What does this mean?

Question

0

936

3

+66

This: ∑_iX_ij²

chaconsara32 Apr 28, 2018

+33652

+5

Best Answer

I suspect this means something like:

X is a matrix with, say, N rows and M columns. Subscript i runs from 1 to N; subscript j runs from 1 to M.

\(\Sigma_iX_{ij}^2\) returns the sum of the squares of all elements from row 1 to row N in column j.

Alan Apr 28, 2018

edited by Alan Apr 28, 2018

Alan · Answer 1 · 2018-04-28T06:47:54

I suspect this means something like:

X is a matrix with, say, N rows and M columns. Subscript i runs from 1 to N; subscript j runs from 1 to M.

\(\Sigma_iX_{ij}^2\) returns the sum of the squares of all elements from row 1 to row N in column j.

Melody · Answer 2 · 2018-04-28T05:54:38

Well that is a part of a bigger question but it looks like it could a part of a matrix question.

It doesn't make sense on its own.

chaconsara32 · Answer 3 · 2018-05-01T07:30:40

Thanks! :)