.. _event_handling-zoom_window:

event_handling example code: zoom_window.py
===========================================

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

::

    """
    This example shows how to connect events in one window, for example, a mouse
    press, to another figure window.
    
    If you click on a point in the first window, the z and y limits of the
    second will be adjusted so that the center of the zoom in the second
    window will be the x,y coordinates of the clicked point.
    
    Note the diameter of the circles in the scatter are defined in
    points**2, so their size is independent of the zoom
    """
    from matplotlib.pyplot import figure, show
    import numpy
    figsrc = figure()
    figzoom = figure()
    
    axsrc = figsrc.add_subplot(111, xlim=(0, 1), ylim=(0, 1), autoscale_on=False)
    axzoom = figzoom.add_subplot(111, xlim=(0.45, 0.55), ylim=(0.4, .6),
                                 autoscale_on=False)
    axsrc.set_title('Click to zoom')
    axzoom.set_title('zoom window')
    x, y, s, c = numpy.random.rand(4, 200)
    s *= 200
    
    
    axsrc.scatter(x, y, s, c)
    axzoom.scatter(x, y, s, c)
    
    
    def onpress(event):
        if event.button != 1:
            return
        x, y = event.xdata, event.ydata
        axzoom.set_xlim(x - 0.1, x + 0.1)
        axzoom.set_ylim(y - 0.1, y + 0.1)
        figzoom.canvas.draw()
    
    figsrc.canvas.mpl_connect('button_press_event', onpress)
    show()
    

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