'This add the coordinates of an event to the list of clicks'

def add_click(self, event):

    self.clicks.append((event.xdata, event.ydata))
    verbose.report((u'input    %i:    %f,%f' % (len(self.clicks), event.xdata, event.ydata)))
    if self.show_clicks:
        line = mlines.Line2D([event.xdata], [event.ydata], marker=u'+', color=u'r')
        event.inaxes.add_line(line)
        self.marks.append(line)
        self.fig.canvas.draw()
