Hi Stefan, >> Is it possible to combine both PCAs in order to get only one set of >> eigenvectors?
Yes there is: statis() in the ade4 package is probably what you want. In short, it does a k-table analysis that will give you a common ordination/position. It also shows how each time-set deviates from that common position. RV-coeff. showing how well the two tables match each other &c. Excellent graphical summaries... The method is quite complex, but if you read French then there is some very good documentation on their site: http://pbil.univ-lyon1.fr/ADE-4 Here you will also find a couple of papers (in English) on the method. There's also a list. Stephane (Dray) replies to many of the questions and writes and speaks English well. HTH, Mark. Stefan Koenig wrote: > > Dear all: > > Subjects were measured two times (t1 and t2) on different variables (v1 > ... vn). > Between t1 and t2 there was an experimental manipulation. I computed two > PCAs for time-points t1 and t2. > > Is it possible to combine both PCAs in order to get only one set of > eigenvectors? Due to the experimental manipulation measurement values on > time points t1 and t2 changed for each subject. > > Many thanks > Stefan > -- > > ______________________________________________ > 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. > > -- View this message in context: http://www.nabble.com/How-to-combine-to-PCAs-tp17665060p17667990.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.
