CODEWITHSUNDEEP
pythonmatplotlibseaborn
MrPedru22
MrPedru22

Reputation: 1344

Highlight cell in seaborn heatmap through mouse hover

I am trying to associate a motion event to a seaborn heatmap, so that when I hover the mouse in a cell, this cell gets highlighted in the borders. So far, I managed to do it, by associating a motion_notify_event to the canvas:

import matplotlib.patches as mpatches

self.canvash.mpl_connect('motion_notify_event', self.onMotion)

(...)

def onMotion(self,event):
    if not event.inaxes: 
        return 

    xint = int(event.xdata)
    yint = int(event.ydata)

    self.axh.add_patch(mpatches.Rectangle((xint, yint),1,1,fill=False,edgecolor='blue',linewidth=0.5))

    self.canvash.draw()

This works, and as I hover the mouse, the cells get highlighted. The problem is that all the cells will get highlighted, and the result is something like this:

enter image description here

I just want to highlight the cell under the mouse as I move it, so that only one is active.

How can I do this?

Upvotes: 0

Views: 1649

Answers (1)

MrPedru22
MrPedru22

Reputation: 1344

I was able to find a solution, thanks to Paul H. I just had to save the patch and then remove it and it works fine, here is the solution:

def onMotion(self,event):

    if not event.inaxes: 
        return

    xint = int(event.xdata)
    yint = int(event.ydata)

    self.rect = mpatches.Rectangle((xint, yint),1,1,fill=False,linestyle='dashed', edgecolor='red',linewidth=2.0)

    self.axh.add_patch(self.rect)

    self.canvash.draw()   

    self.rect.remove()

Upvotes: 1

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