[ferret_users] For the end of the default rainbow palette !

[Patrick Brockmann <Patrick.Brockmann@xxxxxxxxxxxx>]

Hi ferreters,

I have found interesting the work that folks from matplotlib have done
about colormap (palette in the ferret vocabulary).

So attached a small python script to generate spectrum files for ferret (and pyferret).
I have found interesting the colormaps called Perceptually Uniform Sequential.
Perhaps that one of the 'viridis', 'inferno', 'plasma', 'magma' colormap
could be choosen to replace the default rainbow palette of ferret.





Note that matplotlib 1.5.0 is needed to get described colormaps.
See http://matplotlib.org/examples/color/colormaps_reference.html
and https://youtu.be/xAoljeRJ3lU - A Better Default Colormap for Matplotlib

Happy ferreting.

Patrick 

-- 
LSCE/IPSL, Laboratoire CEA-CNRS-UVSQ
Data Analysis and Visualization Engineer
ICMC - IPSL Climate Modelling Centre
--

#!/usr/bin/env python

import numpy as np
import matplotlib.pyplot as plt

# Have colormaps separated into categories:
# http://matplotlib.org/examples/color/colormaps_reference.html

cmaps = [('PSU',  # Perceptually Uniform Sequential'
                            ['viridis', 'inferno', 'plasma', 'magma']),
         ('Seq1', # Sequential
			    ['Blues', 'BuGn', 'BuPu',
                             'GnBu', 'Greens', 'Greys', 'Oranges', 'OrRd',
                             'PuBu', 'PuBuGn', 'PuRd', 'Purples', 'RdPu',
                             'Reds', 'YlGn', 'YlGnBu', 'YlOrBr', 'YlOrRd',
			     'afmhot', 'autumn', 'bone', 'cool',
                             'copper', 'gist_heat', 'gray', 'hot',
                             'pink', 'spring', 'summer', 'winter']),
         ('Div',  # Diverging
			     ['BrBG', 'bwr', 'coolwarm', 'PiYG', 'PRGn', 'PuOr',
                             'RdBu', 'RdGy', 'RdYlBu', 'RdYlGn', 'Spectral',
                             'seismic']),
         ('Qual', # Qualitative   
		             ['Accent', 'Dark2', 'Paired', 'Pastel1',
                             'Pastel2', 'Set1', 'Set2', 'Set3']),
         ('Misc', # Miscellaneous 
		             ['gist_earth', 'terrain', 'ocean', 'gist_stern',
                             'brg', 'CMRmap', 'cubehelix',
                             'gnuplot', 'gnuplot2', 'gist_ncar',
                             'nipy_spectral', 'jet', 'rainbow',
                             'gist_rainbow', 'hsv', 'flag', 'prism'])]

levels = 101

for cmap_category, cmap_list in cmaps:
    for cmap_name in cmap_list:
        print cmap_category+'_'+cmap_name

	for rev in '', '_r':

		cmap_name1 = cmap_name + rev
		file = open('mpl_' + cmap_category + "_" + cmap_name1 + ".spk", "w")

		cmap = plt.get_cmap(cmap_name1)
		colors = cmap(np.linspace(0, 1, levels))

		for i,c in enumerate(colors):
    			r,g,b,a = c
    			file.write("%f %f %f %f\n" %(i*100./(levels-1), r*100, g*100, b*100))

		file.close()