Colors

This module defines a Color object and helper functions (see, e.g., hue(), rainbow()), as well as a set of colors and colormaps to use with Graphics objects in Sage.

For a list of pre-defined colors in Sage, evaluate:

Sage

sage: sorted(colors)
['aliceblue', 'antiquewhite', 'aqua', 'aquamarine', 'automatic', ...]

Python

>>> from sage.all import *
>>> sorted(colors)
['aliceblue', 'antiquewhite', 'aqua', 'aquamarine', 'automatic', ...]

Sage Live

sorted(colors)

Apart from ‘automatic’ which just an alias for ‘lightblue’, this list comprises the “official” W3C CSS3 / SVG colors.

For a list of color maps in Sage, evaluate:

Sage

sage: sorted(colormaps)
['Accent', ...]

Python

>>> from sage.all import *
>>> sorted(colormaps)
['Accent', ...]

Sage Live

sorted(colormaps)

These are imported from matplotlib’s colormaps collection.

class sage.plot.colors.Color(r='#0000ff', g=None, b=None, space='rgb')

Bases: object

A Red-Green-Blue (RGB) color model color object. For most consumer-grade devices (e.g., CRTs, LCDs, and printers), as well as internet applications, this is a point in the sRGB absolute color space. The Hue-Saturation-Lightness (HSL), Hue-Lightness-Saturation (HLS), and Hue-Saturation-Value (HSV) spaces are useful alternate representations, or coordinate transformations, of this space. Coordinates in all of these spaces are floating point values in the interval [0.0, 1.0].

Note

All instantiations of Color are converted to an internal RGB floating point 3-tuple. This is likely to degrade precision.

INPUT:

• r, g, b – either a triple of floats between 0 and 1, OR r - a color name string or HTML color hex string

• space – string (default: 'rgb'); the coordinate system (other choices are 'hsl', 'hls', and 'hsv') in which to interpret a triple of floats

EXAMPLES:

Sage

sage: Color('purple')
RGB color (0.5019607843137255, 0.0, 0.5019607843137255)
sage: Color('#8000ff')
RGB color (0.5019607843137255, 0.0, 1.0)
sage: Color(0.5,0,1)
RGB color (0.5, 0.0, 1.0)
sage: Color(0.5, 1.0, 1, space='hsv')
RGB color (0.0, 1.0, 1.0)
sage: Color(0.25, 0.5, 0.5, space='hls')
RGB color (0.5000000000000001, 0.75, 0.25)
sage: Color(1, 0, 1/3, space='hsl')
RGB color (0.3333333333333333, 0.3333333333333333, 0.3333333333333333)
sage: from sage.plot.colors import chocolate
sage: Color(chocolate)
RGB color (0.8235294117647058, 0.4117647058823529, 0.11764705882352941)

Python

>>> from sage.all import *
>>> Color('purple')
RGB color (0.5019607843137255, 0.0, 0.5019607843137255)
>>> Color('#8000ff')
RGB color (0.5019607843137255, 0.0, 1.0)
>>> Color(RealNumber('0.5'),Integer(0),Integer(1))
RGB color (0.5, 0.0, 1.0)
>>> Color(RealNumber('0.5'), RealNumber('1.0'), Integer(1), space='hsv')
RGB color (0.0, 1.0, 1.0)
>>> Color(RealNumber('0.25'), RealNumber('0.5'), RealNumber('0.5'), space='hls')
RGB color (0.5000000000000001, 0.75, 0.25)
>>> Color(Integer(1), Integer(0), Integer(1)/Integer(3), space='hsl')
RGB color (0.3333333333333333, 0.3333333333333333, 0.3333333333333333)
>>> from sage.plot.colors import chocolate
>>> Color(chocolate)
RGB color (0.8235294117647058, 0.4117647058823529, 0.11764705882352941)

Sage Live

Color('purple')
Color('#8000ff')
Color(0.5,0,1)
Color(0.5, 1.0, 1, space='hsv')
Color(0.25, 0.5, 0.5, space='hls')
Color(1, 0, 1/3, space='hsl')
from sage.plot.colors import chocolate
Color(chocolate)

blend(color, fraction=0.5)

Return a color blended with the given color by a given fraction. The algorithm interpolates linearly between the colors’ corresponding R, G, and B coordinates.

INPUT:

• color – a Color instance or float-convertible 3-tuple/list; the color with which to blend this color

• fraction – a float-convertible number; the fraction of color to blend with this color

OUTPUT: a new Color instance

EXAMPLES:

Sage

sage: from sage.plot.colors import red, blue, lime
sage: red.blend(blue)
RGB color (0.5, 0.0, 0.5)
sage: red.blend(blue, fraction=0.0)
RGB color (1.0, 0.0, 0.0)
sage: red.blend(blue, fraction=1.0)
RGB color (0.0, 0.0, 1.0)
sage: lime.blend((0.3, 0.5, 0.7))
RGB color (0.15, 0.75, 0.35)
sage: blue.blend(blue)
RGB color (0.0, 0.0, 1.0)
sage: red.blend(lime, fraction=0.3)
RGB color (0.7, 0.3, 0.0)
sage: blue.blend((0.0, 0.9, 0.2), fraction=0.2)
RGB color (0.0, 0.18000000000000002, 0.8400000000000001)
sage: red.blend(0.2)
Traceback (most recent call last):
...
TypeError: 0.200000000000000 must be a Color or float-convertible 3-tuple/list

Python

>>> from sage.all import *
>>> from sage.plot.colors import red, blue, lime
>>> red.blend(blue)
RGB color (0.5, 0.0, 0.5)
>>> red.blend(blue, fraction=RealNumber('0.0'))
RGB color (1.0, 0.0, 0.0)
>>> red.blend(blue, fraction=RealNumber('1.0'))
RGB color (0.0, 0.0, 1.0)
>>> lime.blend((RealNumber('0.3'), RealNumber('0.5'), RealNumber('0.7')))
RGB color (0.15, 0.75, 0.35)
>>> blue.blend(blue)
RGB color (0.0, 0.0, 1.0)
>>> red.blend(lime, fraction=RealNumber('0.3'))
RGB color (0.7, 0.3, 0.0)
>>> blue.blend((RealNumber('0.0'), RealNumber('0.9'), RealNumber('0.2')), fraction=RealNumber('0.2'))
RGB color (0.0, 0.18000000000000002, 0.8400000000000001)
>>> red.blend(RealNumber('0.2'))
Traceback (most recent call last):
...
TypeError: 0.200000000000000 must be a Color or float-convertible 3-tuple/list

Sage Live

from sage.plot.colors import red, blue, lime
red.blend(blue)
red.blend(blue, fraction=0.0)
red.blend(blue, fraction=1.0)
lime.blend((0.3, 0.5, 0.7))
blue.blend(blue)
red.blend(lime, fraction=0.3)
blue.blend((0.0, 0.9, 0.2), fraction=0.2)
red.blend(0.2)

darker(fraction=0.3333333333333333)

Return a darker “shade” of this RGB color by blend()-ing it with black. This is not an inverse of lighter().

INPUT:

• fraction – a float (default: 1/3); blending fraction to apply

OUTPUT: a new instance of Color

EXAMPLES:

Sage

sage: from sage.plot.colors import black
sage: vector(black.darker().rgb()) == vector(black.rgb())
True
sage: Color(0.4, 0.6, 0.8).darker(0.1)
RGB color (0.36000000000000004, 0.54, 0.7200000000000001)
sage: Color(.1,.2,.3,space='hsl').darker()
RGB color (0.24000000000000002, 0.20800000000000002, 0.16)

Python

>>> from sage.all import *
>>> from sage.plot.colors import black
>>> vector(black.darker().rgb()) == vector(black.rgb())
True
>>> Color(RealNumber('0.4'), RealNumber('0.6'), RealNumber('0.8')).darker(RealNumber('0.1'))
RGB color (0.36000000000000004, 0.54, 0.7200000000000001)
>>> Color(RealNumber('.1'),RealNumber('.2'),RealNumber('.3'),space='hsl').darker()
RGB color (0.24000000000000002, 0.20800000000000002, 0.16)

Sage Live

from sage.plot.colors import black
vector(black.darker().rgb()) == vector(black.rgb())
Color(0.4, 0.6, 0.8).darker(0.1)
Color(.1,.2,.3,space='hsl').darker()

hls()

Return the Hue-Lightness-Saturation (HLS) coordinates of this color.

OUTPUT: a 3-tuple of floats

EXAMPLES:

Sage

sage: Color(0.3, 0.5, 0.7, space='hls').hls()
(0.30000000000000004, 0.5, 0.7)
sage: Color(0.3, 0.5, 0.7, space='hsl').hls() # abs tol 1e-15
(0.30000000000000004, 0.7, 0.5000000000000001)
sage: Color('#aabbcc').hls() # abs tol 1e-15
(0.5833333333333334, 0.7333333333333334, 0.25000000000000017)
sage: from sage.plot.colors import orchid
sage: orchid.hls() # abs tol 1e-15
(0.8396226415094339, 0.6470588235294117, 0.5888888888888889)

Python

>>> from sage.all import *
>>> Color(RealNumber('0.3'), RealNumber('0.5'), RealNumber('0.7'), space='hls').hls()
(0.30000000000000004, 0.5, 0.7)
>>> Color(RealNumber('0.3'), RealNumber('0.5'), RealNumber('0.7'), space='hsl').hls() # abs tol 1e-15
(0.30000000000000004, 0.7, 0.5000000000000001)
>>> Color('#aabbcc').hls() # abs tol 1e-15
(0.5833333333333334, 0.7333333333333334, 0.25000000000000017)
>>> from sage.plot.colors import orchid
>>> orchid.hls() # abs tol 1e-15
(0.8396226415094339, 0.6470588235294117, 0.5888888888888889)

Sage Live

Color(0.3, 0.5, 0.7, space='hls').hls()
Color(0.3, 0.5, 0.7, space='hsl').hls() # abs tol 1e-15
Color('#aabbcc').hls() # abs tol 1e-15
from sage.plot.colors import orchid
orchid.hls() # abs tol 1e-15

hsl()

Return the Hue-Saturation-Lightness (HSL) coordinates of this color.

OUTPUT: a 3-tuple of floats

EXAMPLES:

Sage

sage: Color(1,0,0).hsl()
(0.0, 1.0, 0.5)
sage: from sage.plot.colors import orchid
sage: orchid.hsl() # abs tol 1e-15
(0.8396226415094339, 0.5888888888888889, 0.6470588235294117)
sage: Color('#aabbcc').hsl() # abs tol 1e-15
(0.5833333333333334, 0.25000000000000017, 0.7333333333333334)

Python

>>> from sage.all import *
>>> Color(Integer(1),Integer(0),Integer(0)).hsl()
(0.0, 1.0, 0.5)
>>> from sage.plot.colors import orchid
>>> orchid.hsl() # abs tol 1e-15
(0.8396226415094339, 0.5888888888888889, 0.6470588235294117)
>>> Color('#aabbcc').hsl() # abs tol 1e-15
(0.5833333333333334, 0.25000000000000017, 0.7333333333333334)

Sage Live

Color(1,0,0).hsl()
from sage.plot.colors import orchid
orchid.hsl() # abs tol 1e-15
Color('#aabbcc').hsl() # abs tol 1e-15

hsv()

Return the Hue-Saturation-Value (HSV) coordinates of this color.

OUTPUT: a 3-tuple of floats

EXAMPLES:

Sage

sage: from sage.plot.colors import red
sage: red.hsv()
(0.0, 1.0, 1.0)
sage: Color(1,1,1).hsv()
(0.0, 0.0, 1.0)
sage: Color('gray').hsv()
(0.0, 0.0, 0.5019607843137255)

Python

>>> from sage.all import *
>>> from sage.plot.colors import red
>>> red.hsv()
(0.0, 1.0, 1.0)
>>> Color(Integer(1),Integer(1),Integer(1)).hsv()
(0.0, 0.0, 1.0)
>>> Color('gray').hsv()
(0.0, 0.0, 0.5019607843137255)

Sage Live

from sage.plot.colors import red
red.hsv()
Color(1,1,1).hsv()
Color('gray').hsv()

html_color()

Return a HTML hex representation for this color.

OUTPUT: string of length 7

EXAMPLES:

Sage

sage: Color('yellow').html_color()
'#ffff00'
sage: Color('#fedcba').html_color()
'#fedcba'
sage: Color(0.0, 1.0, 0.0).html_color()
'#00ff00'
sage: from sage.plot.colors import honeydew
sage: honeydew.html_color()
'#f0fff0'

Python

>>> from sage.all import *
>>> Color('yellow').html_color()
'#ffff00'
>>> Color('#fedcba').html_color()
'#fedcba'
>>> Color(RealNumber('0.0'), RealNumber('1.0'), RealNumber('0.0')).html_color()
'#00ff00'
>>> from sage.plot.colors import honeydew
>>> honeydew.html_color()
'#f0fff0'

Sage Live

Color('yellow').html_color()
Color('#fedcba').html_color()
Color(0.0, 1.0, 0.0).html_color()
from sage.plot.colors import honeydew
honeydew.html_color()

lighter(fraction=0.3333333333333333)

Return a lighter “shade” of this RGB color by blend()-ing it with white. This is not an inverse of darker().

INPUT:

• fraction – a float (default: 1/3); blending fraction to apply

OUTPUT: a new instance of Color

EXAMPLES:

Sage

sage: from sage.plot.colors import khaki
sage: khaki.lighter()
RGB color (0.9607843137254903, 0.934640522875817, 0.6993464052287582)
sage: Color('white').lighter().darker()
RGB color (0.6666666666666667, 0.6666666666666667, 0.6666666666666667)
sage: Color('#abcdef').lighter(1/4)
RGB color (0.7529411764705882, 0.8529411764705883, 0.9529411764705882)
sage: Color(1, 0, 8/9, space='hsv').lighter()
RGB color (0.925925925925926, 0.925925925925926, 0.925925925925926)

Python

>>> from sage.all import *
>>> from sage.plot.colors import khaki
>>> khaki.lighter()
RGB color (0.9607843137254903, 0.934640522875817, 0.6993464052287582)
>>> Color('white').lighter().darker()
RGB color (0.6666666666666667, 0.6666666666666667, 0.6666666666666667)
>>> Color('#abcdef').lighter(Integer(1)/Integer(4))
RGB color (0.7529411764705882, 0.8529411764705883, 0.9529411764705882)
>>> Color(Integer(1), Integer(0), Integer(8)/Integer(9), space='hsv').lighter()
RGB color (0.925925925925926, 0.925925925925926, 0.925925925925926)

Sage Live

from sage.plot.colors import khaki
khaki.lighter()
Color('white').lighter().darker()
Color('#abcdef').lighter(1/4)
Color(1, 0, 8/9, space='hsv').lighter()

rgb()

Return the underlying Red-Green-Blue (RGB) coordinates of this color.

OUTPUT: a 3-tuple of floats

EXAMPLES:

Sage

sage: Color(0.3, 0.5, 0.7).rgb()
(0.3, 0.5, 0.7)
sage: Color('#8000ff').rgb()
(0.5019607843137255, 0.0, 1.0)
sage: from sage.plot.colors import orange
sage: orange.rgb()
(1.0, 0.6470588235294118, 0.0)
sage: Color('magenta').rgb()
(1.0, 0.0, 1.0)
sage: Color(1, 0.7, 0.9, space='hsv').rgb()
(0.9, 0.2700000000000001, 0.2700000000000001)

Python

>>> from sage.all import *
>>> Color(RealNumber('0.3'), RealNumber('0.5'), RealNumber('0.7')).rgb()
(0.3, 0.5, 0.7)
>>> Color('#8000ff').rgb()
(0.5019607843137255, 0.0, 1.0)
>>> from sage.plot.colors import orange
>>> orange.rgb()
(1.0, 0.6470588235294118, 0.0)
>>> Color('magenta').rgb()
(1.0, 0.0, 1.0)
>>> Color(Integer(1), RealNumber('0.7'), RealNumber('0.9'), space='hsv').rgb()
(0.9, 0.2700000000000001, 0.2700000000000001)

Sage Live

Color(0.3, 0.5, 0.7).rgb()
Color('#8000ff').rgb()
from sage.plot.colors import orange
orange.rgb()
Color('magenta').rgb()
Color(1, 0.7, 0.9, space='hsv').rgb()

class sage.plot.colors.Colormaps

Bases: MutableMapping

A dict-like collection of lazily-loaded matplotlib color maps. For a list of map names, evaluate:

Sage

sage: sorted(colormaps)
['Accent', ...]

Python

>>> from sage.all import *
>>> sorted(colormaps)
['Accent', ...]

Sage Live

sorted(colormaps)

load_maps()

If it’s necessary, loads matplotlib’s color maps and adds them to the collection.

EXAMPLES:

Sage

sage: from sage.plot.colors import Colormaps
sage: maps = Colormaps()
sage: len(maps.maps)
0
sage: maps.load_maps()
sage: len(maps.maps)>60
True
sage: 'viridis' in maps
True

Python

>>> from sage.all import *
>>> from sage.plot.colors import Colormaps
>>> maps = Colormaps()
>>> len(maps.maps)
0
>>> maps.load_maps()
>>> len(maps.maps)>Integer(60)
True
>>> 'viridis' in maps
True

Sage Live

from sage.plot.colors import Colormaps
maps = Colormaps()
len(maps.maps)
maps.load_maps()
len(maps.maps)>60
'viridis' in maps

class sage.plot.colors.ColorsDict

Bases: dict

A dict-like collection of colors, accessible via key or attribute. For a list of color names, evaluate:

Sage

sage: sorted(colors)
['aliceblue', 'antiquewhite', 'aqua', 'aquamarine', ...]

Python

>>> from sage.all import *
>>> sorted(colors)
['aliceblue', 'antiquewhite', 'aqua', 'aquamarine', ...]

Sage Live

sorted(colors)

sage.plot.colors.check_color_data(cfcm)

Make sure that the arguments are in order (coloring function, colormap).

This will allow users to use both possible orders.

EXAMPLES:

Sage

sage: from sage.plot.colors import check_color_data
sage: cf = lambda x,y : (x+y) % 1
sage: cm = colormaps.autumn
sage: check_color_data((cf, cm)) == (cf, cm)
True
sage: check_color_data((cm, cf)) == (cf, cm)
True

Python

>>> from sage.all import *
>>> from sage.plot.colors import check_color_data
>>> cf = lambda x,y : (x+y) % Integer(1)
>>> cm = colormaps.autumn
>>> check_color_data((cf, cm)) == (cf, cm)
True
>>> check_color_data((cm, cf)) == (cf, cm)
True

Sage Live

from sage.plot.colors import check_color_data
cf = lambda x,y : (x+y) % 1
cm = colormaps.autumn
check_color_data((cf, cm)) == (cf, cm)
check_color_data((cm, cf)) == (cf, cm)

sage.plot.colors.float_to_html(r, g, b)

Convert a Red-Green-Blue (RGB) color tuple to a HTML hex color.

Each input value should be in the interval [0.0, 1.0]; otherwise, the values are first reduced modulo one (see mod_one()).

INPUT:

• r – a real number; the RGB color’s “red” intensity

• g – a real number; the RGB color’s “green” intensity

• b – a real number; the RGB color’s “blue” intensity

OUTPUT: string of length 7, starting with '#'

EXAMPLES:

Sage

sage: from sage.plot.colors import float_to_html
sage: float_to_html(1.,1.,0.)
'#ffff00'
sage: float_to_html(.03,.06,.02)
'#070f05'
sage: float_to_html(*Color('brown').rgb())
'#a52a2a'

Python

>>> from sage.all import *
>>> from sage.plot.colors import float_to_html
>>> float_to_html(RealNumber('1.'),RealNumber('1.'),RealNumber('0.'))
'#ffff00'
>>> float_to_html(RealNumber('.03'),RealNumber('.06'),RealNumber('.02'))
'#070f05'
>>> float_to_html(*Color('brown').rgb())
'#a52a2a'

Sage Live

from sage.plot.colors import float_to_html
float_to_html(1.,1.,0.)
float_to_html(.03,.06,.02)
float_to_html(*Color('brown').rgb())

sage.plot.colors.float_to_integer(r, g, b)

Convert a Red-Green-Blue (RGB) color tuple to an integer.

Each input value should be in the interval [0.0, 1.0]; otherwise, the values are first reduced modulo one (see mod_one()).

INPUT:

• r – a real number; the RGB color’s “red” intensity

• g – a real number; the RGB color’s “green” intensity

• b – a real number; the RGB color’s “blue” intensity

OUTPUT:

The integer 256^2 r_int + 256 g_int + b_int, where r_int, g_int, and b_int are obtained from r, g, and b by converting from the real interval [0.0, 1.0] to the integer range 0, 1, …, 255.

EXAMPLES:

Sage

sage: from sage.plot.colors import float_to_integer
sage: float_to_integer(1.,1.,0.)
16776960
sage: float_to_integer(.03,.06,.02)
462597
sage: float_to_integer(*Color('brown').rgb())
10824234

Python

>>> from sage.all import *
>>> from sage.plot.colors import float_to_integer
>>> float_to_integer(RealNumber('1.'),RealNumber('1.'),RealNumber('0.'))
16776960
>>> float_to_integer(RealNumber('.03'),RealNumber('.06'),RealNumber('.02'))
462597
>>> float_to_integer(*Color('brown').rgb())
10824234

Sage Live

from sage.plot.colors import float_to_integer
float_to_integer(1.,1.,0.)
float_to_integer(.03,.06,.02)
float_to_integer(*Color('brown').rgb())

sage.plot.colors.get_cmap(cmap)

Return a color map (actually, a matplotlib Colormap object), given its name or a [mixed] list/tuple of RGB list/tuples and color names. For a list of map names, evaluate:

Sage

sage: sorted(colormaps)
['Accent', ...]

Python

>>> from sage.all import *
>>> sorted(colormaps)
['Accent', ...]

Sage Live

sorted(colormaps)

See rgbcolor() for valid list/tuple element formats.

INPUT:

• cmap – string, list, tuple, or matplotlib.colors.Colormap; a string must be a valid color map name

OUTPUT: a matplotlib.colors.Colormap instance

EXAMPLES:

Sage

sage: from sage.plot.colors import get_cmap
sage: get_cmap('jet')
<matplotlib.colors.LinearSegmentedColormap object at 0x...>
sage: get_cmap([(0,0,0), (0.5,0.5,0.5), (1,1,1)])
<matplotlib.colors.ListedColormap object at 0x...>
sage: get_cmap(['green', 'lightblue', 'blue'])
<matplotlib.colors.ListedColormap object at 0x...>
sage: get_cmap(((0.5, 0.3, 0.2), [1.0, 0.0, 0.5], 'purple', Color(0.5,0.5,1, space='hsv')))
<matplotlib.colors.ListedColormap object at 0x...>
sage: get_cmap('jolies')
Traceback (most recent call last):
...
RuntimeError: Color map jolies not known (type "import matplotlib; list(matplotlib.colormaps.keys())" for valid names)
sage: get_cmap('mpl')
Traceback (most recent call last):
...
RuntimeError: Color map mpl not known (type "import matplotlib; list(matplotlib.colormaps.keys())" for valid names)

Python

>>> from sage.all import *
>>> from sage.plot.colors import get_cmap
>>> get_cmap('jet')
<matplotlib.colors.LinearSegmentedColormap object at 0x...>
>>> get_cmap([(Integer(0),Integer(0),Integer(0)), (RealNumber('0.5'),RealNumber('0.5'),RealNumber('0.5')), (Integer(1),Integer(1),Integer(1))])
<matplotlib.colors.ListedColormap object at 0x...>
>>> get_cmap(['green', 'lightblue', 'blue'])
<matplotlib.colors.ListedColormap object at 0x...>
>>> get_cmap(((RealNumber('0.5'), RealNumber('0.3'), RealNumber('0.2')), [RealNumber('1.0'), RealNumber('0.0'), RealNumber('0.5')], 'purple', Color(RealNumber('0.5'),RealNumber('0.5'),Integer(1), space='hsv')))
<matplotlib.colors.ListedColormap object at 0x...>
>>> get_cmap('jolies')
Traceback (most recent call last):
...
RuntimeError: Color map jolies not known (type "import matplotlib; list(matplotlib.colormaps.keys())" for valid names)
>>> get_cmap('mpl')
Traceback (most recent call last):
...
RuntimeError: Color map mpl not known (type "import matplotlib; list(matplotlib.colormaps.keys())" for valid names)

Sage Live

from sage.plot.colors import get_cmap
get_cmap('jet')
get_cmap([(0,0,0), (0.5,0.5,0.5), (1,1,1)])
get_cmap(['green', 'lightblue', 'blue'])
get_cmap(((0.5, 0.3, 0.2), [1.0, 0.0, 0.5], 'purple', Color(0.5,0.5,1, space='hsv')))
get_cmap('jolies')
get_cmap('mpl')

sage.plot.colors.html_to_float(c)

Convert a HTML hex color to a Red-Green-Blue (RGB) tuple.

INPUT:

• c – string; a valid HTML hex color

OUTPUT: a RGB 3-tuple of floats in the interval [0.0, 1.0]

EXAMPLES:

Sage

sage: from sage.plot.colors import html_to_float
sage: html_to_float('#fff')
(1.0, 1.0, 1.0)
sage: html_to_float('#abcdef')
(0.6705882352941176, 0.803921568627451, 0.9372549019607843)
sage: html_to_float('#123xyz')
Traceback (most recent call last):
...
ValueError: invalid literal for int() with base 16: '3x'

Python

>>> from sage.all import *
>>> from sage.plot.colors import html_to_float
>>> html_to_float('#fff')
(1.0, 1.0, 1.0)
>>> html_to_float('#abcdef')
(0.6705882352941176, 0.803921568627451, 0.9372549019607843)
>>> html_to_float('#123xyz')
Traceback (most recent call last):
...
ValueError: invalid literal for int() with base 16: '3x'

Sage Live

from sage.plot.colors import html_to_float
html_to_float('#fff')
html_to_float('#abcdef')
html_to_float('#123xyz')

sage.plot.colors.hue(h, s=1, v=1)

Convert a Hue-Saturation-Value (HSV) color tuple to a valid Red-Green-Blue (RGB) tuple. All three inputs should lie in the interval [0.0, 1.0]; otherwise, they are reduced modulo 1 (see mod_one()). In particular h=0 and h=1 yield red, with the intermediate hues orange, yellow, green, cyan, blue, and violet as h increases.

This function makes it easy to sample a broad range of colors for graphics:

Sage

sage: # needs sage.symbolic
sage: p = Graphics()
sage: for phi in xsrange(0, 2 * pi, 1 / pi):
....:     p += plot(sin(x + phi), (x, -7, 7), rgbcolor=hue(phi))
sage: p
Graphics object consisting of 20 graphics primitives

Python

>>> from sage.all import *
>>> # needs sage.symbolic
>>> p = Graphics()
>>> for phi in xsrange(Integer(0), Integer(2) * pi, Integer(1) / pi):
...     p += plot(sin(x + phi), (x, -Integer(7), Integer(7)), rgbcolor=hue(phi))
>>> p
Graphics object consisting of 20 graphics primitives

Sage Live

# needs sage.symbolic
p = Graphics()
for phi in xsrange(0, 2 * pi, 1 / pi):
    p += plot(sin(x + phi), (x, -7, 7), rgbcolor=hue(phi))
p

INPUT:

• h – a number; the color’s hue

• s – a number (default: 1); the color’s saturation

• v – a number (default: 1); the color’s value

OUTPUT: a RGB 3-tuple of floats in the interval [0.0, 1.0]

EXAMPLES:

Sage

sage: hue(0.6)
(0.0, 0.40000000000000036, 1.0)
sage: from sage.plot.colors import royalblue
sage: royalblue
RGB color (0.2549019607843137, 0.4117647058823529, 0.8823529411764706)
sage: hue(*royalblue.hsv())
(0.2549019607843137, 0.4117647058823529, 0.8823529411764706)
sage: hue(.5, .5, .5)
(0.25, 0.5, 0.5)

Python

>>> from sage.all import *
>>> hue(RealNumber('0.6'))
(0.0, 0.40000000000000036, 1.0)
>>> from sage.plot.colors import royalblue
>>> royalblue
RGB color (0.2549019607843137, 0.4117647058823529, 0.8823529411764706)
>>> hue(*royalblue.hsv())
(0.2549019607843137, 0.4117647058823529, 0.8823529411764706)
>>> hue(RealNumber('.5'), RealNumber('.5'), RealNumber('.5'))
(0.25, 0.5, 0.5)

Sage Live

hue(0.6)
from sage.plot.colors import royalblue
royalblue
hue(*royalblue.hsv())
hue(.5, .5, .5)

Note

The HSV to RGB coordinate transformation itself is given in the source code for the Python library’s colorsys module:

Sage

sage: from colorsys import hsv_to_rgb    # not tested
sage: hsv_to_rgb??                       # not tested

Python

>>> from sage.all import *
>>> from colorsys import hsv_to_rgb    # not tested
>>> hsv_to_rgb??                       # not tested

Sage Live

from colorsys import hsv_to_rgb    # not tested
hsv_to_rgb??                       # not tested

sage.plot.colors.mod_one(x)

Reduce a number modulo 1.

INPUT:

• x – an instance of Integer, int, RealNumber, etc.; the number to reduce

OUTPUT: float

EXAMPLES:

Sage

sage: from sage.plot.colors import mod_one
sage: mod_one(1)
1.0
sage: mod_one(7.0)
0.0
sage: mod_one(-11/7)
0.4285714285714286
sage: mod_one(pi) + mod_one(-pi)                                                # needs sage.symbolic
1.0

Python

>>> from sage.all import *
>>> from sage.plot.colors import mod_one
>>> mod_one(Integer(1))
1.0
>>> mod_one(RealNumber('7.0'))
0.0
>>> mod_one(-Integer(11)/Integer(7))
0.4285714285714286
>>> mod_one(pi) + mod_one(-pi)                                                # needs sage.symbolic
1.0

Sage Live

from sage.plot.colors import mod_one
mod_one(1)
mod_one(7.0)
mod_one(-11/7)
mod_one(pi) + mod_one(-pi)                                                # needs sage.symbolic

sage.plot.colors.rainbow(n, format='hex')

Return a list of colors sampled at equal intervals over the spectrum, from Hue-Saturation-Value (HSV) coordinates (0, 1, 1) to (1, 1, 1). This range is red at the extremes, but it covers orange, yellow, green, cyan, blue, violet, and many other hues in between. This function is particularly useful for representing vertex partitions on graphs.

INPUT:

• n – a number; the length of the list

• format – string (default: 'hex'); the output format for each color in the list. The other choice is 'rgbtuple'.

OUTPUT: a list of strings or RGB 3-tuples of floats in the interval [0.0, 1.0]

EXAMPLES:

Sage

sage: from sage.plot.colors import rainbow
sage: rainbow(7)
['#ff0000', '#ffda00', '#48ff00', '#00ff91', '#0091ff', '#4800ff', '#ff00da']
sage: rainbow(int(7))
['#ff0000', '#ffda00', '#48ff00', '#00ff91', '#0091ff', '#4800ff', '#ff00da']
sage: rainbow(7, 'rgbtuple')
[(1.0, 0.0, 0.0), (1.0, 0.8571428571428571, 0.0), (0.2857142857142858, 1.0, 0.0), (0.0, 1.0, 0.5714285714285712), (0.0, 0.5714285714285716, 1.0), (0.2857142857142856, 0.0, 1.0), (1.0, 0.0, 0.8571428571428577)]

Python

>>> from sage.all import *
>>> from sage.plot.colors import rainbow
>>> rainbow(Integer(7))
['#ff0000', '#ffda00', '#48ff00', '#00ff91', '#0091ff', '#4800ff', '#ff00da']
>>> rainbow(int(Integer(7)))
['#ff0000', '#ffda00', '#48ff00', '#00ff91', '#0091ff', '#4800ff', '#ff00da']
>>> rainbow(Integer(7), 'rgbtuple')
[(1.0, 0.0, 0.0), (1.0, 0.8571428571428571, 0.0), (0.2857142857142858, 1.0, 0.0), (0.0, 1.0, 0.5714285714285712), (0.0, 0.5714285714285716, 1.0), (0.2857142857142856, 0.0, 1.0), (1.0, 0.0, 0.8571428571428577)]

Sage Live

from sage.plot.colors import rainbow
rainbow(7)
rainbow(int(7))
rainbow(7, 'rgbtuple')

AUTHORS:

• Robert L. Miller

• Karl-Dieter Crisman (directly use hsv_to_rgb() for hues)

sage.plot.colors.rgbcolor(c, space='rgb')

Convert a color (string, tuple, list, or Color) to a mod-one reduced (see mod_one()) valid Red-Green-Blue (RGB) tuple. The returned tuple is also a valid matplotlib RGB color.

INPUT:

• c – a Color instance, string (name or HTML hex), 3-tuple, or 3-list; the color to convert

• space – string (default: 'rgb'); the color space coordinate system (other choices are 'hsl', 'hls', and 'hsv') in which to interpret a 3-tuple or 3-list

OUTPUT: a RGB 3-tuple of floats in the interval [0.0, 1.0]

EXAMPLES:

Sage

sage: from sage.plot.colors import rgbcolor
sage: rgbcolor(Color(0.25, 0.4, 0.9))
(0.25, 0.4, 0.9)
sage: rgbcolor('purple')
(0.5019607843137255, 0.0, 0.5019607843137255)
sage: rgbcolor('#fa0')
(1.0, 0.6666666666666666, 0.0)
sage: rgbcolor('#ffffff')
(1.0, 1.0, 1.0)
sage: rgbcolor((1,1/2,1/3))
(1.0, 0.5, 0.3333333333333333)
sage: rgbcolor([1,1/2,1/3])
(1.0, 0.5, 0.3333333333333333)
sage: rgbcolor((1,1,1), space='hsv')
(1.0, 0.0, 0.0)
sage: rgbcolor((0.5,0.75,1), space='hls')
(0.5, 0.9999999999999999, 1.0)
sage: rgbcolor((0.5,1.0,0.75), space='hsl')
(0.5, 0.9999999999999999, 1.0)
sage: rgbcolor([1,2,255])   # WARNING -- numbers are reduced mod 1!!
(1.0, 0.0, 0.0)
sage: rgbcolor('#abcd')
Traceback (most recent call last):
...
ValueError: color hex string (= 'abcd') must have length 3 or 6
sage: rgbcolor('fff')
Traceback (most recent call last):
...
ValueError: unknown color 'fff'
sage: rgbcolor(1)
Traceback (most recent call last):
...
TypeError: '1' must be a Color, list, tuple, or string
sage: rgbcolor((0.2,0.8,1), space='grassmann')
Traceback (most recent call last):
...
ValueError: space must be one of 'rgb', 'hsv', 'hsl', 'hls'
sage: rgbcolor([0.4, 0.1])
Traceback (most recent call last):
...
ValueError: color list or tuple '[0.400000000000000, 0.100000000000000]' must have 3 entries, one for each RGB, HSV, HLS, or HSL channel

Python

>>> from sage.all import *
>>> from sage.plot.colors import rgbcolor
>>> rgbcolor(Color(RealNumber('0.25'), RealNumber('0.4'), RealNumber('0.9')))
(0.25, 0.4, 0.9)
>>> rgbcolor('purple')
(0.5019607843137255, 0.0, 0.5019607843137255)
>>> rgbcolor('#fa0')
(1.0, 0.6666666666666666, 0.0)
>>> rgbcolor('#ffffff')
(1.0, 1.0, 1.0)
>>> rgbcolor((Integer(1),Integer(1)/Integer(2),Integer(1)/Integer(3)))
(1.0, 0.5, 0.3333333333333333)
>>> rgbcolor([Integer(1),Integer(1)/Integer(2),Integer(1)/Integer(3)])
(1.0, 0.5, 0.3333333333333333)
>>> rgbcolor((Integer(1),Integer(1),Integer(1)), space='hsv')
(1.0, 0.0, 0.0)
>>> rgbcolor((RealNumber('0.5'),RealNumber('0.75'),Integer(1)), space='hls')
(0.5, 0.9999999999999999, 1.0)
>>> rgbcolor((RealNumber('0.5'),RealNumber('1.0'),RealNumber('0.75')), space='hsl')
(0.5, 0.9999999999999999, 1.0)
>>> rgbcolor([Integer(1),Integer(2),Integer(255)])   # WARNING -- numbers are reduced mod 1!!
(1.0, 0.0, 0.0)
>>> rgbcolor('#abcd')
Traceback (most recent call last):
...
ValueError: color hex string (= 'abcd') must have length 3 or 6
>>> rgbcolor('fff')
Traceback (most recent call last):
...
ValueError: unknown color 'fff'
>>> rgbcolor(Integer(1))
Traceback (most recent call last):
...
TypeError: '1' must be a Color, list, tuple, or string
>>> rgbcolor((RealNumber('0.2'),RealNumber('0.8'),Integer(1)), space='grassmann')
Traceback (most recent call last):
...
ValueError: space must be one of 'rgb', 'hsv', 'hsl', 'hls'
>>> rgbcolor([RealNumber('0.4'), RealNumber('0.1')])
Traceback (most recent call last):
...
ValueError: color list or tuple '[0.400000000000000, 0.100000000000000]' must have 3 entries, one for each RGB, HSV, HLS, or HSL channel

Sage Live

from sage.plot.colors import rgbcolor
rgbcolor(Color(0.25, 0.4, 0.9))
rgbcolor('purple')
rgbcolor('#fa0')
rgbcolor('#ffffff')
rgbcolor((1,1/2,1/3))
rgbcolor([1,1/2,1/3])
rgbcolor((1,1,1), space='hsv')
rgbcolor((0.5,0.75,1), space='hls')
rgbcolor((0.5,1.0,0.75), space='hsl')
rgbcolor([1,2,255])   # WARNING -- numbers are reduced mod 1!!
rgbcolor('#abcd')
rgbcolor('fff')
rgbcolor(1)
rgbcolor((0.2,0.8,1), space='grassmann')
rgbcolor([0.4, 0.1])

sage.plot.colors.to_mpl_color(c, space='rgb')

Convert a color (string, tuple, list, or Color) to a mod-one reduced (see mod_one()) valid Red-Green-Blue (RGB) tuple. The returned tuple is also a valid matplotlib RGB color.

INPUT:

• c – a Color instance, string (name or HTML hex), 3-tuple, or 3-list; the color to convert

• space – string (default: 'rgb'); the color space coordinate system (other choices are 'hsl', 'hls', and 'hsv') in which to interpret a 3-tuple or 3-list

OUTPUT: a RGB 3-tuple of floats in the interval [0.0, 1.0]

EXAMPLES:

Sage

sage: from sage.plot.colors import rgbcolor
sage: rgbcolor(Color(0.25, 0.4, 0.9))
(0.25, 0.4, 0.9)
sage: rgbcolor('purple')
(0.5019607843137255, 0.0, 0.5019607843137255)
sage: rgbcolor('#fa0')
(1.0, 0.6666666666666666, 0.0)
sage: rgbcolor('#ffffff')
(1.0, 1.0, 1.0)
sage: rgbcolor((1,1/2,1/3))
(1.0, 0.5, 0.3333333333333333)
sage: rgbcolor([1,1/2,1/3])
(1.0, 0.5, 0.3333333333333333)
sage: rgbcolor((1,1,1), space='hsv')
(1.0, 0.0, 0.0)
sage: rgbcolor((0.5,0.75,1), space='hls')
(0.5, 0.9999999999999999, 1.0)
sage: rgbcolor((0.5,1.0,0.75), space='hsl')
(0.5, 0.9999999999999999, 1.0)
sage: rgbcolor([1,2,255])   # WARNING -- numbers are reduced mod 1!!
(1.0, 0.0, 0.0)
sage: rgbcolor('#abcd')
Traceback (most recent call last):
...
ValueError: color hex string (= 'abcd') must have length 3 or 6
sage: rgbcolor('fff')
Traceback (most recent call last):
...
ValueError: unknown color 'fff'
sage: rgbcolor(1)
Traceback (most recent call last):
...
TypeError: '1' must be a Color, list, tuple, or string
sage: rgbcolor((0.2,0.8,1), space='grassmann')
Traceback (most recent call last):
...
ValueError: space must be one of 'rgb', 'hsv', 'hsl', 'hls'
sage: rgbcolor([0.4, 0.1])
Traceback (most recent call last):
...
ValueError: color list or tuple '[0.400000000000000, 0.100000000000000]' must have 3 entries, one for each RGB, HSV, HLS, or HSL channel

Python

>>> from sage.all import *
>>> from sage.plot.colors import rgbcolor
>>> rgbcolor(Color(RealNumber('0.25'), RealNumber('0.4'), RealNumber('0.9')))
(0.25, 0.4, 0.9)
>>> rgbcolor('purple')
(0.5019607843137255, 0.0, 0.5019607843137255)
>>> rgbcolor('#fa0')
(1.0, 0.6666666666666666, 0.0)
>>> rgbcolor('#ffffff')
(1.0, 1.0, 1.0)
>>> rgbcolor((Integer(1),Integer(1)/Integer(2),Integer(1)/Integer(3)))
(1.0, 0.5, 0.3333333333333333)
>>> rgbcolor([Integer(1),Integer(1)/Integer(2),Integer(1)/Integer(3)])
(1.0, 0.5, 0.3333333333333333)
>>> rgbcolor((Integer(1),Integer(1),Integer(1)), space='hsv')
(1.0, 0.0, 0.0)
>>> rgbcolor((RealNumber('0.5'),RealNumber('0.75'),Integer(1)), space='hls')
(0.5, 0.9999999999999999, 1.0)
>>> rgbcolor((RealNumber('0.5'),RealNumber('1.0'),RealNumber('0.75')), space='hsl')
(0.5, 0.9999999999999999, 1.0)
>>> rgbcolor([Integer(1),Integer(2),Integer(255)])   # WARNING -- numbers are reduced mod 1!!
(1.0, 0.0, 0.0)
>>> rgbcolor('#abcd')
Traceback (most recent call last):
...
ValueError: color hex string (= 'abcd') must have length 3 or 6
>>> rgbcolor('fff')
Traceback (most recent call last):
...
ValueError: unknown color 'fff'
>>> rgbcolor(Integer(1))
Traceback (most recent call last):
...
TypeError: '1' must be a Color, list, tuple, or string
>>> rgbcolor((RealNumber('0.2'),RealNumber('0.8'),Integer(1)), space='grassmann')
Traceback (most recent call last):
...
ValueError: space must be one of 'rgb', 'hsv', 'hsl', 'hls'
>>> rgbcolor([RealNumber('0.4'), RealNumber('0.1')])
Traceback (most recent call last):
...
ValueError: color list or tuple '[0.400000000000000, 0.100000000000000]' must have 3 entries, one for each RGB, HSV, HLS, or HSL channel

Sage Live

from sage.plot.colors import rgbcolor
rgbcolor(Color(0.25, 0.4, 0.9))
rgbcolor('purple')
rgbcolor('#fa0')
rgbcolor('#ffffff')
rgbcolor((1,1/2,1/3))
rgbcolor([1,1/2,1/3])
rgbcolor((1,1,1), space='hsv')
rgbcolor((0.5,0.75,1), space='hls')
rgbcolor((0.5,1.0,0.75), space='hsl')
rgbcolor([1,2,255])   # WARNING -- numbers are reduced mod 1!!
rgbcolor('#abcd')
rgbcolor('fff')
rgbcolor(1)
rgbcolor((0.2,0.8,1), space='grassmann')
rgbcolor([0.4, 0.1])

Make live