Python Bokeh – Plotting Ellipses on a Graph

Last Updated : 03 Jul, 2020

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 ellipses on a graph. Plotting ellipses on a graph can be done using the ellipse() method of the plotting module.

plotting.figure.ellipse()

Syntax : ellipse(parameters)

Parameters :

x : x-coordinates of the center of the ellipse

y : y-coordinates of the center of the ellipse

width : width of each ellipse

height : height of each ellipse

angle : angle of rotation of the ellipse, default is 0

angle_units : unit of the angle, default is rad

fill_alpha : fill alpha value of the ellipse

fill_color : fill color value of the ellipse

height_units : unit of the height, default isdata

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.

# 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 Ellipse Graph", 
               match_aspect = True) 
    
# the points to be plotted 
x = 0
y = 0
  
# width of the ellipse 
width = 60
  
# height of the ellipse 
height = 20
  
# plotting the graph 
graph.ellipse(x, y, 
              width = width, 
              height = height) 
   
# displaying the model 
show(graph) 

Output :

Example 2 :In this example we will be plotting multiple ellipses with different parameters.

# 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 Ellipse 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 
x = [0, 30, 0] 
y = [0, 30, -30] 
  
# width of the ellipse 
width = [60, 20, 40] 
  
# height of the ellipse 
height = [20, 180, 80] 
  
# angle of the ellipse 
angle = [0, 150, 20] 
  
# fill alpha values 
fill_alpha = 0.3
  
# fill color values 
fill_color = ["red", "yellow", "blue"] 
  
# line color value 
line_color = "black"
  
# plotting the graph 
graph.ellipse(x, y, 
              width = width, 
              height = height, 
              angle = angle, 
              fill_alpha = fill_alpha, 
              fill_color = fill_color, 
              line_color = line_color) 
   
# displaying the model 
show(graph) 