lab's version of kmeans does not have outliers.

 USAGE
  [ IDX, C, d ] = kmeans2( X, k, [varargin] )

 INPUTS
  X       - [n x p] matrix of n p-dim vectors.
  k       - maximum nuber of clusters (actual number may be smaller)
  prm     - additional params (struct or name/value pairs)
   .k         - [] alternate way of specifying k (if not given above)
   .nTrial    - [1] number random restarts
   .maxIter   - [100] max number of iterations
   .display   - [0] Whether or not to display algorithm status
   