Thanks Uwe, Your strata suggestion works, thank you, but it has created a dataset of random rows but without the data, other columns involved. You see I would further like to use this random sample for a DFA (lda) analysis. Can you suggest how I would use the strata function to sample a subset of the data.frame?
Thanks Krystyna > Date: Tue, 28 Apr 2009 14:33:22 +0200 > From: lig...@statistik.tu-dortmund.de > To: kagola...@hotmail.com > CC: r-help@r-project.org > Subject: Re: [R] Random Sample with Unique function > > In order to use stratified sampling, either try to implement it yourself > or use the "sampling" package and its function strata() as in: > > s1 <- strata(cc, stratanames="ID", size=rep(1, 20), method="srswr") > > then you will get 1 observation for each ID. Note that it is not > important to use "with replacement" in your case, since you only sample > 1 obervation for each stratum. > > Uwe Ligges > > > > > Krystyna Golabek wrote: > > Dear R-users > > > > I have a dataset of 243 lines with replicate information for 20 different > > individuals (ID). > > I would like to randomly sample this dataset 100 times with a selection of > > unique IDs in each sample. > > > > First to create a random sample I have; > > > > cc<-read.table(blah.blah.blah) > > names(cc) > > [1] "CALL" "CONTEXT" "ORDER" "ID" "STATUS" > > > > s1<-cc[sample(1:243,20,replace=TRUE),] > > > > This code samples 20 rows from the dataset but can anyone help me write the > > code to request unique(ID) in this sample? > > > > Thank you so much for your time and help. > > > > Krystyna Golabek > > > > > > > > _________________________________________________________________ > > > > > > [[alternative HTML version deleted]] > > > > ______________________________________________ > > R-help@r-project.org mailing list > > https://stat.ethz.ch/mailman/listinfo/r-help > > PLEASE do read the posting guide http://www.R-project.org/posting-guide.html > > and provide commented, minimal, self-contained, reproducible code. _________________________________________________________________ [[alternative HTML version deleted]] ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
