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?

score 10 · Accepted Answer · answered Aug 12 '11 at 10:51

10

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])

answered Aug 12 '11 at 10:51

eumiro

5

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. – dtlussier Aug 15 '11 at 17:36

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