Also new values can be easy calculated from prcomp object: Data <- scale(iris[,1:4],center=TRUE,scale=TRUE) iris.pc <- prcomp(Data)
# Explained variation (iris.pc$sdev^2/sum(iris.pc$sdev^2))*100 # Loadings iric.pc$rotation #Scores iris.pc$x #Fitted Values for each PC # Xfit = T*P^t PCfit <- function (i,pcdata) {PCI <- pcdata$x[,i]%*%t(pcdata$rotation[,i])} Fitted <- lapply (c(1:4),PCfit,pcdata=iris.pc) for ( i in c(1:4) ) { assign (paste("IrisPC",i,sep=""),Fitted[[i]])} #Residuals EPC1 <- round(Data - IrisPC1,3) EPC2 <- round(Data - (IrisPC1+IrisPC2),3) EPC3 <- round(Data - (IrisPC1+IrisPC2+IrisPC3),3) EPC4 <- round(Data - (IrisPC1+IrisPC2+IrisPC3+IrisPC4),3) # 0 Andris Jankevics On Piektdiena, 10. Novembris 2006 05:58, Renaud Lancelot wrote: > See ?rconst in package ade4. You will need to fit the PCA with > dudi.pca (same package). > > Best, > > Renaud > > 2006/11/9, Poizot Emmanuel <[EMAIL PROTECTED]>: > > Dear all, > > > > I did performed a PCA analysis (using prcomp function) on a data matrix. > > Then I would like to reconstruction part of the original data set using > > only specifics and choosen eigenvectors. > > I would like to know if there is a function under R witch can perform > > this reconstruction. > > Regards > > > > -- > > > > ------------------------------------------------ > > Emmanuel Poizot > > Cnam/Intechmer > > B.P. 324 > > 50103 Cherbourg Cedex > > > > Phone (Direct) : (00 33)(0)233887342 > > Fax : (00 33)(0)233887339 > > ------------------------------------------------ > > > > > > > > ______________________________________________ > > 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 and provide commented, > > minimal, self-contained, reproducible code. ______________________________________________ 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 and provide commented, minimal, self-contained, reproducible code.