R help - Sep 2014 - Adjusted R2 for Multivariate Regression Trees (MRT)

Dear fellows,

I am using MVPARTwrap package to built a MRT of 25 pollen samples collected
from 5 different ecosystems, on my analysis I will include adjusted R2.

Based on MVPARTwrap package I want to get adjusted R2 for my MRT for this,
I am using the code below.

#step 1 - Building MRT.
Pre_euro.mvpart <- mvpart(data.matrix(mydata.2) ~ .,5Ecosystems,
margin=0.02, cp=0, xv="pick", xval=nrow(mydata.1), xvmult=100,
which=4)

#step 2- Adjusted R2
R2aGDF(MRT.mite.tree, T=40, tau_const=0.6, 5Ecosystems)

However, if run adjusted R2 code (step 2) 100 times, I will get 100
different results. Which one is correct?

Does anyone can help me? Any help is very welcome.

Cheers.

Jackson Rodrigues

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