Implementation of the 'viridis' - the default -, 'magma', 'plasma',
'inferno', and 'cividis' color maps for 'R'. 'viridis', 'magma',
'plasma', and 'inferno' are ported from 'matplotlib'
<http://matplotlib.org/>, a popular plotting library for 'python'.
'cividis', was developed by Jamie R. Nuñez and Sean M. Colby. These
color maps are designed in such a way that they will analytically
be perfectly perceptually-uniform, both in regular form and also
when converted to black-and-white. They are also designed to be
perceived by readers with the most common form of color blindness
(all color maps in this package) and color vision deficiency
('cividis' only).