Show coordinates under cursor for iris

geo_debug_plot.py

...
iplt.pcolormesh(cube)

# https://matplotlib.org/gallery/api/image_zcoord.html                         
numrows, numcols = cube.shape                                                  
def format_coord(x, y):                                                        
    #col = int(x + 0.5)                                                        
    #row = int(y + 0.5)                                                        
    row = int(abs(cube.coord(axis='y').points - y).argmin())                   
    col = int(abs(cube.coord(axis='x').points - x).argmin())                   
    if col >= 0 and col < numcols and row >= 0 and row < numrows:              
        z = cube.data[row, col]                                                
        return 'x=%1.4f, y=%1.4f, z=%1.4f (row:%i, col:%i)' % (x, y, z, row, col)
    else:                                                                      
        return 'x=%1.4f, y=%1.4f' % (x, y)                                     
                                                                               
iplt.plt.gca().format_coord = format_coord                                     
                                                                               
iplt.show()