R help - Nov 2006 - random forest importance calculation

Hi all,

I am using random forest (regression) and I am having trouble calculating
the variable importance for my object (RF).  Here is what I tried:

RF$importance
and
importance(RF)

The thing is that the reported %incMSE is different between those two. I
understand that the function importance() does some re-scaling and averaging
of the results, but does that mean that the order of variables with respect
to importance changes after that?

This is what I got:
> importance(RFcebus)
              %IncMSE IncNodePurity
vbio1        28.34672      77950703
vbio4        29.34845      71261614
vbio12       43.62222     126822944
vbio15       34.47683     151702649
vmodis       19.69951      18413449
vfootprint   23.31656      67756166
vgeotopo     30.06409      55710807
vcost_slope  51.85601     210008585
vlight        0.00000             0
vaccess30   182.90648     136540782
> RFcebus$importance
              %IncMSE IncNodePurity
vbio1       13171.572      77950703
vbio4       11617.453      71261614
vbio12      18330.536     126822944
vbio15      16786.781     151702649
vmodis       1736.843      18413449
vfootprint  10619.448      67756166
vgeotopo     8619.964      55710807
vcost_slope 25811.859     210008585
vlight          0.000             0
vaccess30   11037.952     136540782

Any suggestions would be appreciatted.

Thanks,

Naiara.

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