Violinplot in Python using axes class of Matplotlib

Last Updated : 21 Apr, 2020

Matplotlib is a library in Python and it is numerical - mathematical extension for NumPy library. The Axes Class contains most of the figure elements: Axis, Tick, Line2D, Text, Polygon, etc., and sets the coordinate system. And the instances of Axes supports callbacks through a callbacks attribute. #Sample Code

# Implementation of matplotlib function
    
import matplotlib.pyplot as plt
import numpy as np
  
# make an agg figure
fig, ax = plt.subplots()
ax.plot([1, 2, 3])
ax.set_title('matplotlib.axes.Axes function')
fig.canvas.draw()
plt.show()

Output:

Violinplot using Axes Class

The Axes.violinplot() function in axes module of matplotlib library is used to make a violin plot for each column of dataset or each vector in sequence dataset. Syntax:

Axes.violinplot(self, dataset, positions=None, vert=True, widths=0.5, showmeans=False, showextrema=True, showmedians=False, points=100, bw_method=None, *, data=None)

Parameters: This method accept the following parameters that are described below:

dataset: This parameter is a sequence of data.
positions : This parameter is used to sets the positions of the violins.
vert: This parameter is an optional parameter and contain boolean value. It makes the vertical violin plot if true.Otherwise horizontal.
widths: This parameter is used to sets the width of each violin either with a scalar or a sequence.
showmeans : This parameter contain boolean value. It is used to toggle rendering of the means.
showextrema : This parameter contain boolean value. It is used to toggle rendering of the extrema.
showmedians : This parameter contain boolean value. It is used to toggle rendering of the medians.
points : This parameter is used to defines the number of points to evaluate each of the gaussian kernel density estimations at.

Returns: This returns the following:

result :This returns the dictionary which maps each component of the violinplot to a list of the matplotlib.collections instances.

Below examples illustrate the matplotlib.axes.Axes.violinplot() function in matplotlib.axes: Example-1:

# Implementation of matplotlib function
import matplotlib.pyplot as plt
import numpy as np

# create test data
np.random.seed(10**7)
data = np.random.normal(0, 5, 100)

fig, ax1 = plt.subplots()
val = ax1.violinplot(data)
 
ax1.set_title('matplotlib.axes.Axes.violinplot() Example')
plt.show()

Output:

Example-2:

# Implementation of matplotlib function
import matplotlib.pyplot as plt
import numpy as np

# create test data
np.random.seed(10**7)
data = [sorted(np.random.normal(0, std, 100)) for std in range(1, 5)]

fig, ax1 = plt.subplots()
val = ax1.violinplot(data)
ax1.set_ylabel('Result')
ax1.set_xlabel('Domain Name')
for i in val['bodies']:
    i.set_facecolor('green')
    i.set_alpha(1)
 
ax1.set_title('matplotlib.axes.Axes.violinplot() Example')
plt.show()