Introduction | Save a Plot in Matplotlib?

Basics of Saving a Plot in Matplotlib

Introduction

There are two ways to save plots as images in matplotlib, first by using savefig() and second by using the imsave() function. The savefig() function takes at least one parameter (filename) to save an image. The imsave() function takes at least two parameters file name and NumPy array of the coordinates of the rendered file. We can also change the visual appearance of the images before saving by passing some parameters like face color, edge color, and transparency. These functions save images to your local memory in formats like png, pdf, svg, etc.

Syntax

Method 1: savefig() Function

Method 2: imsave() Function

Parameters

Method 1: savefig() Function

Method 2: imsave() Function

How to Save a Plot in Matplotlib

To save a plot, we have to define a plot by plotting data on the graph before the matplotlib.pyplot.show(); we have to use the savefig() or imsave() function to save the plot as an image.

Using savefig() Function

First, we plot some data on the graph.

Output:

Code explanation:

• Importing the required modules.
• Storing the x-axis data points in the list x.
• Storing the y-axis data points in the list y.
• Then, plotting the coordinates using the function matplotlib.pyplot.plot().
• Then enabling the grid on the graph using matplotlib.pyplot.grid() function.
• Saving the images using the function matplotlib.pyplot.savefig() by passing the file name along with the extension.
• Displaying the plot by using matplotlib.pyplot.show() function.

Using the savefig() function in the code above, the plot is saved as an image in your local storage.

We can open the image and see the saved plot.

Using imsave() Function

imsave() is also used for saving graphs, charts, plots, etc., in matplotlib. It also takes at least two-parameter (file name and array) to save the plot as an image to your local memory. It isn't very easy to save the matplotlib plots using the imsave() function as this function takes two parameters. The first parameter is the file name in which we must pass a string ending with extensions like 'png', 'svg', 'jpg', etc. The second parameter is an array containing the data of the rendered image.

Below is the representation of how we can save plots as the image in matplotlib

Output:

Code Explanation:

• Importing the required modules.
• Creating a figure using the matplotlib.pyplot.figure() function.
• Taking x-axis data points and storing them in the list x1.
• Taking y-axis data points and storing them in the list y1.
• Then, plot line 1 on the figure using the matplotlib.pyplot.plot() function.
• Similarly, we plot line 2.
• For adding details to the plot add title, x-label, and y-label to the plot by using the function matplotlib.pyplot.title(), matplotlib.pyplot.xlabel() and matplotlib.pyplot.ylabel() functions respectively.
• make an agg figure using fig.canvas.draw().
• Converting the rendered figure into the numpy array and storing it in the list X.
• Saving the image using the function matplotlib.pyplot.imsave(), the figure's name is 'Figure2.png', and array X is the coordinates of the rendered figure.
• Displaying the plot using the matplotlib.pyplot.show() function.

Examples

Example 1: Storing the plot as an image using an absolute path

Output:

Example 2: Saving a plot as jpg

Output:

Example 3: Saving the plot as an image with high resolution

Before using the dpi parameter, we can see that the output image is unclear, as shown below.

Output:

The plot is saved as a high-resolution image after using the dpi.

Output:

Example 4: Changing the background of the image

We can change the image's background by specifying the facecolor parameter in the imsave() or savefig() function.

Output:

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