How to Embed Matplotlib Graph in PyQt5?

Last Updated : 20 Jan, 2022

In this article, we will see how we can plot the graphs in the PyQt5 window using matplotlib.
Matplotlib is an amazing visualization library in Python for 2D plots of arrays. Matplotlib is a multi-platform data visualization library built on NumPy arrays and designed to work with the broader SciPy stack. It was introduced by John Hunter in the year 2002.
PyQt5 is cross-platform GUI toolkit, a set of Python bindings for Qt v5. One can develop an interactive desktop application with so much ease because of the tools and simplicity provided by this library. A GUI application consists of Front-end and Back-end.

Getting Started

In order to plot graphs using Matplotlib in PyQt5 we need FigureCanvasQTAgg and NavigationToolbar2QT these are similar to the PyQt5 widgets these are embedding.

NavigationToolbar2QT : It will provide the tool bar for the graph, It can be imported with the help of command given below

from matplotlib.backends.backend_qt5agg import NavigationToolbar2QT as NavigationToolbar

FigureCanvasQTAgg : It will provide the canvas for the graph, It can be imported with the help of command given below

from matplotlib.backends.backend_qt5agg import FigureCanvasQTAgg as FigureCanvas

Below is how FigureCanvasQTAgg and NavigationToolbar2QT looks like –

Below is the implementation

Python3

# importing various libraries
import sys
from PyQt5.QtWidgets import QDialog, QApplication, QPushButton, QVBoxLayout
from matplotlib.backends.backend_qt5agg import FigureCanvasQTAgg as FigureCanvas
from matplotlib.backends.backend_qt5agg import NavigationToolbar2QT as NavigationToolbar
import matplotlib.pyplot as plt
import random
  
# main window
# which inherits QDialog
class Window(QDialog):
      
    # constructor
    def __init__(self, parent=None):
        super(Window, self).__init__(parent)
  
        # a figure instance to plot on
        self.figure = plt.figure()
  
        # this is the Canvas Widget that 
        # displays the 'figure'it takes the
        # 'figure' instance as a parameter to __init__
        self.canvas = FigureCanvas(self.figure)
  
        # this is the Navigation widget
        # it takes the Canvas widget and a parent
        self.toolbar = NavigationToolbar(self.canvas, self)
  
        # Just some button connected to 'plot' method
        self.button = QPushButton('Plot')
          
        # adding action to the button
        self.button.clicked.connect(self.plot)
  
        # creating a Vertical Box layout
        layout = QVBoxLayout()
          
        # adding tool bar to the layout
        layout.addWidget(self.toolbar)
          
        # adding canvas to the layout
        layout.addWidget(self.canvas)
          
        # adding push button to the layout
        layout.addWidget(self.button)
          
        # setting layout to the main window
        self.setLayout(layout)
  
    # action called by the push button
    def plot(self):
          
        # random data
        data = [random.random() for i in range(10)]
  
        # clearing old figure
        self.figure.clear()
  
        # create an axis
        ax = self.figure.add_subplot(111)
  
        # plot data
        ax.plot(data, '*-')
  
        # refresh canvas
        self.canvas.draw()
  
# driver code
if __name__ == '__main__':
      
    # creating apyqt5 application
    app = QApplication(sys.argv)
  
    # creating a window object
    main = Window()
      
    # showing the window
    main.show()
  
    # loop
    sys.exit(app.exec_())