lets_plot.scale_viridis

lets_plot.scale_viridis(aesthetic, *, alpha=None, begin=None, end=None, direction=None, option=None, name=None, breaks=None, labels=None, limits=None, na_value=None, guide=None, trans=None, format=None)

The viridis color maps are designed to be perceptually-uniform, both in regular form and also when converted to black-and-white.

The viridis color scales are suitable for viewers with common forms of colour blindness. See also https://bids.github.io/colormap/.

Parameters
aestheticstr or list

The name(s) of the aesthetic(s) that this scale works with.

alphafloat, default=1.0

Alpha transparency channel. (0 means transparent and 1 means opaque).

beginfloat, default=0.0

Correspond to a color hue to start at. Accept values between 0 and 1. Should be less than end.

endfloat, default=1.0

Correspond to a color hue to end with. Accept values between 0 and 1. Should be greater than begin.

direction{1, -1}, default=1

Set the order of colors in the scale. If -1, the order of colors is reversed.

optionstr, default=”D” (or “viridis”)
The colormap to use:

  • “magma” (or “A”),

  • “inferno” (or “B”)

  • “plasma” (or “C”)

  • “viridis” (or “D”)

  • “cividis” (or “E”)

  • “turbo”

  • “twilight”

namestr

The name of the scale - used as the axis label or the legend title. If None, the default, the name of the scale is taken from the first mapping used for that aesthetic.

breakslist

A vector specifying values to display as ticks on axis.

labelslist of str

A vector of labels (on ticks).

limitslist

Continuous scale: a numeric vector of length two providing limits of the scale. Discrete scale: a vector specifying the data range for the scale and the default order of their display in guides.

na_value

Missing values will be replaced with this value.

guide

Guide to use for this scale. It can either be a string (‘colorbar’, ‘legend’) or a call to a guide function (guide_colorbar(), guide_legend()) specifying additional arguments. ‘none’ will hide the guide.

trans{‘identity’, ‘log10’, ‘sqrt’, ‘reverse’}

Name of built-in transformation.

formatstr

Define the format for labels on the scale. The syntax resembles Python’s: ‘.2f’ -> ‘12.45’ ‘Num {}’ -> ‘Num 12.456789’ ‘TTL: {.2f}$’ -> ‘TTL: 12.45$’ For more info see https://lets-plot.org/pages/formats.html.

Returns
FeatureSpec or FeatureSpecArray

Scales specification.

Notes

Can be used for both, continuous and discrete data.

Examples

1from lets_plot import *
2LetsPlot.setup_html()
3x = list(range(9))
4ggplot({'x': x}, aes(x='x')) + \
5    geom_tile(aes(color='x', fill='x')) + \
6    scale_viridis(aesthetic=['color', 'fill'], option='twilight') + \
7    coord_cartesian() + \
8    ggsize(600, 200)