Python Bokeh – Plotting Multiple Polygons on a Graph

Bokeh is a Python interactive data visualization. It renders its plots using HTML and JavaScript. It targets modern web browsers for presentation providing elegant, concise construction of novel graphics with high-performance interactivity.
Bokeh can be used to plot multiple polygons on a graph. Plotting multiple polygons on a graph can be done using the multi_polygons() method of the plotting module.

plotting.figure.multi_polygons()

Syntax : multi_polygons(parameters)
Parameters : 

• xs : x-coordinates of the polygons
• ys : y-coordinates of the polygons
• fill_alpha : fill alpha values of the polygons
• fill_color : fill color values of the polygons
• hatch_alpha : hatch alpha values of the polygons, default is 1
• hatch_color : hatch color values of the polygons, default is black
• hatch_extra : hatch extra values of the polygons
• hatch_pattern : hatch pattern values of the polygons
• hatch_scale : hatch scale values of the polygons, default is 12
• hatch_weight : hatch weight values of the polygons, default is 1
• line_alpha : percentage value of line alpha, default is 1
• line_cap : value of line cap for the line, default is butt
• line_color : color of the line, default is black
• line_dash : value of line dash such as : solid, dashed, dotted, dotdash, dashdot [default is solid ]
• line_dash_offset : value of line dash offset, default is 0
• line_join : value of line join, default in bevel
• line_width : value of the width of the line, default is 1
• name : user-supplied name for the model
• tags : user-supplied values for the model

Other Parameters : 

• alpha : sets all alpha keyword arguments at once
• color : sets all color keyword arguments at once
• legend_field : name of a column in the data source that should be used
• legend_group : name of a column in the data source that should be used
• legend_label : labels the legend entry
• muted : determines whether the glyph should be rendered as muted or not, default is False
• name : optional user-supplied name to attach to the renderer
• source : user-supplied data source
• view : view for filtering the data source
• visible : determines whether the glyph should be rendered or not, default is True
• x_range_name : name of an extra range to use for mapping x-coordinates
• y_range_name : name of an extra range to use for mapping y-coordinates
• level : specifies the render level order for this glyph

Returns : an object of class GlyphRenderer 

Example 1 : In this example we will be using the default values for plotting the graph.

Python3

# importing the modules
from bokeh.plotting import figure, output_file, show

# file to save the model
output_file("gfg.html")

# instantiating the figure object
graph = figure(title = "Bokeh Multiple Polygons Graph")

# the points to be plotted
xs = [[[[0, 0, 1, 1]]]]
ys = [[[[3, 2, 2, 3]]]]

# plotting the graph
graph.multi_polygons(xs, ys)

# displaying the model
show(graph)

Output : 

Example 2 : In this example we will be plotting the multiple polygons with various other parameters

Python3

# importing the modules
from bokeh.plotting import figure, output_file, show

# file to save the model
output_file("gfg.html")

# instantiating the figure object
graph = figure(title = "Bokeh Multiple Polygons Graph")

# name of the x-axis
graph.xaxis.axis_label = "x-axis"

# name of the y-axis
graph.yaxis.axis_label = "y-axis"

# the points to be plotted
xs = [[[[0, 0, 1, 1]]],
      [[[2, 2, 4, 4], [2.5, 2.5, 3.5, 3.5]]],
      [[[2, 0, 4]]]]
ys = [[[[2.5, 0.5, 0.5, 2.5]]],
      [[[1, 0, 0, 1], [0.75, 0.25, 0.25, 0.75]]],
      [[[2, 0, 0]]]]

# color values of the polygons
color = ["red", "purple", "yellow"]

# fill alpha values of the polygons
fill_alpha = 0.5

# plotting the graph
graph.multi_polygons(xs, ys,
                     color = color,
                     fill_alpha = fill_alpha)

# displaying the model
show(graph)

Output :