I believe your goal can be more easily solved using the built in Matlab function reshape. It looks to me like you have a 1x300000 vector that you would like to turn into a 1000x300 array. reshape function can do that like this :
store = reshape(RLF,[1000,300]);
If you wish to be sure that this is working the way you want it to, you can test it by making RLF 1:300000 first.
If instead, you want to continue doing it with a loop the following code should work fine
store = zeros(1000,300);
for n = 1:300
store(:,n)=RLF(1+(n-1)*1000 : n*1000);
end
The indexing there causes the indexes to go from 1:1000, 1001:2000, 2001:3000 and so on.
Hope this helps
