I am not certain that I understand what you want to do. You are apparently using only 14 of the 16 elements (or rows or columns) in your data set. If that is true, you can calculate the indices as:
idx = ceil(rem(nf,7.1));
This will ‘reset’ them to repeat the 1:7 series as long as you want.
You can test that with:
nf = 1:14
idx = ceil(rem(nf,7.1))
to see the result.
