将多维 numpy 数组中的列提高到 2 次方

Question

I have no idea how to raise a column to the 2nd power, I've done some googling and nothing came up. I've tried: X[:,-1:0] = X[:,-1:0] ** 2 , when X is a 47*3 numpy matrix, and I want to raise the last column to the 2nd power and it didn't work.

Answer 1

Unless I've misunderstood your problem, a simple for loop should suffice

from numpy import array
a = array([[1, 3, 5], [2, 3, 6], [4, 3, 9]])
for r in a:
    r[-1] = r[-1]**2
print(a)