stevenvo/numpy-array-sort.py

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Sort array by nth column in Numpy

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numpy-array-sort.py

	# sort array with regards to nth column
	arr = arr[arr[:,n].argsort()]

sywyyhykkk commented Sep 2, 2018

Thanks!

malikasri94 commented Oct 23, 2018

Could you tell me the code if I want the decreasing order?
For example:
mat = np.array([[1,21,3],[5,4,2],[56,12,4]])
mat_sort = mat[mat[:,2].argsort()]
print(mat_sort)

Output:
[[ 5 4 2]
[ 1 21 3]
[56 12 4]]

But if I want sorting based on 3rd column in decreasing order?

philippemiron commented Oct 27, 2018

You could reverse the .argsort() results:

mat_sort = mat[mat[:,2].argsort()[::-1]]

dmitrymoshkin commented Apr 23, 2019

Cool, thanx

ajoyvmw commented Jun 16, 2019

Very nice!

nalin-mathur-oyo commented Aug 8, 2019

This is not working when I am trying it out. Posting a code snippet to show the results I am getting. Please suggest as to what I should do.

Currently using python 3.7.4.

dzy0023 commented Dec 3, 2019

This is not working when I am trying it out. Posting a code snippet to show the results I am getting. Please suggest as to what I should do.

Currently using python 3.7.4.

its a func for ndarray

Lelik92 commented Nov 16, 2020

Could I sort all matrix columns in descending order in similar way by using argsort()?

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