Assistance with boot() Package

An embedded and charset-unspecified text was scrubbed...
Name: not available
URL: <https://stat.ethz.ch/pipermail/r-help/attachments/20100103/6d755ad1/attachment.pl>

Good Evening R Community:

I believe I understand the basics of using the boot() bootstrap 
resampling function in the boot() package. I have not had any 
trouble creating a boot.object to which I apply the boot.ci() 
function to calculate one or all of the available confidence 
intervals.

What I am not sure about is if this set of functions can generate 
more than one confidence interval of one or all of the types 
available.

I have a large data set (n=133,456) data set from which I would like 
to remove random samples of different sizes and then calculate 95% 
confidence intervals for the mean, 10% trimmed mean and median. I 
would like to determine how often the confidence intervals generated 
by boot.ci() contain the mean, 10% trimmed mean and median of the 
large data set.

I have looked at some examples for using the boot() and boot.ci() 
functions to generate confidence intervals for the intercept and 
predictive variables from a regression model, but I do not, or 
cannot I suppose, determine how I can generate more than one set of 
normal, basic, percentile and BCa confidence intervals using these 
two functions.
Well, it can be done easily.  Studying the book for which 'boot' is 
support software would be a good start, but a hint is to look at the 
'index' argument to boot.ci: basically boot() can be called with a 
'statistic' which returns a vector, then boot.ci() called on each of 
the components of interest.  There is an example in MASS (the book) on 
pp 225-6.
I am running R version 2.9.2 on an IBM T61 laptop. My OS is Win XP 
professional SP 3, and the machine has a 1.99 GHz processor with 
2.99 GB of RAM. The version of the boot() package I am running is 
1.2-41.

Thanks in advance for taking the time to help me.

Adam

	[[alternative HTML version deleted]]

______________________________________________
R-help at r-project.org mailing list
https://stat.ethz.ch/mailman/listinfo/r-help
PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.
PLEASE do -- no HTML mail for a start, and please update your R.
Brian D. Ripley,                  ripley at stats.ox.ac.uk
Professor of Applied Statistics,  http://www.stats.ox.ac.uk/~ripley/
University of Oxford,             Tel:  +44 1865 272861 (self)
1 South Parks Road,                     +44 1865 272866 (PA)
Oxford OX1 3TG, UK                Fax:  +44 1865 272595
An embedded and charset-unspecified text was scrubbed...
Name: not available
URL: <https://stat.ethz.ch/pipermail/r-help/attachments/20100104/55f90495/attachment.pl>