Hi, The following code, from Angelo Canty article on line "Resampling Methods in R: the boot Package, 2002", works fine for Angelo Canty using R 2.6.0 on Windows XP. It also works for me using R 1.2.1 and S-PLUS 2000 on Windows XP after installing the S-PLUS bootstrap library, with slight differences in my outputs. > library(boot)> library(survival) > set.seed(12345)> mel <- melanoma[melanoma$ulcer==1,] > mel$cens <- 1*(mel$status==1) > mel.cox <- coxph(Surv(time, status==1)~thickness, + data=mel) > mel.surv <- survfit(mel.cox) > mel.cens <- survfit(Surv(time-0.001*(status==1),status!=1)~1, + data=mel) > mel.fun <- function(d) { + cox <- coxph(Surv(time, status==1)~thickness, + data=d) + cox$coefficients} > mel.boot.con <- censboot(mel, mel.fun, R=999, sim="cond", + F.surv=mel.surv, G.surv=mel.cens, + cox=mel.cox, index=c(1,8)) > mel.boot.con CONDITIONAL BOOTSTRAP FOR CENSORED DATA Call: censboot(data = mel, statistic = mel.fun, R = 999, F.surv = mel.surv, G.surv = mel.cens, sim = "cond", cox = mel.cox, index = c(1, 8)) Bootstrap Statistics : original bias std. error t1* 0.09967665 0.03579701 0.04973614 I want to apply the Fast bootstrap method from Salibian-Barrera and Zamar (2003) and Salibian-Barrera, M., Van Aels, S. and Willems, G. (2007) to the previous example, i.e., to produce a confidence interval for the exponent of the coefficient of tumour thickness in the Melanoma dataset . Moreover, I want to compare the performance of the Fast bootstrap with that of the classical bootstrap, which requires of course computing power and time. How I can adjust the previous code to do what I want. I asked Angelo Canty for helping me to do this, but he told me that he is afraid that he does not know anything about the Fast Bootstrap to which I refer. He suspects that one could force his boot package to do something like this but he is not sure if that would be possible through censboot or not. Although my problem does seem interesting for him, he is afraid that he is not currently in a position to take on any new collaborations. He remains available to answer any questions about the boot package itself as it is currently written, he just does not have the time to consider including new elements into the library at this time. I think that the paper of Salibian-barrera and Zamar (2003) is not published till now. Now I do not have an electronic copy of this paper draft but I have a hard copy. And so I can send you an attachment including some written sections from this paper "Fast and Stable Bootstrap Methods for Statistics Defined by Estimating Equations, Salibian-Barrera and Zamar (2003)". Please tell me If you want to send you this attachment, which can also includes what I want to do, and what I suggest. I need the adjusted code bad. I hope you help me. If you can not help me, please guide me to anyone who can help me. Thank you in advance. Alyaa Mohammad El-wakf Assistant Lecturer Department of Applied Statistics and Insurance Faculty of Commerce Mansoura University Egypt --------------------------------- [[alternative HTML version deleted]]
Martin Maechler
2008-Jan-26 12:38 UTC
[R] sending the same e-mail many times (was "no subject")
Dear Alyaa, you've now sent this message in many different forms to the R-help mailing list. The fact that you did not get a response may very well be related to the way you asked your question, but also that it probably is not an easy question to answer. But sending your e-mail repeatedly to *several thousand* people is considered *very* impolite.>>>>> "aw" == alyaa wakf <alyaawakf2002 at yahoo.com> >>>>> on Sat, 26 Jan 2008 02:12:25 -0800 (PST) writes:aw> Hi, The following code, from Angelo Canty article on line "Resampling Methods in R: the boot Package, 2002", works fine for Angelo Canty using R 2.6.0 on Windows XP. aw> It also works for me using R 1.2.1 and S-PLUS 2000 on Windows XP after installing the S-PLUS bootstrap library, with slight differences in my outputs. [.....................] the footer here tells us that you still don't follow the posting guide (namely, not sending HTML) even though you may have started doing so by trying to produce reproducible code. Regards, Martin Maechler, ETH Zurich aw> --------------------------------- aw> [[alternative HTML version deleted]] aw> ______________________________________________ aw> R-help at r-project.org mailing list aw> https://stat.ethz.ch/mailman/listinfo/r-help aw> PLEASE do read the posting guide http://www.R-project.org/posting-guide.html aw> and provide commented, minimal, self-contained, reproducible code.