.. _old_animation-animate_decay_tk_blit:

old_animation example code: animate_decay_tk_blit.py
====================================================

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

::

    import time, sys
    import numpy as np
    import matplotlib.pyplot as plt
    
    
    def data_gen():
        t = data_gen.t
        data_gen.t += 0.05
        return np.sin(2*np.pi*t) * np.exp(-t/10.)
    data_gen.t = 0
    
    fig = plt.figure()
    ax = fig.add_subplot(111)
    line, = ax.plot([], [], animated=True, lw=2)
    ax.set_ylim(-1.1, 1.1)
    ax.set_xlim(0, 5)
    ax.grid()
    xdata, ydata = [], []
    def run(*args):
        background = fig.canvas.copy_from_bbox(ax.bbox)
        # for profiling
        tstart = time.time()
    
        while 1:
            # restore the clean slate background
            fig.canvas.restore_region(background)
            # update the data
            t = data_gen.t
            y = data_gen()
            xdata.append(t)
            ydata.append(y)
            xmin, xmax = ax.get_xlim()
            if t>=xmax:
                ax.set_xlim(xmin, 2*xmax)
                fig.canvas.draw()
                background = fig.canvas.copy_from_bbox(ax.bbox)
    
            line.set_data(xdata, ydata)
    
            # just draw the animated artist
            ax.draw_artist(line)
            # just redraw the axes rectangle
            fig.canvas.blit(ax.bbox)
    
            if run.cnt==1000:
                # print the timing info and quit
                print 'FPS:' , 1000/(time.time()-tstart)
                sys.exit()
    
            run.cnt += 1
    run.cnt = 0
    
    
    
    manager = plt.get_current_fig_manager()
    manager.window.after(100, run)
    
    plt.show()
    

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