MATLAB: Down-sampling with interp1

down-samplinginterpolation

Hi,
I have a vector with 1500 rows, and I am trying to down-sample this using interp1 like this:
downsampled = interp1([1:length(original)],original,1:1:100);
However, it looks like the output "downsampled' is just a copy of the first 100 rows of original. Any hints on this?
Cheers

oL = length(original);downsampled = interp1(1:oL, original, linspace(1,oL,100));