Date: Sep 22, 2012 4:27 PM Author: email@example.com Subject: Binary or Logical Selection : Given an array A and a binary or<br> logical vector S, how do I select the rows of A when S = 1 or True ? Given a 3 column array A of x,y,z numbers, defining a set of spatial coordinates, and a binary or logical selection vector S (with as many elements as rows in A) :
How do I express the operation of selecting an array R with the set of those co-ordinates in A where S is 1 (or true) ?
In Apl I write this as R ? S / A .
But a referee of a paper is asking that I express this in standard maths, and I have not yet managed to find an appropriate mathematical expression.
Cheers for any help,