Python Bokeh – Plotting Ovals 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 ovals on a graph. Plotting ovals on a graph can be done using the oval() method of the plotting module.

plotting.figure.oval()

Syntax : oval(parameters)

Parameters :

• x : x-coordinates of the center of the oval markers
• y : y-coordinates of the center of the oval markers
• width : width of the oval markers
• height : height of the oval markers
• width_units : unit of the width of the oval markers
• height_units : unit of the height of the oval markers
• angle : angle of rotation of the oval markers, default is 0
• angle_units : unit of the angle, default is rad
• fill_alpha : fill alpha value of the oval markers
• fill_color : fill color value of the oval markers
• 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 Oval Graph")

# the points to be plotted
x = [-5, -4, -3, -2, -1, 0, 1, 2, 3, 4, 5]
y = [i ** 2 for i in x]

# plotting the graph
graph.oval(x, y,
           height = 0.5,
           width = 1)

# displaying the model
show(graph)

Output :

Example 2 : In this example we will be plotting the ovals with dotted lines alongside other parameters and the size of the hexagons are in proportion to their values.

# 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 Oval 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 = [-5, -4, -3, -2, -1, 0, 1, 2, 3, 4, 5]
y = [i ** 2 for i in x]

# width of the ovals
height = [i * 2 for i in y]

# angle of the ovals
width = [i * 2.5 for i in y]

# angle of the ovals
angle = 10

# fill color value
fill_color = None

# color of the line
line_color = "red"

# type of line
line_dash = "dotted"

# offset of line dash
line_dash_offset = 1

# width of the dashes
line_width = 10

# name of the legend
legend_label = "Sample Ovals"

# plotting the graph
graph.oval(x, y,
          height = height,
          width = width,
          angle = angle,
          fill_color = fill_color,
          line_color = line_color,
          line_dash = line_dash,
          line_dash_offset = line_dash_offset,
          line_width = line_width,
          legend_label = legend_label)


# displaying the model
show(graph)

Output :