Subsetting numpy arrays

Question

I want to subset a d = (d1,...,dn)-shaped numpy array A to get only the r = (r1,...,rn) first principal minor, i.e all values A[i1,...,in] such that ij < rj. The resulting array has shape r, of course.

How can i do that ? I tried A[:r] but of course it did not work :). The right way would be A[:r1,...,:rn], but len(A.shape) is unknown, so i cant write all subsetting one by one.

Do you have an idea on how i could get this submatrix ?

Nils Werner · Accepted Answer · 2020-11-03 11:46:31Z

2

You can use

A[tuple([slice(None, i) for i in r])]

answered Nov 3, 2020 at 11:46

Nils Werner

37.2k7 gold badges85 silver badges108 bronze badges

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

2 Comments

lrnv Over a year ago

Perfec, thanks. Did not know about the slice() function !

John Zwinck Over a year ago

The inner pair of square brackets are unnecessary, but otherwise looks good.

Collectives™ on Stack Overflow

Subsetting numpy arrays

1 Answer 1

2 Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

2 Comments

Your Answer

Sign up or log in

Post as a guest

Related