#!/usr/bin/env python # -*- coding: utf-8 -*- # ############################################################################ # # MODULE: r.colors.cubehelix # AUTHOR: Vaclav Petras # PURPOSE: Convert a GMT color table into a GRASS color rules file # COPYRIGHT: (C) 2007 by Vaclav Petras, Anna Petrasova # and the GRASS Development Team # This program is free software under the GNU General Public # License (>=v2). Read the file COPYING that comes with GRASS # for details. # ############################################################################# #%module #% description: Create or apply a cubehelix color table to a GRASS raster map #% keyword: raster #% keyword: color table #% keyword: cubehelix #% keyword: seaborn #%end #%option G_OPT_R_MAPS #% description: Raster map(s) to apply color table to #% required: no #% guisection: Basic #%end #%option G_OPT_F_OUTPUT #% description: Name for the new color table rules file #% required: no #%end #%option #% key: start #% type: double #% description: The hue at the start of the helix #% options: 0-3 #% answer: 0 #% required: no #% guisection: Cubehelix #%end #%option #% key: nrotations #% type: double #% label: Rotations around the hue wheel #% description: Rotations around the hue wheel over the range of the color table #% options: 0-3 #% answer: 0.4 #% required: no #% guisection: Cubehelix #%end #%option #% key: gamma #% type: double #% description: Gamma factor to emphasize darker (<1) or lighter (>1) colors #% options: 0- #% answer: 1.0 #% required: no #% guisection: Cubehelix #%end #%option #% key: hue #% type: double #% description: Saturation of the colors #% options: 0-1 #% answer: 0.8 #% required: no #% guisection: Cubehelix #%end #%option #% key: light #% type: double #% description: Intensity of the lightest color in the color table #% options: 0-1 #% answer: 0.85 #% required: no #% guisection: Cubehelix #%end #%option #% key: dark #% type: double #% description: Intensity of the darkest color in the color table #% options: 0-1 #% answer: 0.15 #% required: no #% guisection: Cubehelix #%end #%option #% key: ncolors #% type: integer #% label: Number of colors in the color table #% description: Number of color intervals in a discrete color table with -d #% options: 2- #% answer: 6 #% required: no #% guisection: Rules #%end #%flag #% key: d #% label: Generate discrete color table #% description: Generate discrete (interval) color table instead of a continuous one #% guisection: Rules #%end #%flag #% key: n #% label: Reverse the order of colors (invert colors) #% description: If set, the color table will go from dark to light #% guisection: Basic #%end #%flag #% key: g #% description: Logarithmic scaling #% guisection: Basic #%end #%flag #% key: a #% description: Logarithmic-absolute scaling #% guisection: Basic #%end #%flag #% key: e #% description: Histogram equalization #% guisection: Basic #%end #%rules #% requires: -g, map #% requires: -a, map #% requires: -e, map #%end import os import sys import grass.script as gscript def values_to_rule(value, red, green, blue, percent): """Return textual representation of one color rule line""" return "{v:.3f}{p} {r}:{g}:{b}".format(v=value, p='%' if percent else '', r=red, g=green, b=blue) # sync with r.colors.matplotlib # this can potentially go to the core as something like grass.utils def mpl_cmap_to_rules(cmap, n_colors=None, discrete=False, comments=None): if not n_colors: n_colors = cmap.N # determine numbers for recomputing from absolute range to relative cmin = 0 cmax = n_colors if not discrete: cmax -= 1 crange = cmax - cmin cinterval = float(crange) / n_colors rules = [] if comments: for comment in comments: rules.append("# {}".format(comment)) for v1 in range(0, n_colors, 1): r1, g1, b1 = cmap(v1)[:3] if discrete: v2 = v1 + cinterval v1 = 100 * (crange - (cmax - v1)) / float(crange) if discrete: v2 = 100 * (crange - (cmax - v2)) / float(crange) # multiply to get 255 after integer # assuming nobody uses smaller faction than 0.001 # taken from color_rules.c r1 = int(r1 * 255.999) g1 = int(g1 * 255.999) b1 = int(b1 * 255.999) rules.append(values_to_rule(value=v1, red=r1, green=g1, blue=b1, percent=True)) if discrete: rules.append(values_to_rule(value=v2, red=r1, green=g1, blue=b1, percent=True)) return '\n'.join(rules) def main(options, flags): # TODO: inervals flag, s should be defaut behavior n_colors = int(options['ncolors']) discrete = flags['d'] fallback = True try: import seaborn as sns fallback = False except ImportError: # perhaps this can be function in the core gscript.error(_("{} Python package not installed.").format('seaborn')) if not fallback: cmap = sns.cubehelix_palette( n_colors=n_colors, start=float(options['start']), rot=float(options['nrotations']), gamma=float(options['gamma']), hue=float(options['hue']), light=float(options['light']), dark=float(options['dark']), reverse=flags['n'], as_cmap=False) # as_cmap ignores n_colors in 0.7.0 # but we want n_colors to be exact when we are exporting # the color table or doing discrete one import matplotlib.colors as clr cmap = clr.LinearSegmentedColormap.from_list('from_list', cmap, N=n_colors) else: gscript.warning(_("Using Matplotlib cubehelix color table." " Most of cubehelix parameters ignored")) # we are very nice and provide a fallback import matplotlib.pyplot as plt name = 'cubehelix' # Matplotlib one goes from dark to light but Seaborn goes # the other way around by default if not flags['n']: name += '_r' cmap = plt.get_cmap(name, lut=n_colors) comments = [] comments.append( "Cubehelix color table generated using:") command = [sys.argv[0].split(os.path.sep)[-1]] command.extend(sys.argv[1:]) comments.append( " {}".format(' '.join(command))) rules = mpl_cmap_to_rules(cmap, n_colors=n_colors, discrete=discrete, comments=comments) if options['map']: rcf = '' for char in 'gae': if flags[char]: rcf += char gscript.write_command('r.colors', map=options['map'], flags=rcf, rules='-', stdin=rules,) if options['output']: with open(options['output'], 'w') as f: f.write(rules) f.write('\n') elif not options['map']: print(rules) if __name__ == '__main__': sys.exit(main(*gscript.parser()))