[R] barplot and pca plot in mvpart/rpart

[shu zhang]

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