David C. Howell wrote: > I am writing a resampling program for multiple regression using lm(). I > resample the data 10,000 times, each time extracting the regression > coefficients. At present I extract the individual regression > coefficients using > > brg = lm(Newdv~Teach + Exam + Knowledge + Grade + Enroll) > bcoef[i,] = brg$coef > > This works fine. > > But now I want to extract the t tests on these coefficients. I cannot > find how these coefficients are stored, if at all. When I try > attributes(brg) > I do not find the t values as the attributes of the object. Typing > summary(brg) will PRINT the coefficients, their standard errors, t, and > the associated probability. I would like to type something like > tcoeff[i,] = brg$tvalue > but, of course, tvalue doesn't exist. > > Is there a simple way to extract, or compute if necessary, these values?
summary(brg)$coefficients[,3] str(summary(brg)) is sometimes helpful for figuring out how to extract something. Also, you might have a look at John Fox's document on bootstraping regression models if you don't already know about it: http://cran.r-project.org/doc/contrib/Fox-Companion/appendix-bootstrapping.pdf > Thanks, > Dave Howell -- Chuck Cleland, Ph.D. NDRI, Inc. 71 West 23rd Street, 8th floor New York, NY 10010 tel: (212) 845-4495 (Tu, Th) tel: (732) 512-0171 (M, W, F) fax: (917) 438-0894 ______________________________________________ R-help@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 and provide commented, minimal, self-contained, reproducible code.