.. _old_animation-animation_blit_qt:

old_animation example code: animation_blit_qt.py
================================================

[`source code <animation_blit_qt.py>`_]

::

    # For detailed comments on animation and the techniqes used here, see
    # the wiki entry http://www.scipy.org/Cookbook/Matplotlib/Animations
    
    from __future__ import print_function
    
    import os, sys
    import matplotlib
    matplotlib.use('QtAgg') # qt3 example
    
    from qt import *
    # Note: color-intensive applications may require a different color allocation
    # strategy.
    QApplication.setColorSpec(QApplication.NormalColor)
    
    TRUE  = 1
    FALSE = 0
    ITERS = 1000
    
    import pylab as p
    import numpy as npy
    import time
    
    class BlitQT(QObject):
        def __init__(self):
            QObject.__init__(self, None, "app")
    
            self.ax = p.subplot(111)
            self.canvas = self.ax.figure.canvas
            self.cnt = 0
    
            # create the initial line
            self.x = npy.arange(0,2*npy.pi,0.01)
            self.line, = p.plot(self.x, npy.sin(self.x), animated=True, lw=2)
    
            self.background = None
    
        def timerEvent(self, evt):
            if self.background is None:
                self.background = self.canvas.copy_from_bbox(self.ax.bbox)
    
            # restore the clean slate background
            self.canvas.restore_region(self.background)
            # update the data
            self.line.set_ydata(npy.sin(self.x+self.cnt/10.0))
            # just draw the animated artist
            self.ax.draw_artist(self.line)
            # just redraw the axes rectangle
            self.canvas.blit(self.ax.bbox)
    
            if self.cnt==ITERS:
                # print the timing info and quit
                print('FPS:', ITERS/(time.time()-self.tstart))
                sys.exit()
    
            else:
                self.cnt += 1
    
    p.subplots_adjust(left=0.3, bottom=0.3) # check for flipy bugs
    p.grid() # to ensure proper background restore
    
    app = BlitQT()
    # for profiling
    app.tstart = time.time()
    app.startTimer(0)
    
    p.show()
    

Keywords: python, matplotlib, pylab, example, codex (see :ref:`how-to-search-examples`)