[Matplotlib-users] Some help with PyQt

[Eric F. <eri...@gm...>]

I took the example that ships with 1.3.0 and have modified it to use a grid
layout and show 9 graphs in a 3x3 grid.
When I do this it, other widgets become rather unresponsive.
Is there a way to fix this?
Somehow offload whatever is hogging CPU onto another thread or something?

Below is the code....

Thanks,
~Eric


#!/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, os, random
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 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)
        QtCore.QObject.connect(timer, QtCore.SIGNAL("timeout()"),
self.update_figure)
        timer.start(750)

    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("Unresponsive Application")

        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)

        main_layout = QtGui.QVBoxLayout()
        chart_layout = QtGui.QGridLayout()
        for row in range(3):
            for col in range(3):
                dc = MyDynamicMplCanvas(self.main_widget, width=5,
height=4, dpi=100)
                chart_layout.addWidget(dc, row, col)


        main_layout.addWidget(QtGui.QPushButton("Unresponsive"))
        main_layout.addWidget(QtGui.QPushButton("Widgets"))

        horizontalSlider = QtGui.QSlider()
        horizontalSlider.setOrientation(QtCore.Qt.Horizontal)
        main_layout.addWidget(horizontalSlider)

        main_layout.addLayout(chart_layout)



        self.main_widget.setLayout(main_layout)
        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."""
)

if __name__ == '__main__':
    app = QtGui.QApplication(sys.argv)
    aw = ApplicationWindow()
    aw.show()
    sys.exit(app.exec_())