MATLAB: How to fill a preallocated matrix with function output

Question

Hi there.

I've preallocated a zeros(10,4) matrix. I'm trying to store the result or "fill" each row with the output of another function (that I didn't write). The output of the function is a 1×4 array (i.e. [1 2 3 4]). I effectively want to replace each row with "ans" but I know that's just not cool.

I assume this is done by concatenation… However, the best I can do is add to the array… but there's still the 10×4 zeros below it. Is there a way to do it with indices/for loop? I'm up for whatever's easiest.

example:

A = zeros(10,4) and my 1×4 output = [1 2 3 4]

How would I replace A's first row with [1 2 3 4] without just "adding" to it?

Thanks!

Answer 1

 A(r,:) = [1 2 3 4];

or

 A(r,:) = 1x4 output of function

These place the 1x4 array in the r-th row.