geom_function#

geom_function(mapping=None, *, data=None, stat=None, geom=None, position=None, show_legend=None, inherit_aes=None, manual_key=None, tooltips=None, fun=None, xlim=None, n=None, color_by=None, **other_args)#

Compute and draw a function.

Parameters:
mappingFeatureSpec

Set of aesthetic mappings created by aes() function. Aesthetic mappings describe the way that variables in the data are mapped to plot “aesthetics”.

datadict or Pandas or Polars DataFrame

The data to be used in this layer. Specify to describe the definition area of a function. If None, the default, the data will not be used at all.

statstr, default=’identity’

The statistical transformation to use on the data generated by the function. Supported transformations: ‘identity’ (leaves the data unchanged), ‘smooth’ (performs smoothing - linear default), ‘density2d’ (computes and draws 2D kernel density estimate).

geomstr, default=’line’

The geometry to display the function, as a string.

positionstr or FeatureSpec, default=’identity’

Position adjustment. Either a position adjustment name: ‘dodge’, ‘dodgev’, ‘jitter’, ‘nudge’, ‘jitterdodge’, ‘fill’, ‘stack’ or ‘identity’, or the result of calling a position adjustment function (e.g., position_dodge() etc.).

show_legendbool, default=True

False - do not show legend for this layer.

inherit_aesbool, default=True

False - do not combine the layer aesthetic mappings with the plot shared mappings.

manual_keystr or layer_key

The key to show in the manual legend. Specify text for the legend label or advanced settings using the layer_key() function.

tooltipslayer_tooltips

Result of the call to the layer_tooltips() function. Specify appearance, style and content. Set tooltips=’none’ to hide tooltips from the layer.

funfunction

A function of one variable in Python syntax.

xlimlist of float, default=[0.0, 1.0]

Range of the function. Float array of length 2.

nint, default=512

Number of points to interpolate along the x axis.

color_by{‘fill’, ‘color’, ‘paint_a’, ‘paint_b’, ‘paint_c’}, default=’color’

Define the color aesthetic for the geometry.

other_args

Other arguments passed on to the layer. These are often aesthetics settings used to set an aesthetic to a fixed value, like color=’red’, fill=’blue’, size=3 or shape=21. They may also be parameters to the paired geom/stat.

Returns:
LayerSpec

Geom object specification.

Notes

geom_function() understands the following aesthetics mappings:

  • x : x-axis value.

  • alpha : transparency level of a layer. Accept values between 0 and 1.

  • color (colour) : color of the geometry. For more info see Color and Fill.

  • linetype : type of the line. Accept codes or names (0 = ‘blank’, 1 = ‘solid’, 2 = ‘dashed’, 3 = ‘dotted’, 4 = ‘dotdash’, 5 = ‘longdash’, 6 = ‘twodash’), a hex string (up to 8 digits for dash-gap lengths), or a list pattern [offset, [dash, gap, …]] / [dash, gap, …]. For more info see Line Types.

  • size : line width.


To hide axis tooltips, set ‘blank’ or the result of element_blank() to the axis_tooltip, axis_tooltip_x or axis_tooltip_y parameter of the theme().

Examples

1import numpy as np
2from scipy.stats import norm
3from lets_plot import *
4LetsPlot.setup_html()
5np.random.seed(42)
6x = np.random.normal(size=500)
7ggplot() + \
8    geom_density(aes(x='x'), data={'x': x}) + \
9    geom_function(fun=norm.pdf, xlim=[-4, 4], color="red")

1from lets_plot import *
2LetsPlot.setup_html()
3data = {'x': list(range(-5, 6))}
4ggplot() + \
5    geom_function(aes(x='x', color='y', size='y'), \
6                  data=data, fun=lambda t: t**2, show_legend=False) + \
7    scale_color_gradient(low="red", high="green") + \
8    scale_size(range=[1, 4], trans='reverse')

 1from math import sqrt
 2from lets_plot import *
 3LetsPlot.setup_html()
 4fun_layer = lambda fun: geom_function(fun=fun, xlim=[-2, 2], n=9, \
 5                                      stat='density2d', geom='density2d')
 6gggrid([
 7    ggplot() + fun_layer(lambda t: t),
 8    ggplot() + fun_layer(lambda t: t**2),
 9    ggplot() + fun_layer(lambda t: 2**t),
10    ggplot() + fun_layer(lambda t: sqrt(4 - t**2)) + coord_fixed(ratio=2),
11], ncol=2)