from numba import jit

@jit
def variant(array,delta):
    var=np.zeros_like(array)
    for i in range(500):
        for j in range(500):
            for k in range(188):
                var[k,j,i]=abs(array[k,j,i]-np.nanmean(array[k,j-delta:j+delta,i-delta:i+delta]))

    return(var)