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. The Axes.semilogy() function in axes module of matplotlib library is used to make a plot with log scaling on the y axis.

Syntax:

Axes.semilogy(self, *args, **kwargs)

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

• basey: This parameter is the base of the y logarithm and are optional with default value 10.
• subsy: This parameter is the sequence of location of the minor y ticks and is optional.
• nonposy: This parameter is a non-positive values in y that can be masked as invalid, or clipped to a very small positive number.

Returns: This returns the following:

• lines:This returns the list of Line2D objects representing the plotted data..

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

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

test = np.arange(0.01, 30.0, 0.1)

# Create figure
fig, ax = plt.subplots()


# log x axis
ax.semilogy(test, np.exp(-test / 5.0))
ax.grid()


ax.set_title('matplotlib.axes.Axes.semilogy Example1')
plt.show()

Output: Example-2:

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

test = np.arange(0.01, 30.0, 0.1)

# Create figure
fig, ax = plt.subplots()


# log x axis
ax.semilogy(test, np.sin(3 * np.pi * test))
ax.grid()


ax.set_title('matplotlib.axes.Axes.semilogy Example2')
plt.show()

Output: