R help - Jun 2010 - output from the gbm package

HI, Dear Greg and R community,

I have one question about the output of gbm package. the output of Boosting
should be f(x), from it , how to calculate the probability for each
observations in data set?

SInce it is stochastic, how can guarantee that each observation in training
data are selected at least once? IF SOME obs are not selected, how to
calculate the training error?

Thanks?


-- 
Sincerely,
Changbin
--

Changbin Du
DOE Joint Genome Institute
Bldg 400 Rm 457
2800 Mitchell Dr
Walnut Creet, CA 94598
Phone: 925-927-2856

	[[alternative HTML version deleted]]

Use predict(my.gbm,type="response")

If you use bag.fraction=1.0 then all observations are guaranteed to be
used. For other choices, and assuming that you are doing a reasonable
number of iterations, like 1000, then there is only a negligible chance
that an observation won't be selected.

________________________________________
From: Changbin Du [mailto:changbind at gmail.com] 
Sent: Tuesday, June 15, 2010 11:06 AM
To: Ridgeway, Greg
Cc: r-help at r-project.org
Subject: output from the gbm package

HI, Dear Greg and R community,

I have one question about the output of gbm package. the output of
Boosting should be f(x), from it , how to calculate the probability for
each observations in data set?

SInce it is stochastic, how can guarantee that each observation in
training data are selected at least once? IF SOME obs are not selected,
how to calculate the training error?

Thanks?


-- 
Sincerely,
Changbin 
--

Changbin Du
DOE Joint Genome Institute
Bldg 400 Rm 457
2800 Mitchell Dr
Walnut Creet, CA 94598
Phone: 925-927-2856


__________________________________________________________________________

This email message is for the sole use of the intended r...{{dropped:6}}