How to get the index of a maximum element in a NumPy array along one axis

Question

I have a 2 dimensional NumPy array. I know how to get the maximum values over axes:

>>> a = array([[1,2,3],[4,3,1]]) >>> amax(a,axis=0) array([4, 3, 3]) 

How can I get the indices of the maximum elements? I would like as output array([1,1,0]) instead.

Answer 1

>>> a.argmax(axis=0)  array([1, 1, 0]) 

Answer 2

>>> import numpy as np >>> a = np.array([[1,2,3],[4,3,1]]) >>> i,j = np.unravel_index(a.argmax(), a.shape) >>> a[i,j] 4