# Matplotlib.axes.Axes.spy() in Python

• Last Updated : 13 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.

## matplotlib.axes.Axes.spy() Function

The Axes.spy() function in axes module of matplotlib library is also used to plot the sparsity pattern of a 2D array.It is also used to visualize the non-zero values of the array.

Syntax: Axes.spy(self, Z, precision=0, marker=None, markersize=None, aspect=’equal’, origin=’upper’, **kwargs

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

• Z : This parameter is the array which is to be plotted.
• precision : This parameter is used to determine whether any non-zero value is to be plotted or not.
• origin : This parameter place the [0, 0] index of the array in the upper left or lower left corner of the axes.
• aspect : This parameter is an optional and it is used to control the aspect ratio of the axes.

Returns: This returns the following:

• ret:This returns the AxesImage or Line2D. And it depend on style of plotting

Below examples illustrate the matplotlib.axes.Axes.spy() function in matplotlib.axes:

Example-1:

 `# Implementation of matplotlib function``import` `matplotlib.pyplot as plt``import` `numpy as np`` ` `fig, ax1 ``=` `plt.subplots()`` ` `x ``=` `np.random.randn(``20``, ``50``)``x[``12``, :] ``=` `0.``x[:, ``22``] ``=` `0.``ax1.spy(x)`` ` `plt.show()``ax1.set_title(``'matplotlib.axes.Axes.spy() Example'``)``plt.show()`

Output:

Example-2:

 `# Implementation of matplotlib function``import` `matplotlib.pyplot as plt``import` `numpy as np`` ` `fig, [(ax1, ax2), (ax3, ax4)] ``=` `plt.subplots(``2``, ``2``)`` ` `x ``=` `np.random.randn(``20``, ``50``)``x[``5``, :] ``=` `0.``x[:, ``12``] ``=` `0.`` ` `ax1.spy(x, markersize ``=` `4``)``ax2.spy(x, precision ``=` `0.2``, markersize ``=` `4``)`` ` `ax3.spy(x)``ax4.spy(x, precision ``=` `0.4``)`` ` `plt.show()``ax1.set_title(``'matplotlib.axes.Axes.spy() Example'``)``plt.show()`

Output:

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