[R] using SVD to get an inverse matrix of covariance matrix

2003-07-11 Thread ge yreyt
Dear R-users, I have one question about using SVD to get an inverse matrix of covariance matrix Sometimes I met many singular values d are close to 0: look this example $d [1] 4.178853e+00 2.722005e+00 2.139863e+00 1.867628e+00 1.588967e+00 [6] 1.401554e+00 1.256964e+00 1.185750e+00 1.060692e+

[R] estimate the number of clusters

2003-06-09 Thread ge yreyt
Dear All, I am using Silhouette to estimate the number of clusters in a microarray dataset. Initially, I used the iris data to test my piece of code as follows: library(cluster) data(iris) mydata<-iris[,1:4] maxk<-15# at most 15 clusters myindex<-rep(0,maxk) # hold the si