Hello, I'm using the R package called mvpart, which is about the multivariate regression trees. The function I wrote is: mrt1<- mvpart(coefmat~sChip+sScreen+sMem,data=mixdata, xv="pick", plot.add=TRUE,uniform=TRUE,which=4,all=TRUE,xadj=2,yadj=2,rsq=TRUE,big.pts=TRUE,wgt.ave.pca=TRUE,legend=TRUE,bars=F, pca=TRUE) where "coefmat" is a matrix(of dimension N*K) to store the coefficients of my functional data object; and the predictors in the formula are all vectors of length N. Since I set the option "bars=T" and "pca = T", I get the barplot at the node of each leaves on my tree, and a pca plot. My question is that what is the barplot about? Is it the histogram of the rows of "coefmat" in the node, or the value for any predictor? Also I get a messy pca plot. I guess each "square" (it's not quite square) in the pca plot represents a node in the tree; but what are the squres representing? Many thanks for any help on this. -Shu