MATLAB: Replicating values a certain number of times

Question

Hello, I have a long array of data from 0 to 1959 in steps of 1. Is there any way to expand that data so that each value repeats x number of times? ie. if x is 4

new = 0 0 0 0 1 1 1 1 2 2 2 2 3 3 3 3…

I have compressed data and I want to be able to expand it with this approximation.

Thanks for your help!

Answer 1

There are a number of ways to do this.

One way use a constant interpolator:

 x = 0:9;
 h = ones(4,1);
 xnew = zeros(40,1);
 xnew(1:4:end) = x;
 y = filter(h,1,xnew);

Another way use repmat()

 x = (0:9)';
 x = (repmat(x,1,4))';
 x = reshape(x,40,1);