Question

I have a scatter graph and have implemented a highlighter type thing through matplotlib http://matplotlib.org/users/transforms_tutorial.html#axes-coordinates.

At the moment, when you click any of the points the highlighter appears at the same place, but what i want to do, is when you click a certain point, it takes the coordinates from the point and highlights where the point is.
my code is this

def onclick    
    ind = event.ind
    # the x coords of this transformation are data, and the
    # y coord are axes
    trans = transforms.blended_transform_factory(
    ax.transData, ax.transAxes)

    # highlight the 1..2 stddev region with a span.
    # We want x to be in data coordinates and y to
    # span from 0..1 in axes coords
    rect = patches.Rectangle((1,0), width=1, height=1,
                     transform=trans, color='yellow',
                     alpha=0.5)

    ax.add_patch(rect)
    print ('on pick scatter:' , ind , np.take(x,ind), np.take(y,ind))

Answer 1

There is probably a shorter way to do this but this is my crack at it and it works 🙂

    def onpick3(event):
            ind = event.ind
    l = np.take(x,ind)
        for i in range(0,1):
                d = l[i]



    if highlight == 1 :

        global highlight
        highlight = 0;
        self.canvas.draw()
            if highlight == 0 :

            trans = transforms.blended_transform_factory(self.axes.transData, self.axes.transAxes)
                rect = patches.Rectangle(((d-10),0),width=25, height=25, transform=trans, color='yellow',alpha=0.5)
                self.axes.add_patch(rect)
            self.canvas.draw()
        rect.remove()
        else:
         self.canvas.draw()
         trans = transforms.blended_transform_factory(self.axes.transData, self.axes.transAxes)
             rect = patches.Rectangle(((d-10),0),width=25, height=25, transform=trans, color='yellow',alpha=0.5)
             self.axes.add_patch(rect)
         self.canvas.draw()
         highlight = 1
         rect.remove()
            print ('onpick3 scatter:', ind, np.take(x, ind), np.take(y, ind))