def register_brewer(cname='all', reverse=False, grey=False, gray=False):
'''Register colourmap(s) with Matplotlib
Ex.: register_brewer('ygn3')
'''
from matplotlib.colors import ListedColormap
from matplotlib.cm import register_cmap
from jams.color import rgb2rgb01
if cname.lower() == 'all':
cmaps = all_maps
elif cname.lower() == 'sequential':
cmaps = brewer_sequential
elif cname.lower() == 'diverging':
cmaps = brewer_diverging
elif cname.lower() == 'qualitative':
cmaps = brewer_qualitative
elif cname.lower() == 'osu':
cmaps = oregon
elif cname.lower() == 'ncl_large':
cmaps = ncl_large
elif cname.lower() == 'ncl_small':
cmaps = ncl_small
elif cname.lower() == 'ncl_meteo_swiss':
cmaps = ncl_meteo_swiss
elif cname.lower() == 'mma' or cname.lower() == 'mathematica':
cmaps = mathematica
else:
cmaps = [cname]
cmaps = [capitalise(cc) for cc in cmaps]
for i in cmaps:
cpool = all_maps[i][:]
if i in all255_maps:
cpool = [rgb2rgb01(*j) for j in cpool]
if reverse:
cpool = cpool[::-1]
if grey or gray:
for j in range(len(cpool)):
isgray = 0.2125 * cpool[j][0] + 0.7154 * cpool[j][
1] + 0.072 * cpool[j][2]
cpool[j] = (isgray, isgray, isgray)
cmap = ListedColormap(cpool, i)
register_cmap(cmap=cmap)
def bezier(icolors,
ncol=255,
correctlightness=True,
reverse=False,
cmap=None,
lch=False):
"""
interpolates between a set of colors using a bezier spline
"""
# Bezier interpolation functions
int2 = lambda c0, c1, t: (1. - t) * c0 + t * c1
int3 = lambda c0, c1, c2, t: (1. - t) * (1. - t) * c0 + 2. * (
1. - t) * t * c1 + t * t * c2
int4 = lambda c0, c1, c2, c3, t: (1. - t) * (1. - t) * (
1. - t) * c0 + 3. * (1. - t) * (1. - t) * t * c1 + 3. * (
1. - t) * t * t * c2 + t * t * t * c3
# Check
assert ncol > 1, 'Number of interpolated colours must be > 1'
# Convert colours to L*a*b
if lch:
colors = [rgb2lch(*col2rgb(i)) for i in icolors] # in lab
else:
colors = [rgb2lab(*col2rgb(i)) for i in icolors] # in lab
# Check - 2
icol = len(colors)
if (icol > 5):
raise ValueError('number of input colors > 5 not supported.')
# Check sequential or diverging colours, i.e. check for increasing/decreasing lightness
if (icol > 1):
lights = np.array([i[0] for i in colors])
dlight = np.diff(lights)
if np.all(dlight < 0.) or np.all(dlight >= 0.):
idiverge = False
# if icol > 4:
# raise ValueError('only diverging colours supported in case of 5 input colours.')
else:
idiverge = True
if icol == 4:
print('ll', lights)
raise ValueError(
'colours must have increasing or decreasing lightness in case of even number of colors: '
+ ',' + ','.join([str(i) for i in lights]))
# Interpolate colours
if icol == 1:
lab = [colors[0] for i in range(ncol)]
elif icol == 2:
lab0 = colors[0]
lab1 = colors[1]
# linear interpolation
lab = list()
for it in range(ncol):
t = float(it) / float(ncol - 1)
if correctlightness:
t = correct_lightness(int2, lab0[0], lab1[0], t)
lab.append(tuple([int2(lab0[i], lab1[i], t) for i in range(3)]))
elif icol == 3:
if idiverge:
assert (
ncol % 2
) == 1, 'number of colors has to be odd for bezier interpolation with 3 diverging colors.'
ncol2 = ncol // 2 + 1
# two separate interpolations
col1 = bezier(icolors[:2], ncol2)
col2 = bezier(icolors[1:], ncol2)
col1.extend(col2[1:])
if lch:
lab = [rgb2lch(*rgb012rgb(*i)) for i in col1]
else:
lab = [rgb2lab(*rgb012rgb(*i)) for i in col1]
else:
lab0 = colors[0]
lab1 = colors[1]
lab2 = colors[2]
# quadratic bezier interpolation
lab = list()
for it in range(ncol):
t = float(it) / float(ncol - 1)
if correctlightness:
t = correct_lightness(int3, lab0[0], lab1[0], lab2[0], t)
lab.append(
tuple([
int3(lab0[i], lab1[i], lab2[i], t) for i in range(3)
]))
elif icol == 4:
lab0 = colors[0]
lab1 = colors[1]
lab2 = colors[2]
lab3 = colors[3]
# cubic bezier interpolation
lab = list()
for it in range(ncol):
t = float(it) / float(ncol - 1)
if correctlightness:
t = correct_lightness(int4, lab0[0], lab1[0], lab2[0], lab3[0],
t)
lab.append(
tuple([
int4(lab0[i], lab1[i], lab2[i], lab3[i], t)
for i in range(3)
]))
elif icol == 5:
assert (
ncol % 2
) == 1, 'number of colors has to be odd for bezier interpolation with 5 colors.'
ncol2 = ncol // 2 + 1
col1 = bezier(icolors[:3], ncol2)
col2 = bezier(icolors[2:], ncol2)
col1.extend(col2[1:])
if lch:
lab = [rgb2lch(*rgb012rgb(*i)) for i in col1]
else:
lab = [rgb2lab(*rgb012rgb(*i)) for i in col1]
else:
raise ValueError('number of input colors > 5 not supported.')
# Reverse colours
if reverse:
lab = lab[::-1]
# rgb [0-1]
if lch:
cout = [rgb2rgb01(*lch2rgb(*i)) for i in lab]
else:
cout = [rgb2rgb01(*lab2rgb(*i)) for i in lab]
# Register colour map with matplotlib
if cmap is not None:
from matplotlib.colors import ListedColormap
from matplotlib.cm import register_cmap
iscmap = ListedColormap(cout, name=cmap, N=ncol)
register_cmap(name=cmap, cmap=iscmap)
return cout
def get_brewer(cname=None,
names=False,
rgb=False,
rgb256=False,
reverse=False,
grey=False,
gray=False):
"""
Get colour map either as registered handle or as RGB values (0-255 or 0-1).
Examples
--------
>>> import numpy as np
>>> from jams.autostring import astr
>>> cc = get_brewer('blues4',rgb=True)
>>> print(astr(np.array(cc[0]), 4))
['0.9373' '0.9529' '1.0000']
>>> cc = get_brewer('Blues4',rgb256=True)
>>> print(cc[0])
(239, 243, 255)
>>> cc = get_brewer('bLuEs4',rgb256=True,reverse=True)
>>> print(cc[-1])
(239, 243, 255)
>>> print(cc[0])
(33, 113, 181)
>>> cc = get_brewer('blues4',rgb256=True,grey=True)
>>> print(astr(np.array(cc[0]), 4))
['242.9897' '242.9897' '242.9897']
"""
from jams.color import rgb2rgb01, rgb012rgb
if names:
if names.lower() == 'sequential':
return list(brewer_sequential.keys())
elif names.lower() == 'diverging':
return list(brewer_diverging.keys())
elif names.lower() == 'qualitative':
return list(brewer_qualitative.keys())
elif names.lower() == 'osu':
return list(oregon.keys())
elif names.lower() == 'ncl_large':
return list(ncl_large.keys())
elif names.lower() == 'ncl_small':
return list(ncl_small.keys())
elif names.lower() == 'ncl_meteo_swiss':
return list(ncl_meteo_swiss.keys())
elif names.lower() == 'mma' or names.lower() == 'mathematica':
return list(mathematica.keys())
else:
cmaps = list(all_maps.keys())
return cmaps
else:
cname = capitalise(cname)
cpool = all_maps[cname][:]
if (not rgb) and (not rgb256):
# register colour map with matplotlib
from matplotlib.cm import get_cmap
register_brewer(cname, reverse=reverse, grey=grey, gray=gray)
return get_cmap(cname)
elif rgb:
# tuple 0-1
if cname in all255_maps:
cpool = [rgb2rgb01(*i) for i in cpool]
elif rgb256:
# tuple 0-255
if cname not in all255_maps:
cpool = [rgb012rgb(*i) for i in cpool]
if reverse:
cpool = cpool[::-1]
if grey or gray:
for j in range(len(cpool)):
isgray = 0.2125 * cpool[j][0] + 0.7154 * cpool[j][
1] + 0.072 * cpool[j][2]
cpool[j] = (isgray, isgray, isgray)
return cpool