def zoomplots(event=None, ratio=1.0):
    ''' Zoom in or out '''
    global plotfig
    for ax in plotfig.axes:
        axpos = ax.get_position()
        x0 = axpos.x0
        x1 = axpos.x1
        y0 = axpos.y0
        y1 = axpos.y1
        xdiff = x1-x0
        ydiff = y1-y0
        xchange = xdiff*(1-ratio)/2.0
        ychange = ydiff*(1-ratio)/2.0
        ax.set_position([x0+xchange, y0+ychange, xdiff*ratio, ydiff*ratio])
    return None