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MatPlotLib

Matplotlib is a comprehensive library for creating static, animated, and interactive visualizations.

Install​

pip install matplotlib

Introduction to pyplot​

matplotlib.pyplot is a collection of functions that make matplotlib work like MATLAB. Each pyplot function makes some change to a figure: e.g., creates a figure, creates a plotting area in a figure, plots some lines in a plotting area, decorates the plot with labels, etc.

note

In matplotlib.pyplot various states are preserved across function calls, so that it keeps track of things like the current figure and plotting area, and the plotting functions are directed to the current axes (please note that "axes" here and in most places in the documentation refers to the axes part of a figure and not the strict mathematical term for more than one axis).

Generating Visualizations with pyplot is very quick:

HelloWorld.py
import matplotlib.pyplot as plt

plt.plot([1, 2, 3, 4])
plt.ylabel('some numbers')
plt.show()

The Graph for the above code is:

Graph

You may be wondering why the x-axis ranges from 0-3 and the y-axis from 1-4. If you provide a single list or array to plot, matplotlib assumes it is a sequence of y values, and automatically generates the x values for you. Since python ranges start with 0, the default x vector has the same length as y but starts with 0; therefore, the x data are [0, 1, 2, 3].

Plot is a versatile function, and will take an arbitrary number of arguments. For example, to plot x versus y, you can write:

HelloWorld.py
plt.plot([1, 2, 3, 4], [1, 4, 9, 16])

Graph1