Matplotlib - Hyperlinks

A hyperlink, often referred to as a link, is a navigational element that present in various forms, such as text, images, icons, or buttons, within a document or on a webpage. When clicked or activated, a hyperlink redirects the user to a specified URL or resource, creating a seamless and interactive experience.

Matplotlib provides a variety of tools to include hyperlinks in plots. In this tutorial, you will explore how to add hyperlinks in Matplotlib plots, such as SVG figures and PdfPages.

Creating SVG figures with hyperlinks

SVG (known as Scalable Vector Graphics) is an XML-based image format that supports hyperlinks. However, it's crucial to note that hyperlinks in Matplotlib specifically apply to SVG output. If the plot is saved as a static image, such as PNG or JPEG, or is displayed as plot in a window, the hyperlink functionality will not be operational.

In such case, you can use this feature in interactive plots with clickable elements.

Example

In this example, a scatter plot is created, and hyperlinks are assigned to individual data points using the set_urls method.

import matplotlib.pyplot as plt
import numpy as np

fig = plt.figure()
s = plt.scatter([1, 2, 3], [4, 5, 6])
s.set_urls(['https://www.tutorialspoint.com', 'https://www.tutorialspoint.com/matplotlib/index.htm', None])
fig.savefig('scatter.svg')

Output

After running the above code, you can check the output directory for the .svg image file.

hyperlinks_ex1 GIF

Adding Hyperlinks in PdfPages

The PdfPages module in matplotlib enables the creation of multipage PDF documents. You can add hyperlinks to those pdf pages using the matplotlib text elements.

Example

In this example, a PDF document is created using PdfPages, and a text element with a hyperlink is added to the plot.

import matplotlib.pyplot as plt
from matplotlib.backends.backend_pdf import PdfPages

msr_line4 = r'$\bf{' + 'Tutorialspoint\ Matplotlib\ Resource : ' + '}$' + "https://www.tutorialspoint.com/matplotlib/index.htm"
with PdfPages('Adding_hyperlink_inside_a_PdfPage.pdf') as pdf:
   plt.figure(figsize=(11, 8.5))

   ax2 = plt.subplot2grid((9, 5), (1, 0), rowspan=1, colspan=2)
   ax2.text(0, 0, msr_line4, fontsize=9)
   plt.axis('off')
   pdf.savefig()
   plt.close

Output

After running the above code, you can check the output directory for the .pdf file.

hyperlinks_ex2 GIF

Hyperlinks in Interactive Plots

For plots that are not rendered as SVG, such as interactive plots displayed in a Matplotlib window, hyperlinks can be implemented using event handlers. By creating a function to handle the "pick" event, you can define actions to be taken when specific elements, like data points, are clicked.

Example

The following example demonstrates how to open a specified hyperlink in a web browser when clicking on a data point.

import matplotlib.pyplot as plt
import webbrowser

class CustomObject:
   def __init__(self, x, y, name):
      self.x = x
      self.y = y
      self.name = name

def on_pick(event):
   webbrowser.open('https://www.tutorialspoint.com')

# Create custom objects
obj_a = CustomObject(0.1, 0.3, "Object A")
obj_b = CustomObject(0.2, 0.5, "Object B")

# Plotting objects with picker attribute
fig, ax = plt.subplots()
for obj in [obj_a, obj_b]:
   artist = ax.plot(obj.x, obj.y, 'ro', picker=10)[0]
   artist.obj = obj

# Connect pick event to the handler
fig.canvas.callbacks.connect('pick_event', on_pick)

plt.show()

Output

See the below video for how the output looks like.

hyperlinks_ex3 gif
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