which point corresponds to which cluster in kemans function

hi to all.. i am using kmeans function for clustering.In that i am obtaining centroid locations. but i need which point corresponds to which cluster.because i need to fix the k value for the clustering.For that i need to calculate distance between each point and its corresponding cluster centroid......can anyone help me to find points corresponds to each cluster.

Answer 1

[Tom Lane]

If you are using kmeans from the Statistics Toolbox, it sounds like the first output is what you want:

>> [a,b] = kmeans([0 0;0 .01; 1 1],2)
a =
     2
     2
     1
b =
    1.0000    1.0000
         0    0.0050

This shows that the first two points correspond to cluster 2, with a centroid [0 .005], and the other point corresponds to cluster 1.

If you want to compute the distance between new points and the centroids, the pdist2 function might be useful.