How to Add Grid Lines in Matplotlib?

In this article, we’ll learn how to add gridlines in Matplotlib plots. Matplotlib is a python plotting library which provides an interactive environment for creating scientific plots and graphs. Let’s get right into the topic.

Steps to add grid lines to Matplot lib plots

Let’s now go over the steps to add grid lines to a Matplotlib plot.

1. Installing the module

Matplotlib –

pip install matplotlib

Pyplot –

The pyplot submodule contains the majority of Matplotlib’s functionality

Note: Compilers usually don’t have the ability to show graphs but in Python, we can make them compatible by adding a few lines of code:

import sys
import matplotlib
matplotlib.use('Agg')
# Matplotlib relies on a backend to render the plots and here ‘Agg’ is the default backend

import matplotlib.pyplot as pyt
# lines of code for plotting a graph

pyt.savefig(sys.stdout.buffer)
sys.stdout.flush()
# these two lines are used to avoid excess buffering and print the data without any delay and make sure the code works

Example:

import sys
import matplotlib
matplotlib.use('Agg')
# Matplotlib relies on a backend to render the plots and here ‘Agg’ is the default backend

import matplotlib.pyplot as pyt
import numpy as np

x = np.array([0, 10])
y = np.array([0, 200])

pyt.plot(x, y)

pyt.show()

pyt.savefig(sys.stdout.buffer)
sys.stdout.flush()

2. Adding Grid Lines to a plot

We can use the grid() function with Pyplot to add grid lines to a plot.

Example:

x = np.array([0,10])
y = np.array([0,200])
pyt.title("Sales of Ice Cream")    
# to represent the title on the plot

pyt.xlabel("Days")                      # to label the x-axis
pyt.ylabel("Customers")            # to label the y-axis
pyt.plot(x, y)
pyt.grid()
pyt.show()

3. Specify the Grid Lines to Display

Using the axis parameter in the grid() function, we can specify which grid lines to display. Permitted values are: ‘x’, ‘y’ or ‘both’. But the default is ‘both’ so we can avoid writing it.

Example:

• Display only x-axis grid lines:

pyt.grid(axis = ‘y’)

• Display only y-axis grid lines:

pyt.grid(axis = ‘x’)

4. Setting Line properties for the Grid

We can set the properties of the grid in various ways for color, style, etc.

We define the styling as : color= ’specify_color’, linestyle=’specify_linestyle’, linewidth= number, axis=’specify_axis(‘x’,’y’ or ‘both’)’

For example:

pyt.grid(color = 'red', linestyle = '--', linewidth = 0.75, axis='both')

Conclusion

That’s it for the tutorial! Hope you have learned well how to plot grid lines in Python and also various properties of grid lines possible using matplotlib library. Stay tuned to Ask Python for more such tutorials on Python.