numpy.argmax: how to get the index corresponding to the *last* occurrence, in case of multiple occurrences of the maximum values

Question

I have an array of numbers, and the maximum value might occurrence more than once.

Is it possible to find the index of the last occurrence of the maximum value by using something like numpy.argmax?

Or, even better, is it possible to get a list of indices of all the occurrences of the maximum value in the array?

Solution

import numpy as np

a = np.array((1,2,3,2,3,2,1,3))

occurences = np.where(a == a.max())

# occurences == array([2, 4, 7])

Comments

[dtlussier]

I'm not sure if this is true with more recent versions, but with v1.4.0, should have occurences = np.where(a == a.max())[0] such that you get an array rather than a tuple in occurences.