Laura Quinn <laura at env.leeds.ac.uk> wrote:
I am wishing to investigate the temporal evolution of the pca: if we assume that every 50 rows of my data frame is representitive of, for instance, 1 day of data, I am hoping to automate a process whereby a pca is performed on every 50 rows of data and the loading for PC1 and PC2 for each variable (i.e. each column) is represented as a point on a plot - so a years' data will be represented as two lines (representing PC1 and PC2) on a time series plot for each variable.
Hi Laura, You might try to take a look at the "between", "within" and "pta" functions of the ade4 package : http://pbil.univ-lyon1.fr/ade4html/between.html http://pbil.univ-lyon1.fr/ade4html/within.html http://pbil.univ-lyon1.fr/ade4html/pta.html They can be used to analyse a data set with this kind of structure. Choosing how to analyse it depends on what you are looking for. Jean
Jean Thioulouse - Labo de Biometrie et Biologie Evolutive, UMR CNRS 5558
Universite Lyon 1, 43 Boulevard du 11 Novembre 1918, Batiment G. Mendel
69622 Villeurbanne Cedex, France. Tel/Fax : (33) 4 72 43 27 56
http://pbil.univ-lyon1.fr/JTHome.html