Python编程，计算class频率

Question

k=np.array(
    [[1, 0, 0],
     [0, 1, 1],
     [1, 0, 1],
     [1, 1, 1],
     [1, 0, 1]]
)

In this array, how can I compute the frequency of each column For example: If I need positive case, the output should be [4,2,4] If I need negative case, the output should be [2,3,1]

Answer 1

If it's just these two numeric symbols (meaning you can treat them as numbers).

import numpy as np
k=np.array(
    [[1, 0, 0],
     [0, 1, 1],
     [1, 0, 1],
     [1, 1, 1],
     [1, 0, 1]]
)
print(np.sum(k,axis=0))
print(np.sum(1-k,axis=0))

output:

[4 2 4]

[1 3 1]