Hello, Thanks John and David. I ll look into your suggestions and I ll ensure I post more details the next time.
Thanks, Vyshnnavi On Jul 7, 2015 8:19 AM, "David L Carlson" <dcarl...@tamu.edu> wrote: > As John suggests, more information and some sample data would help. I > haven't used loocv, but here is a simple example of leave one out cross > validation with simple linear regression. This does not eliminate the loop, > but uses lapply() which makes specifying the loop simpler. The results of > the 40 regressions are stored in a list called results and results.coef > contains the intercept and slope for each regression in a matrix. > > > set.seed(42) > > x <- rnorm(40, 10, 2) > > y <- x + rnorm(40, 0, 2) > > results <- lapply(1:40, function(i) lm(y[-i] ~ x[-i])) > > results.coef <- t(sapply(results, coef)) > > summary(results.coef) > (Intercept) x[-i] > Min. :-0.1477 Min. :0.8408 > 1st Qu.: 0.2032 1st Qu.:0.9830 > Median : 0.2613 Median :0.9883 > Mean : 0.2933 Mean :0.9866 > 3rd Qu.: 0.3240 3rd Qu.:0.9959 > Max. : 1.9160 Max. :1.0245 > > ------------------------------------- > David L Carlson > Department of Anthropology > Texas A&M University > College Station, TX 77840-4352 > > -----Original Message----- > From: R-help [mailto:r-help-boun...@r-project.org] On Behalf Of John Kane > Sent: Monday, July 6, 2015 6:53 PM > To: Vyshnnavi Parthasarathy; r-help@r-project.org > Subject: Re: [R] Leave one out procedure - R > > > Hi Vyshnnavi, > > I'd suggest having a look at > http://stackoverflow.com/questions/5963269/how-to-make-a-great-r-reproducible-example > and http://adv-r.had.co.nz/Reproducibility.html for some hints on how to > ask questions on the R-help List. > > At the moment I don't think you have supplied enough information, code, > and data for people to easily answer your questions. > > BTW if you are supplying sample data the best way is to use the dput() > function. It provides an exact copy of the data set that you are working > with. > > Sorry not to be of any substantive help. > > > > John Kane > Kingston ON Canada > > > > -----Original Message----- > > From: vyshnnavia...@gmail.com > > Sent: Mon, 6 Jul 2015 08:56:52 -0700 > > To: r-help@r-project.org > > Subject: [R] Leave one out procedure - R > > > > Hello, > > I am still in the process of familiarizing myself with R, pardon me if > > this > > is basic. I want to run a leave one out procedure for a 40 member > > dataset. > > At the moment I am doing it via a simple for loop. I wanted to know if > > there is a superior way to do it. I read about the loocv command here - > > http://artax.karlin.mff.cuni.cz/r-help/library/DMwR/html/loocv.html. > > Since > > I need to save the output generated in each iteration, I am not very sure > > how exactly to implement the same using the loocv command. If you could > > give me an insight into how to do it/ suggest quicker ways to do leave > > one > > out cross validation, it would be really helpful! > > > > Thanks, > > Vyshnnavi > > > > [[alternative HTML version deleted]] > > > > ______________________________________________ > > R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see > > 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. > > ____________________________________________________________ > GET FREE 5GB EMAIL - Check out spam free email with many cool features! > Visit http://www.inbox.com/email to find out more! > > ______________________________________________ > R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see > 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. > [[alternative HTML version deleted]] ______________________________________________ R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see 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.
