Dear Helpers I have a simulated sample frame and i have sampled from it using three methods and now i want to calculate the statistics but i only get the population parameters.For example i need to get the summary,length,std.error,etc. this is just a simplified example. H <- matrix(rnorm(100, mean=50000, sd=5000)) sampleframe=data.frame(type=c(rep("H",100)),value=c(H)) sampleframe str=strata(sampleframe,c("type"),size=c(20,), method="srswor") sample.strat<-getdata(sampleframe,str) sample.strat length(H) i get: length(H) [1] 100 Desire to get: length(H) [1] 20 Best Regards [[alternative HTML version deleted]]