cmap
Scientific colormaps for python, with no dependencies beyond numpy.
With cmap
, you can use any of the colormaps from
matplotlib,
cmocean,
colorbrewer,
crameri,
seaborn, and a host
of other collections in your python code, without having to install matplotlib
or any other dependencies beyond numpy.
:book: See the complete
catalog
There are a number of python libraries that provide or require colormaps or
basic color support, but they all either depend on matplotlib, provide a
specialized set of colormaps intended to extend those provided by matplotlib, or
roll their own colormap solution that vendors/duplicates other libraries.
cmap
is a lightweight library that provides a large collection of colormaps
with no dependencies beyond numpy. It provides exports to a number of known
third-party colormap objects, allowing it to be used across a wide range of
python visualization libraries. The intention is to provide a library that can
be used by any python library that needs colormaps, without forcing the user to
install matplotlib (while still being compatible with matplotlib and other
libraries that use matplotlib colormaps).
cmap
is strictly typed and fully tested, with a focus on good developer
experience.
Install
pip install cmap
conda install -c conda-forge cmap
Usage
See Documentation for full details.
The cmap.Color
object is a simple wrapper around a tuple of RGBA scalars, with
a few convenience methods for converting to other color objects.
from cmap import Color
red = Color("red")
The cmap.Colormap
object is a callable that can map a scalar value (or numpy
array of values) to an RGBA color (or a numpy array of RGBA colors). API is
intended to mimic the behavior of a
matplotlib.colors.Colormap
object (without requiring matplotlib)
In [1]: import cmap
In [2]: cmap1 = cmap.Colormap(["red", "green", "blue"])
In [3]: cmap1(np.linspace(0,1,5))
Out[3]:
array([[1. , 0. , 0. , 1. ],
[0.50393701, 0.24900417, 0. , 1. ],
[0. , 0.50196078, 0. , 1. ],
[0. , 0.24900417, 0.50393701, 1. ],
[0. , 0. , 1. , 1. ]])
Note that the input array must be normalized from 0-1, so if you're applying a colormap
to an integer array (like an image) you must apply any contrast limits and rescale to
0-1 before passing it to a Colormap
.
Third Party Library Support
The cmap.Colormap
object has convenience methods that export it to a number of known
third-party colormap objects, including:
See documentation
for details.
If you would like to see support added for a particular library, please open an issue or PR.
Alternatives
Other libraries providing colormaps:
References and Further reading