Sum With Axis

07 May 2019

import numpy as np

a = np.array([
    [1, 2],
    [3, 4]
])

# Sum
a.sum()

# 
a.sum(axis=0)

array([4, 6])

b = np.array([
    [10, 20, 30, 40],
    [100, 200, 300, 400]
])

array([[ 10,  20,  30,  40],
       [100, 200, 300, 400]])

b.ndim

b.sum(axis=0)

array([110, 220, 330, 440])

b.sum(axis=1)

array([ 100, 1000])

More explained here: