In this article, we will discuss how to save multiple matplotlib figures in a single PDF file using Python. We can use the PdfPages class’s savefig() method to save multiple plots in a single pdf. Matplotlib plots can simply be saved as PDF files with the .pdf extension. This saves Matplotlib-generated figures in a single PDF file named Save multiple plots as PDF.pdf in the current working directory.
Installation
pip install matplotlib
Stepwise Implementation
To come up with a solution, we will follow a few steps.
Step 1: Import necessary files.
Python3
from matplotlib import pyplot as plt from matplotlib.backends.backend_pdf import PdfPages |
Step 2: Set up the figure size and adjust the padding between and around the subplots.
Python3
plt.rcParams["figure.figsize"] = [7.00, 3.50] plt.rcParams["figure.autolayout"] = True |
Step 3: We will consider 3 plots, so let’s name them fig1, fig2, and fig3 using plt.figure().
Python3
fig1 = plt.figure() fig2 = plt.figure() Fig3 = plt.figure() |
Step 4: Plot the first line using the plt.plot() method.
Python3
plt.plot([17, 45, 7, 8, 7], color='orange') plt.plot([13, 25, 1, 6, 3], color='blue') plt.plot([22, 11, 2, 1, 23], color='green') |
Step 5: Create a function to save multiple images in a PDF file let’s say save_image().
Python3
def save_image(filename): # PdfPages is a wrapper around pdf # file so there is no clash and # create files with no error. p = PdfPages(filename) # get_fignums Return list of existing # figure numbers fig_nums = plt.get_fignums() figs = [plt.figure(n) for n in fig_nums] # iterating over the numbers in list for fig in figs: # and saving the files fig.savefig(p, format='pdf') # close the object p.close() |
Complete Code
Python3
import matplotlib from matplotlib import pyplot as plt from matplotlib.backends.backend_pdf import PdfPages # customizing runtime configuration stored # in matplotlib.rcParams plt.rcParams["figure.figsize"] = [7.00, 3.50] plt.rcParams["figure.autolayout"] = True fig1 = plt.figure() plt.plot([17, 45, 7, 8, 7], color='orange') fig2 = plt.figure() plt.plot([13, 25, 1, 6, 3], color='blue') Fig3 = plt.figure() plt.plot([22, 11, 2, 1, 23], color='green') def save_image(filename): # PdfPages is a wrapper around pdf # file so there is no clash and create # files with no error. p = PdfPages(filename) # get_fignums Return list of existing # figure numbers fig_nums = plt.get_fignums() figs = [plt.figure(n) for n in fig_nums] # iterating over the numbers in list for fig in figs: # and saving the files fig.savefig(p, format='pdf') # close the object p.close() # name your Pdf file filename = "multi_plot_image.pdf" # call the function save_image(filename) |
Output:
Now after you run the code you can see on your local directory that a pdf containing all three plots will be saved in a pdf named “multi_plot_image.pdf”.
