The argsort()
function returns a matrix of indices that can be used to index the original array so that the result would match the sort()
result.
Is there a way to apply those indices? I have two arrays, one is the array used for obtaining the sort order, and another is some associated data.
I would like to compute assoc_data[array1.argsort()]
but that doesn't seem to work.
Here's an example:
z=array([1,2,3,4,5,6,7])
z2=array([z,z*z-7])
i=z2.argsort()
z2=array([[ 1, 2, 3, 4, 5, 6, 7],[-6, -3, 2, 9, 18, 29, 42]])
i =array([[1, 1, 1, 0, 0, 0, 0],[0, 0, 0, 1, 1, 1, 1]])
I would like to apply i to z2 (or another array with associated data) but I'm not sure how to do so.