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i can't still figure out how to do this the best possible way with less code, i have a Ndarray called X : array([0.5 , 2 , 3.2 , 0.16 , 3.3 , 10 , 12 , 2.5 , 10 , 1.2 ]) and i want somehow to get the smallest 5 values with their position in X as in i want ( 0.5 , 0.16 , 1.2, 2 ,2.5 ) and to know that they are the first and fourth and 10th and second 8th in the ndarray X ( the are actually the the values of a row in a matrix and i want to know the position of the smallest 5 ) thank you!

NexNex
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  • Does this answer your question? [Find the index of the k smallest values of a numpy array](https://stackoverflow.com/questions/34226400/find-the-index-of-the-k-smallest-values-of-a-numpy-array) – AMC Jan 16 '20 at 20:58

1 Answers1

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You can use ndarray.argpartition:

X = np.array([0.5 , 2 , 3.2 , 0.16 , 3.3 , 10 , 12 , 2.5 , 10 , 1.2 ])

n = 5
arg = X.argpartition(range(n))[:n]

print(arg)
# [3 0 9 1 7]

print(X[arg])
# [0.16 0.5  1.2  2.   2.5 ]
yatu
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