Embedding matplotlib plot on PyQt5 GUI!

Introduction

Embedding matplotlib plot on PyQt GUI or some other python GUI library's is noting new when it comes to examples provided by various authors across the web and examples provided in matplotlib documentation. But as you can see there is no example for embedding matplotlib plot in PyQt5. I wanted to make some small app for my android device and needed plot as part of my application. You can do this with PySide, and I encourage you to do so if you want to make commercial app, for me this was not the case, my app is for my own purpose and at some point I might switch from android to iOS device. Remember that PySide is not going to work on iOS devices while PyQt5 will.

Prerequisites

Like in previous python samples I will use Python 3. All things you need for this:

I'm not sure but previous versions of matplolib don't support PyQt5.

Matplolib example for PyQt4 from documentation

While trying to figure out how to do this task, best way was to start with Matplotlib documentation example for embedding plot in PyQt4 GUI. This is the code from that script:

#!/usr/bin/env python

# embedding_in_qt4.py --- Simple Qt4 application embedding matplotlib canvases
#
# Copyright (C) 2005 Florent Rougon
#               2006 Darren Dale
#
# This file is an example program for matplotlib. It may be used and
# modified with no restriction; raw copies as well as modified versions
# may be distributed without limitation.

from __future__ import unicode_literals
import sys
import os
import random
from matplotlib.backends import qt4_compat
use_pyside = qt4_compat.QT_API == qt4_compat.QT_API_PYSIDE
if use_pyside:
    from PySide import QtGui, QtCore
else:
    from PyQt4 import QtGui, QtCore

from numpy import arange, sin, pi
from matplotlib.backends.backend_qt4agg import FigureCanvasQTAgg as FigureCanvas
from matplotlib.figure import Figure

progname = os.path.basename(sys.argv[0])
progversion = "0.1"


class MyMplCanvas(FigureCanvas):
    """Ultimately, this is a QWidget (as well as a FigureCanvasAgg, etc.)."""
    def __init__(self, parent=None, width=5, height=4, dpi=100):
        fig = Figure(figsize=(width, height), dpi=dpi)
        self.axes = fig.add_subplot(111)
        # We want the axes cleared every time plot() is called
        self.axes.hold(False)

        self.compute_initial_figure()

        #
        FigureCanvas.__init__(self, fig)
        self.setParent(parent)

        FigureCanvas.setSizePolicy(self,
                QtGui.QSizePolicy.Expanding,
                QtGui.QSizePolicy.Expanding)
        FigureCanvas.updateGeometry(self)

    def compute_initial_figure(self):
        pass


class MyStaticMplCanvas(MyMplCanvas):
    """Simple canvas with a sine plot."""
    def compute_initial_figure(self):
        t = arange(0.0, 3.0, 0.01)
        s = sin(2*pi*t)
        self.axes.plot(t, s)


class MyDynamicMplCanvas(MyMplCanvas):
    """A canvas that updates itself every second with a new plot."""
    def __init__(self, *args, **kwargs):
        MyMplCanvas.__init__(self, *args, **kwargs)
        timer = QtCore.QTimer(self)
        timer.timeout.connect(self.update_figure)
        timer.start(1000)

    def compute_initial_figure(self):
        self.axes.plot([0, 1, 2, 3], [1, 2, 0, 4], 'r')

    def update_figure(self):
        # Build a list of 4 random integers between 0 and 10 (both inclusive)
        l = [random.randint(0, 10) for i in range(4)]

        self.axes.plot([0, 1, 2, 3], l, 'r')
        self.draw()


class ApplicationWindow(QtGui.QMainWindow):
    def __init__(self):
        QtGui.QMainWindow.__init__(self)
        self.setAttribute(QtCore.Qt.WA_DeleteOnClose)
        self.setWindowTitle("application main window")

        self.file_menu = QtGui.QMenu('&File', self)
        self.file_menu.addAction('&Quit', self.fileQuit,
                QtCore.Qt.CTRL + QtCore.Qt.Key_Q)
        self.menuBar().addMenu(self.file_menu)

        self.help_menu = QtGui.QMenu('&Help', self)
        self.menuBar().addSeparator()
        self.menuBar().addMenu(self.help_menu)

        self.help_menu.addAction('&About', self.about)

        self.main_widget = QtGui.QWidget(self)

        l = QtGui.QVBoxLayout(self.main_widget)
        sc = MyStaticMplCanvas(self.main_widget, width=5, height=4, dpi=100)
        dc = MyDynamicMplCanvas(self.main_widget, width=5, height=4, dpi=100)
        l.addWidget(sc)
        l.addWidget(dc)

        self.main_widget.setFocus()
        self.setCentralWidget(self.main_widget)

        self.statusBar().showMessage("All hail matplotlib!", 2000)

    def fileQuit(self):
        self.close()

    def closeEvent(self, ce):
        self.fileQuit()

    def about(self):
        QtGui.QMessageBox.about(self, "About",
  """embedding_in_qt4.py example
  Copyright 2005 Florent Rougon, 2006 Darren Dale

  This program is a simple example of a Qt4 application embedding matplotlib
  canvases.

  It may be used and modified with no restriction; raw copies as well as
  modified versions may be distributed without limitation."""
  )


qApp = QtGui.QApplication(sys.argv)

aw = ApplicationWindow()
aw.setWindowTitle("%s" % progname)
aw.show()
sys.exit(qApp.exec_())
#qApp.exec_()

Changes needed for this code to run on with PyQt5 are minimal.

Matplotlib example for PyQt5

First lets adjust imports to port from PyQt4 to PyQt5, and get rid of some not needed code:

import sys
import random
import matplotlib
matplotlib.use("Qt5Agg")
from PyQt5 import QtCore
from PyQt5.QtWidgets import QApplication, QMainWindow, QMenu, QVBoxLayout, QSizePolicy, QMessageBox, QWidget
from numpy import arange, sin, pi
from matplotlib.backends.backend_qt5agg import FigureCanvasQTAgg as FigureCanvas
from matplotlib.figure import Figure

The main GUI elements are in QtWidgets module, unlike in PyQt4 they are in QtGui module. For more information see Differences Between PyQt4 and PyQt5.

Also you will need to enable matplotlib to use Qt5Agg backend, line setting this up is:

matplolib.use('Qt5Agg')  

Other changes in code are minor and basically are changes from QtGui to QtWidgets module, also I have deleted some not needed stuff to keep it simple. Whole code is:

import sys
import random
import matplotlib
matplotlib.use("Qt5Agg")
from PyQt5 import QtCore
from PyQt5.QtWidgets import QApplication, QMainWindow, QMenu, QVBoxLayout, QSizePolicy, QMessageBox, QWidget
from numpy import arange, sin, pi
from matplotlib.backends.backend_qt5agg import FigureCanvasQTAgg as FigureCanvas
from matplotlib.figure import Figure


class MyMplCanvas(FigureCanvas):
    """Ultimately, this is a QWidget (as well as a FigureCanvasAgg, etc.)."""
    def __init__(self, parent=None, width=5, height=4, dpi=100):
        fig = Figure(figsize=(width, height), dpi=dpi)
        self.axes = fig.add_subplot(111)
        # We want the axes cleared every time plot() is called
        self.axes.hold(False)

        self.compute_initial_figure()

        #
        FigureCanvas.__init__(self, fig)
        self.setParent(parent)

        FigureCanvas.setSizePolicy(self,
                QSizePolicy.Expanding,
                QSizePolicy.Expanding)
        FigureCanvas.updateGeometry(self)

  def compute_initial_figure(self):
        pass

class MyStaticMplCanvas(MyMplCanvas):
    """Simple canvas with a sine plot."""
    def compute_initial_figure(self):
        t = arange(0.0, 3.0, 0.01)
        s = sin(2*pi*t)
        self.axes.plot(t, s)


class MyDynamicMplCanvas(MyMplCanvas):
  """A canvas that updates itself every second with a new plot."""
    def __init__(self, *args, **kwargs):
        MyMplCanvas.__init__(self, *args, **kwargs)
        timer = QtCore.QTimer(self)
        timer.timeout.connect(self.update_figure)
        timer.start(1000)

    def compute_initial_figure(self):
        self.axes.plot([0, 1, 2, 3], [1, 2, 0, 4], 'r')

    def update_figure(self):
        # Build a list of 4 random integers between 0 and 10 (both inclusive)
        l = [random.randint(0, 10) for i in range(4)]

        self.axes.plot([0, 1, 2, 3], l, 'r')
        self.draw()

class ApplicationWindow(QMainWindow):
    def __init__(self):
        QMainWindow.__init__(self)
        self.setAttribute(QtCore.Qt.WA_DeleteOnClose)
        self.setWindowTitle("application main window")

        self.file_menu = QMenu('&File', self)
        self.file_menu.addAction('&Quit', self.fileQuit,
                QtCore.Qt.CTRL + QtCore.Qt.Key_Q)
        self.menuBar().addMenu(self.file_menu)

        self.help_menu = QMenu('&Help', self)
        self.menuBar().addSeparator()
        self.menuBar().addMenu(self.help_menu)

        self.help_menu.addAction('&About', self.about)

        self.main_widget = QWidget(self)

        l = QVBoxLayout(self.main_widget)
        sc = MyStaticMplCanvas(self.main_widget, width=5, height=4, dpi=100)
        dc = MyDynamicMplCanvas(self.main_widget, width=5, height=4, dpi=100)
        l.addWidget(sc)
        l.addWidget(dc)

        self.main_widget.setFocus()
        self.setCentralWidget(self.main_widget)

        self.statusBar().showMessage("All hail matplotlib!", 2000)

    def fileQuit(self):
        self.close()

    def closeEvent(self, ce):
        self.fileQuit()

    def about(self):
        QMessageBox.about(self, "About",
  """embedding_in_qt5.py example
  Copyright 2015 BoxControL

  This program is a simple example of a Qt5 application embedding matplotlib
  canvases. It is base on example from matplolib documentation, and initially was
  developed from Florent Rougon and Darren Dale.

  http://matplotlib.org/examples/user_interfaces/embedding_in_qt4.html

  It may be used and modified with no restriction; raw copies as well as
  modified versions may be distributed without limitation."""
  )

if __name__ == '__main__':
    app = QApplication(sys.argv)

    aw = ApplicationWindow()
    aw.setWindowTitle("PyQt5 Matplot Example")
    aw.show()
    #sys.exit(qApp.exec_())
    app.exec_()

Here is the screenshot of application:

alt text

full code can be found on github

Comments !

social