Elementwise logical comparison of numpy arrays

Question

I have two numpy arrays of the same shape. The elements in the arrays are random integers from [0,N]. I need to check which (if any) of the elements in the same position in the arrays are equal.

The output I need are the positions of the same elements.

mock code:

A=np.array([0,1])
B=np.array([1,0])
C=np.array([1,1])
np.any_elemenwise(A,B)
np.any_elemenwise(A,C)
np.any_elemenwise(A,A)

desired output:

[]
[1]
[0,1]

I can write a loop going through all of the elements one by one, but I assume that the desired output can be achieved much faster.

score 6 · Accepted Answer · answered Mar 24 '14 at 09:50

6

EDIT:The question changed.

You just want to evaluate np.where(v1==v2)[0]

answered Mar 24 '14 at 09:50

gg349

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I edited the question to make it clearer and decided to drop the truth-value because I was thinking that I can always check len(output)==0. – Artturi Björk Mar 24 '14 at 09:54
no problem, I think the updated question shows a better design anyway. – gg349 Mar 24 '14 at 09:55

Elementwise logical comparison of numpy arrays

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