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 librariesimport sysfrom PyQt5.QtWidgets import QDialog, QApplication, QPushButton, QVBoxLayoutfrom matplotlib.backends.backend_qt5agg import FigureCanvasQTAgg as FigureCanvasfrom matplotlib.backends.backend_qt5agg import NavigationToolbar2QT as NavigationToolbarimport matplotlib.pyplot as pltimport random # main window# which inherits QDialogclass 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 codeif __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_()) |
Output :
