backend_agg.py", line 314, in draw
    self.figure.draw(self.renderer)
  File "/usr/lib/pymodules/python2.6/matplotlib/artist.py", line 46, in draw_wrapper
    draw(artist, renderer, *kl)
  File "/usr/lib/pymodules/python2.6/matplotlib/figure.py", line 773, in draw
    for a in self.axes: a.draw(renderer)
  File "/usr/lib/pymodules/python2.6/matplotlib/artist.py", line 46, in draw_wrapper


Here's a simplified version that works for me:


from matplotlib import pyplot, mpl
import sys,getopt
from mpl_toolkits.basemap import Basemap, shiftgrid, cm 
#from netCDF3 import Dataset as NetCDFFile 
from mpl_toolkits.basemap import  NetCDFFile
from pylab import *

vals = norm(np.linspace(14,40,1000))
newcm = cm.colors.ListedColormap(cm.hot_r(vals))

# Make a figure and axes with dimensions as desired.
fig = pyplot.figure(figsize=(8,3))
#f, ax = plt.subplots(1,1)
ax1 = fig.add_axes([0.05, 0.4, 0.9, 0.14])
#ax2 = fig.add_axes([0.05, 0.8, 0.9, 0.6])

# Set the colormap and norm to correspond to the data for which
# the colorbar will be used.
cmap = mpl.cm.cool
norm = mpl.colors.Normalize(vmin=0, vmax=40)   # here set colorbar min/max

mycolormap=cm.hot
maprev = cm.hot_r

#f,(ax2,ax3) = plt.subplots(2,1)
cb2 = mpl.colorbar.ColorbarBase(ax1, cmap=cm.hot_r,
                                     norm=norm,
                                     orientation='horizontal')

#cb2.set_label('"percent"')
#cb3 = mpl.colorbar.ColorbarBase(ax1, cmap=newcm,
#                                     orientation='horizontal')

#cb3.set_label("colormap interval 0.0-1.0")

plt.draw()