Division of two plt.hist2d

Question

I have two 2D-histograms, one containing a total number of shots and the other containing the total number of shots succeeded. I would like to divide these two histograms in order to have one with the success rate of shots per zone.

This is the initial data frame :

This is my first 2D-histogram with the total number of shots :

This is my second 2D-histogram with the total number of shots succeeded :

This is my code for both histograms :

fig = plt.figure() #set up the figures
fig.set_size_inches(10, 7)
ax = fig.add_subplot(1,1,1)
draw_pitch_horizontal(ax) #overlay our different objects on the pitch
colors = {'Goal Kicked':'tab:blue','Goal Missed':'tab:red'}
penalty = plt.hist2d(kick.nouveau_x,kick.nouveau_y, bins=[np.arange(0,130,10),np.arange(0,90,10)],cmap=plt.cm.Reds) 
plt.ylim(-2, 82)
plt.xlim(-2, 122)
plt.colorbar()
plt.title('Map des pénalités',fontsize=16)
plt.axis('off')
plt.show()

fig.set_size_inches(10,7)
ax = fig.add_subplot(1,1,1)
draw_pitch_horizontal(ax) #overlay our different objects on the pitch
colors = {'Goal Kicked':'tab:blue','Goal Missed':'tab:red'}
kicked = plt.hist2d(kick[kick.outcome == 'Goal Kicked'].nouveau_x,kick[kick.outcome == 'Goal Kicked'].nouveau_y, bins=[np.arange(0,130,10),np.arange(0,90,10)],cmap=plt.cm.Reds)
plt.ylim(-2, 82)
plt.xlim(-2, 122)
plt.colorbar()
plt.title('Map des pénalités réussies',fontsize=16)
plt.axis('off')
plt.show() 

I tried to divide my variables penalty and kicked but then I have a list of arrays and I don't know how to plot it on my pitch.

Answer 1

The hist2d function returns 4 things: the 2-D array of data (you want this), the bin edges in each direction (which you already have), and the quadmesh object (which you don't really need). You can use the 2-D arrays to compute what you want.

Replace the penalty = ... line in the first blocks with:

bins=[np.arange(0,130,10), np.arange(0,90,10)]
success = kick.outcome == 'Goal Kicked'

h_penalty, xedges, yedges, image = plt.hist2d(kick.nouveau_x,
                                              kick.nouveau_y,
                                              bins=bins,
                                              cmap=plt.cm.Reds,
                                              ) 

And replace the kicked = ... line in the second block with:

h_kicked, xedges, yedges, image = plt.hist2d(kick[success].nouveau_x,
                                             kick[success].nouveau_y,
                                             bins=bins,
                                             cmap=plt.cm.Reds,
                                             )

Then you can do:

success_rate = 100 * h_kicked / h_penalty

And you can show that with something like im = plt.imshow(success_rate), or another quadmesh.