MATLAB: Create matrix with step of columns

MATLABmatrix manipulation

clear; clc;
 
v = 1:257;
n = 10;
k = 7;
 
newV = (repmat(v, n, 1) + k) .* 2.^(0:(n-1))' - k;

Now I have a matrix with first column, for example if k=7, I have [1;9;25;57;121], but I need column [1;9;17;25;33;41].

How to do this?

newV = (0:n-1).'*k + v;

Try

 k = [k_fil k_omv]

alternatively, you could use

 k = horzcat(k_fil, k_omv)

assuming that you do want to concatenate the arrays.

As the doc states, PARFOR needs to work with unit-step ranges. So you do need to re-work the loop slightly, something like this:

   idx = 1:10:75;
   parfor (i = 1:numel(idx), 8)
     val = idx(i);
     test3t(i) = val * 3;
   end

That example leaves 'test3t' slightly different to 'test3' in your example, you can rearrange things by doing

test3(idx) = test3t;