How to sort first row in numpy array and have that sort the second row?

Question

I have an array that looks like this:

array = numpy.array([[3,5,4,2,1,6,8],[23,44,52,1,23,22,58]])

How do I sort the first row and have it change the result of the second row as well? This is what I mean:

new_array = [[1,2,3,4,5,6,8],[23,1,23,52,44,22,58]]

Does this answer your question? How to sort a numpy array based on the values in a specific row? — Corralien
– Corralien, Commented Sep 16, 2021 at 22:37

akuiper · Accepted Answer · 2021-09-16 22:36:19Z

1

You can use argsort, array[0].argsort() gives the indices that will sort the first row and then use the indices to reorder all columns:

array[:, array[0].argsort()]
array([[ 1,  2,  3,  4,  5,  6,  8],
       [23,  1, 23, 52, 44, 22, 58]])

answered Sep 16, 2021 at 22:36

akuiper

216k33 gold badges362 silver badges379 bronze badges

Sign up to request clarification or add additional context in comments.

1 Answer 1