I expanded the embedding_in_qt4.py with a blitting canvas.

If you want to use it in the example section or anything else, you are welcome.

greetings
Till

#!/usr/bin/env python

# embedding_in_qt4.py --- Simple Qt4 application embedding matplotlib canvases
# It also shows, that normal plotting is quite slow.

···

#
# 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.

import sys, os, random
from PyQt4 import QtGui, QtCore

from numpy import arange, sin, pi
from numpy.random import randn, randint
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)
        self.timer = QtCore.QTimer(self)
        QtCore.QObject.connect(self.timer, QtCore.SIGNAL("timeout()"), self.update_figure)
        self.timer.start(1000)

    def compute_initial_figure(self):
         self.axes.plot(arange(4), randint(0, 10, 4), 'r')

    def update_figure(self):
        # Build a list of 4 random integers between 0 and 10 (both inclusive)
        l = randint(0, 10, 4)
        self.axes.plot(arange(1, 5), l, 'r')
        self.draw()
        def stop_timer(self):
        self.timer.stop()
        
    class MyBlittMplCanvas(MyMplCanvas):
    """"A canvas thats updates itself as fast a possible, using blitting."""
    def __init__(self, *args, **kwargs):
        MyMplCanvas.__init__(self, *args, **kwargs)
                    #self.draw()

        self.old_size = self.axes.bbox.width, self.axes.bbox.height
        self.ax_background = self.copy_from_bbox(self.axes.bbox)
        self.cnt = 0
        self.axes.set_autoscale_on(False)
        #self.draw() self.timer=QtCore.QTimer()
        self.connect(self.timer, QtCore.SIGNAL("timeout()"), self.update_figure)
        self.timer.start(0)
        def blit(self, bbox=None):
        self.replot = bbox
        l, b, w, h = bbox.bounds
        t = b + h
        self.repaint(l, self.renderer.height-t, w, h)
        def compute_initial_figure(self): self.t = arange(0.0, 3.0, 0.01)
        s = sin(2*pi*self.t)+randn(len(self.t))
        self.line=self.axes.plot(self.t, s)[0]
        def update_figure(self): current_size = self.axes.bbox.width, self.axes.bbox.height
        if self.old_size != current_size:
            self.old_size = current_size
            self.axes.clear()
            self.axes.grid()
            self.draw()
            self.ax_background = self.copy_from_bbox(self.axes.bbox)

        self.restore_region(self.ax_background, bbox=self.axes.bbox)

        # update the data
        self.line.set_ydata(sin(2*pi*self.t)+randn(len(self.t)))
                # just draw the animated artist
        self.axes.draw_artist(self.line)
        # just redraw the axes rectangle
        self.blit(self.axes.bbox)
     
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)
        bc = MyBlittMplCanvas(self.main_widget, width=5, height=4, dpi=100)
        stopdc=QtGui.QPushButton("Stop dynamic Timer")
        self.connect(stopdc, QtCore.SIGNAL("clicked()"), dc.stop_timer)
        l.addWidget(sc)
        l.addWidget(dc)
        l.addWidget(stopdc)
        l.addWidget(bc)
        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 %s" % progname,
u"""%(prog)s version %(version)s
Copyright \N{COPYRIGHT SIGN} 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."""
% {"prog": progname, "version": progversion})

qApp = QtGui.QApplication(sys.argv)

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

We also have an existing blitting example at
http://matplotlib.sourceforge.net/examples/animation/animation_blit_qt4.html
. I would prefer not to add blitting to the emedding_in_qt4 example,
so we can keep it as short and simple as possible.

Darren

···

On Sat, Dec 26, 2009 at 12:52 PM, Till Stensitzki <mail.till@...380...> wrote:

If you want to use it in the example section or anything else, you are
welcome.