brewer2mpl 1.3.2

Connect colorbrewer2.org color maps to Python and matplotlib

brewer2mpl is a pure Python package for accessing colorbrewer2.org color maps from Python. With brewer2mpl you can get the raw RGB colors of all 165 colorbrewer2.org color maps. The color map data ships with brewer2mpl so no internet connection is required.

For more information and to view some of the color maps see the wiki at https://github.com/jiffyclub/brewer2mpl/wiki.

Color Maps

colorbrewer2.org has 3 map types: sequential, diverging, and qualitative. Each color map has between 3 and 12 defined colors.

Examples

Listing Color Maps

List all of the available color maps:

brewer2mpl.print_maps()

List maps by type:

brewer2mpl.print_maps('sequential')

Filter by number of colors defined:

brewer2mpl.print_maps('qualitative', 6)

Get a Color Map

Color maps are accessed by name, type, and number:

bmap = brewer2mpl.get_map('Paired', 'Qualitative', 5)

If you want a color map reversed from how it is given by colorbrewer2.org set the reverse keyword to True:

bmap = brewer2mpl.get_map('Paired', 'Qualitative', 5, reverse=True)

BrewerMap Objects

Color maps are represented by BrewerMap objects. They have a few useful attributes:

# colorbrewer2.org url.
bmap.colorbrewer2_url

# colorbrewer2.org name
bmap.name

# number of defined colors
bmap.number

# colors as a list of RGB 0-255 triplets
bmap.colors

# colors as a list of hex strings
bmap.hex_colors

# colors as a list of RGB 0-1 triplets (as used by matplotlib)
bmap.mpl_colors

# matplotlib color map
bmap.mpl_colormap

To launch your browser and see a color map at colorbrewer2.org use the colorbrewer2 method:

bmap.colorbrewer2()

The matplotlib color maps are created using matplotlib.colors.LinearSegmentedColormap.from_list. If you want to pass options to that method use the BrewerMap.get_mpl_colormap method:

cmap = bmap.get_mpl_colormap(N=1000, gamma=2.0)

Direct Access

If you know the color map you want there is a shortcut for direct access. You can import the sequential, diverging, or qualitative modules from brewer2mpl. On the module namespace are dictionaries containing BrewerMap objects keyed by number of defined colors.

Say you want the Dark2 qualitative color map with 7 colors. To get it directly you can do:

from brewer2mpl import qualitative
bmap = qualitative.Dark2[7]

There is also a special key ‘max’ for each name that points to the color map with the most defined colors:

from brewer2mpl import sequential
bmap = sequential.YlGnBu['max']