[R] fpc package - computing silhouette value returns error

[Ziqi Zhang]

Hi
I am using R to do clustering and compute a number of cluster 
statistics. Below are my code. I do not understand why I get the error:

"Error in summary(silhouette(clustering[ss[[i]]], dx)) : error in 
evaluating the argument 'object' in selecting a method for function 
'summary': Error in round(x) : non-numeric argument to mathematical 
function"

Any suggestsion highly appreciated!
Code:
--------------
library(fpc)
require(graphics)
distance <- dist(USArrests, "euclidean")
hc <-hclust(distance, "average")
distcritmulti(USArrests, hc, criterion="asw", fun="dist", 
metric="euclidean")
-------------



-- 
Ziqi Zhang
Research Associate
Department of Computer Science
University of Sheffield


---
This email has been checked for viruses by Avast antivirus software.