Mohammad A. Chaudhary
2004-Dec-17 22:38 UTC
[R] Confidence Intervals from Bootstrap Replications
Hi All: I have to compute bootstrap confidence intervals, the statistic (incremental cost effectiveness ratio) is computed from two samples (intervention and control) of different sizes. All the bootstrap functions that I have seen use one dataset as argument. I may go ahead and get the desired number of bootstrap replications separately. I would appreciate if you could point me to a source of a bootstrap function (if available) that takes the B bootstrap replications and other descriptive statistics and can get me the confidence intervals. Please write me if I have not been clear in explaining my problem. Regards, Ashraf ___________________________________ M. Ashraf Chaudhary, Ph.D. Associate Scientist/Biostatistician Department of International Health Disease Prevention and Control Program Johns Hopkins University Bloomberg School of Public Health 615 North Wolfe Street, Room W5506 Baltimore MD 21205 mchaudha@jhsph.edu Phone: (410) 502-0741/Fax: (410) 502-6733 http://faculty.jhsph.edu/?F=Mohammad&L=Chaudhary [[alternative HTML version deleted]]
See , e.g. section 8.3 "The two-sample problem" of Efron and Tibshirani's AN INTRODUCTION TO THE BOOTSTRAP. It makes it clear there why one just bootstrap samples independently from the two separate samples. The "strata" argument of boot() in the boot package allows one to do such independent sampling and use the capabilities of that function. -- Bert Gunter Genentech Non-Clinical Statistics South San Francisco, CA "The business of the statistician is to catalyze the scientific learning process." - George E. P. Box> -----Original Message----- > From: r-help-bounces at stat.math.ethz.ch > [mailto:r-help-bounces at stat.math.ethz.ch] On Behalf Of > Mohammad A. Chaudhary > Sent: Friday, December 17, 2004 2:39 PM > To: r-help at stat.math.ethz.ch > Subject: [R] Confidence Intervals from Bootstrap Replications > > Hi All: > > I have to compute bootstrap confidence intervals, the statistic > (incremental cost effectiveness ratio) is computed from two samples > (intervention and control) of different sizes. All the bootstrap > functions that I have seen use one dataset as argument. I may go ahead > and get the desired number of bootstrap replications > separately. I would > appreciate if you could point me to a source of a bootstrap > function (if > available) that takes the B bootstrap replications and other > descriptive > statistics and can get me the confidence intervals. Please > write me if I > have not been clear in explaining my problem. Regards, > > Ashraf > > > > ___________________________________ > > M. Ashraf Chaudhary, Ph.D. > > Associate Scientist/Biostatistician > > Department of International Health > > Disease Prevention and Control Program > > Johns Hopkins University Bloomberg School of Public Health > > 615 North Wolfe Street, Room W5506 > > Baltimore MD 21205 > > > > mchaudha at jhsph.edu > > Phone: (410) 502-0741/Fax: (410) 502-6733 > > http://faculty.jhsph.edu/?F=Mohammad&L=Chaudhary > > > > > > > [[alternative HTML version deleted]] > > ______________________________________________ > R-help at stat.math.ethz.ch mailing list > https://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide! > http://www.R-project.org/posting-guide.html >