MATLAB: Selecting different element of a matrix with each function operation

Question

Hi guys,

Say I have a two column 5×2 matrix A (defined as a global variable) with 0,1,2,3,4 in the first column and 2,4,6,8,10 in the second column. Say I also have a function in a separate function file that goes something like this:

function y = func(x)
global A;
y = x - A(p,n)
end

In my main Matlab file (where A is), I've set up a 'while' loop whereby func(x) continuously operates for a total of 5 times.

So my question/problem is this: for each operation of func(x), is it possible to select a different element of the matrix A. For example, for the first func(x) operation, I want it to carry out y = x – A(1,2); for the second func(x) operation, I want it to carry out y = x – A(2,2), and so on until the fifth func(x) operation completes.

Hopefully this is somewhat understandable – I've 'created' the above problem as an example designed to highlight the specific issue I'm trying to tackle, so it might not work/make sense as a whole.

Any help is greatly appreciated.

Answer 1

Hi JD,

You could pass a counter variable i to your function as such:

i = 1;
while condition
  i = i+1;
end
function y = func(x, i)
  global A;
  y = x - A(i,2);
end