R help - Jun 2010 - gbm function

 Hello
 
I have questions about gbm package.  It seems we have to devide data to two part
(training set and test set) for first.
 
1- trainig set for running of gbm function
2- test set for gbm.perf   
 
is it rigth? 
I have 123 sample that I devided 100 for trainig and 23 for test.
 
So, parameter of cv.folds in gbm function is for what?
 
Thanks alot
Azam
 
 
 


      
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On Wed, 23-Jun-2010 at 12:05AM -0700, azam jaafari wrote:

|> ?Hello
|> ?
|> I have questions about gbm package.??It seems we have to?devide data to
two part (training?set and test set) for first.
|> ?
|> 1- trainig set for?running of gbm function
|> 2- test set for?gbm.perf???
|> ?
|> is it rigth? 
|> I have 123 sample that I devided 100 for trainig and 23 for test.
|> ?
|> So, parameter of?cv.folds?in gbm function is for what?

There's quite a lot to be known about how to use those functions.  The
vignette gives a bit of an idea, but I came across this article which
helped me work out how to use them.



 A working guide to boosted regression trees J. Elith,
 J. R. Leathwick, T. Hastie Journal of Animal Ecology Volume 77 ,
 Issue 4 , Pages802 - 813 Journal compilation ? 2008 British
 Ecological Society


HTH

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