How to plot on my GUI

Question

I'm designing a GUI with PyQt where I need to display a matplotlib/pylab window when I click on a button that makes the plot of the data from a function I've created. It's like a runtime used in Matlab. I want to keep the matplotlib/pylab window as my window everytime I press that button.

Answer 1

Here is a basic example that will plot three different samples using a QThread:

#!/usr/bin/env python
#-*- coding:utf-8 -*-

import random

from matplotlib.backends.backend_qt4agg import FigureCanvasQTAgg
from matplotlib.figure import Figure

from PyQt4 import QtGui, QtCore

class MatplotlibWidget(QtGui.QWidget):
    def __init__(self, parent=None):
        super(MatplotlibWidget, self).__init__(parent)

        self.figure = Figure()
        self.canvas = FigureCanvasQTAgg(self.figure)

        self.axis = self.figure.add_subplot(111)

        self.layoutVertical = QtGui.QVBoxLayout(self)
        self.layoutVertical.addWidget(self.canvas)

class ThreadSample(QtCore.QThread):
    newSample = QtCore.pyqtSignal(list)

    def __init__(self, parent=None):
        super(ThreadSample, self).__init__(parent)

    def run(self):
        randomSample = random.sample(range(0, 10), 10)

        self.newSample.emit(randomSample)

class MyWindow(QtGui.QWidget):
    def __init__(self, parent=None):
        super(MyWindow, self).__init__(parent)

        self.pushButtonPlot = QtGui.QPushButton(self)
        self.pushButtonPlot.setText("Plot")
        self.pushButtonPlot.clicked.connect(self.on_pushButtonPlot_clicked)

        self.matplotlibWidget = MatplotlibWidget(self)

        self.layoutVertical = QtGui.QVBoxLayout(self)
        self.layoutVertical.addWidget(self.pushButtonPlot)
        self.layoutVertical.addWidget(self.matplotlibWidget)

        self.threadSample = ThreadSample(self)
        self.threadSample.newSample.connect(self.on_threadSample_newSample)
        self.threadSample.finished.connect(self.on_threadSample_finished)

    @QtCore.pyqtSlot()
    def on_pushButtonPlot_clicked(self):
        self.samples = 0
        self.matplotlibWidget.axis.clear()
        self.threadSample.start()

    @QtCore.pyqtSlot(list)
    def on_threadSample_newSample(self, sample):
        self.matplotlibWidget.axis.plot(sample)
        self.matplotlibWidget.canvas.draw()

    @QtCore.pyqtSlot()
    def on_threadSample_finished(self):
        self.samples += 1
        if self.samples <= 2:
            self.threadSample.start()

if __name__ == "__main__":
    import sys

    app = QtGui.QApplication(sys.argv)
    app.setApplicationName('MyWindow')

    main = MyWindow()
    main.resize(666, 333)
    main.show()

    sys.exit(app.exec_())