# Change matplotlib line style in mid-graph

• Last Updated : 12 Nov, 2020

Prerequisite: Matplotlib

In this article we will learn how to change line style in mid-graph using matplotlib in Python.

• Matplotlib: It is a tremendous visualization library in Python for 2D plots of arrays. Matplotlib may be a multi-platform data visualization library built on NumPy arrays and designed to figure with the broader SciPy stack. It was introduced by John Hunter within the year 2002.
• Line style: Line style is a feature that describes in which fashion or style line is drawn. Following image shows the key that has to provided as input parameter and what line style it will produce:

Approach:

1. Import the matplotlib.pyplot library and other for data (optional)
2. Import or create some data
3. Draw a graph plot with different line style is middle.

Example 1:

In this example we will use simple steps mentioned above and form a graph with two different line styles.

## Python3

 `# importing packages``import` `matplotlib.pyplot as plt``import` `numpy as np`` ` `# create data``x ``=` `np.linspace(``0``, ``10``, ``100``)``y ``=` `3` `*` `x ``+` `2`` ` `below ``=` `y < ``15``above ``=` `y >``=` `15`` ` `# Plot lines below as dotted-------``plt.plot(x[below], y[below], ``'--'``)`` ` `# Plot lines above as solid________``plt.plot(x[above], y[above], ``'-'``)`` ` `plt.show()`

Output :

Example 2 :

In this example we will use simple steps mentioned above and form a graph with two different line styles in one sine function.

## Python3

 `# importing packages``import` `matplotlib.pyplot as plt``import` `numpy as np`` ` `# create data``x ``=` `np.linspace(``0``, ``10``, ``100``)``y ``=` `np.sin(x)`` ` `below ``=` `y < .``5``above ``=` `y >``=` `.``5`` ` `# Plot lines below as dotted-------``plt.plot(x[below], y[below], ``'--'``)`` ` `# Plot lines above as solid_______``plt.plot(x[above], y[above], ``'-'``)`` ` `plt.show()`

Output :

Example 3 :

This is similar to above example with extra cosine function to show different feature of line styles in mid graph.

## Python3

 `# importing packages``import` `matplotlib.pyplot as plt``import` `numpy as np`` ` `# create data``x ``=` `np.linspace(``0``, ``10``, ``100``)``y1 ``=` `np.sin(x)``y2 ``=` `np.cos(x)`` ` `below ``=` `abs``(y1``-``y2) < .``2``above ``=` `abs``(y1``-``y2) >``=` `.``2`` ` `# Plot lines below as dotted-------``plt.plot(x[below], y1[below], ``'r--'``)`` ` `# Plot lines below as dotted-------``plt.plot(x[below], y2[below], ``'g--'``)`` ` `# Plot lines above as solid_______``plt.plot(x[above], y1[above], ``'r-'``)`` ` `# Plot lines above as solid_______``plt.plot(x[above], y2[above], ``'g-'``)`` ` `plt.show()`

Output :

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