That's kind of hard to follow without example data, but have you looked at merge() ?
On Wed, Feb 2, 2011 at 1:31 PM, Ross Dunne <dunn...@tcd.ie> wrote: > Hello, thank you all for your patience and time > > I am essentially trying to get disorganised data into long form for linear > modelling. > > I have 2 dataframes "rec" and "book" > > Each row in "book" needs to be pasted onto the end of several of the rows of > "rec" according to two variables in the row:" MRN" and "COURSE" which match. > > I have tried the following and variations thereon to no avail: > > </code> > #for each line of the recovery dataframe > #insert the one line of the "book" dataset that corresponds to the MRN AND > the course-of-treatment (COURSE) > > #get the mrn and course from the first line of the recovery dataframe (rec) > > i=1 > newlist=list() > colnames(newlist)=colnames(book) > for ( i in 1:dim(rec)[1]) { > > mrn=as.numeric(as.vector(rec$MRN[i])); > course=as.character(rec$COURSE[i]); > > ## find the corresponding row in the book dataframe > ## by generating a logical vector and using > ## it to access "book" > > get.vector<-as.vector(((as.numeric(as.vector(book$MRN))==mrn) & > (as.character(book$COURSE)==course))) > > #gives you a vector of logicals (works) > > newlist[i]<-book[get.vector,] ### (doesn't work) > > i=i+1; > } > </code> > > If anyone has any suggestions on > > 1)getting this to work > 2) making it more elegant (or perhaps just less clumsy) > > If I have been unclear in any way I beg your pardons. > > I do understand I haven't combined any data above, I think if I can generate > a long-format dataframe I can combine them all on my own > > Ross Dunne > MB MRCPsych > ross.du...@tcd.ie > > ________________________________ -- Sarah Goslee http://www.functionaldiversity.org ______________________________________________ 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.