Søren Højsgaard <[EMAIL PROTECTED]> writes: > In data OME in MASS I would like to extract the first 5 observations per > subject (=ID). So I do > > library(MASS) > OMEsub <- split(OME, OME$ID) > OMEsub <- lapply(OMEsub,function(x)x[1:5,]) > unsplit(OMEsub, OME$ID) > > - which results in > > [[1]] > [1] 1 1 1 1 1 > [[2]] > [1] 30 30 30 30 30 > [[3]] > [1] low low low low low > Levels: N/A high low > [[4]] > [1] 35 35 40 40 45 > [[5]] > [1] coherent incoherent coherent incoherent coherent > Levels: coherent incoherent > [[6]] > [1] 1 4 0 1 2 > > ............ > > [[1094]] > [1] 4 5 5 5 2 > [[1095]] > [1] 100 100 100 100 100 > [[1096]] > [1] 18 18 18 18 18 > [[1097]] > [1] N/A N/A N/A N/A N/A > Levels: N/A high low > There were 50 or more warnings (use warnings() to see the first 50) > > warnings() > Warning messages: > 1: number of items to replace is not a multiple of replacement length > 2: number of items to replace is not a multiple of replacement length > 3: number of items to replace is not a multiple of replacement length > .... > > According to documentation unsplit is the reverse of split, but I must be > missing a point somewhere... Can anyone help? Thanks in advance. Søren
It only works if the first argument is or could have resulted from a split on the second argument. That is clearly not the case when you are creating subvectors. I have on occasion wanted an unsplit that worked without the 2nd argument as in unsplit(l, rep(seq(along=l), sapply(l,length)) ) but if you think about it, it's not really doing anything that do.call("c",l) or do.call("rbind",l) won't do. -- O__ ---- Peter Dalgaard Øster Farimagsgade 5, Entr.B c/ /'_ --- Dept. of Biostatistics PO Box 2099, 1014 Cph. K (*) \(*) -- University of Copenhagen Denmark Ph: (+45) 35327918 ~~~~~~~~~~ - ([EMAIL PROTECTED]) FAX: (+45) 35327907 ______________________________________________ R-help@stat.math.ethz.ch mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html