Hello, First, you can try to split your data frame in this way:
list.year<-split(pca, unique(pca$year)) And then apply the principal component analysis over the list "list.year". Regards, Carlos Ortega www.qualityexcellence.es On Tue, Mar 22, 2011 at 12:35 PM, mathijsdevaan <mathijsdev...@gmail.com>wrote: > Hi, > > I am trying to calculate Principal Component Scores per id per year using > the psych package. The following lines provide the scores per obeservation > > pca = data.frame(read.table(textConnection(" id year A B C D > 1001 1972 64 56 14 23 > 1003 1972 60 55 62 111 > 1005 1972 57 51 10 47 > 1007 1972 59 49 7 10 > 1009 1972 65 50 9 32 > 1011 1972 52 58 3 5 > 1013 1972 63 52 9 27 > 1001 1973 65 56 14 25 > 1003 1973 61 55 62 7 > 1005 1973 58 51 10 47 > 1007 1973 60 49 7 19 > 1009 1973 66 50 9 32 > 1011 1973 53 58 3 5 > 1013 1973 64 52 9 28 > 1001 1974 66 56 14 23 > 1003 1974 62 55 62 11 > 1005 1974 59 51 10 46 > 1007 1974 61 49 7 10 > 1009 1974 67 50 9 38 > 1011 1974 54 58 3 5 > 1013 1974 65 52 9 24 > 1001 1975 67 56 1 23 > 1003 1975 63 55 6 1 > 1005 1975 60 51 1 47 > 1007 1975 62 49 7 10 > 1009 1975 68 50 9 32 > 1011 1975 55 58 3 5 > 1013 1975 66 52 9 27"),head=TRUE)) > > library(psych) > pcascores<-principal(pca[,-2], nfactors=1, score=TRUE) > > However, the scores should be based on the observations per year rather > than > the full set of observations. The final output should be a data frame with > 7 > rows (one for each id) and 4 columns (one for each year) filled with the > Principal Component Scores per id per year. Any ideas on how to do this? > > Thanks! > > -- > View this message in context: > http://r.789695.n4.nabble.com/Find-Principal-Component-Score-per-year-tp3396132p3396132.html > Sent from the R help mailing list archive at Nabble.com. > > ______________________________________________ > 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.