Numpy sort two arrays together with one array as the keys in axis 1

Asked Aug 01 '19 at 20:22

Active Aug 01 '19 at 20:51

Viewed 48 times

I have two array

scores = np.array([[0.3, 0.5, 0.1], [0.2, 0.2, 0.1], [0.1, 0.2, 0.3]])
ids = np.array([[1,2,3],[4,5,6],[7,8,9]])

what I want is to sort two array together in the column dimension with the scores array as the sorting keys.

I tried

sort_idxes = np.argsort(scores)
scores = scores[sort_idxes]
ids = ids[sort_idxes]

which gives two 3x3x3 arrays. What I want is just sorted scores and ids as the following

 scores: [
[0.1, 0.3, 0.5], 
[0.1, 0.2, 0.2],
[0.1, 0.2, 0.3]]

 ids: [
[3, 1, 2], 
[6, 4, 5], 
[7, 8, 9]]

edited Aug 01 '19 at 20:51

asked Aug 01 '19 at 20:22

Tony

1

Use `scores[np.arange(scores.shape[0])[:, None], sort_idxes]` – user3483203 Aug 01 '19 at 20:50
1

Don't use the below answer, it's not vectorized and will be quite slow on large inputs. Use `numpy` methods for numpy problems. – user3483203 Aug 01 '19 at 23:02

0 Answers0