Dear all, This is my first time using this listserv and I am seeking help from the expert. OK, here is my question, I am trying to use impute.knn function in impute library and when I tested the sample code, I got the error as followingt: Here is the sample code: library(impute) data(khanmiss) khan.expr <- khanmiss[-1, -(1:2)] ## ## First example ## if(exists(".Random.seed")) rm(.Random.seed) khan.imputed <- impute.knn(as.matrix(khan.expr)) ## ## khan.imputed$data should now contain the imputed data matrix x<-khan.imputed$data Here are the results: > library(impute) > data(khanmiss) > khan.expr <- khanmiss[-1, -(1:2)] > ## ## First example > ## if(exists(".Random.seed")) rm(.Random.seed) > khan.imputed <- impute.knn(as.matrix(khan.expr)) Cluster size 2308 broken into 1448 860 Done cluster 1448 Done cluster 860 > ## ## khan.imputed$data should now contain the imputed data matrix > x<-khan.imputed$data Error in khan.imputed$data : $ operator is invalid for atomic vectors It seems that khan.imputed$data is empty!! Why is that?? Any help is appreciated, Jianying Li