why not simply vars=list() for (i in 1:1000) vars[[i]] = var(z[[i]])
On Mon, May 18, 2009 at 6:51 AM, Kon Knafelman <konk2...@hotmail.com> wrote: > > Hi, > >> g=list() >> for(i in 1:1000){z[[i]]=rnorm(15,0,1)} > > I've attempted a similar problem based on the above method. Now, if i want to > find the sample variance, do i go about it like this? > >> for (i in 1:1000)vars[[i]] = sum(z[[i]]) >> vars[[i]] > > the overall sigma squared will just be 1, because the distribution is > standard normal. Is this correct? > > if so, then to find (n-1)S^2/σ^2, > > i will need s=999*sum(vars[[i]]))/1? > > Is this correct, or am i getting lost along the way? > > Thank you >> Date: Wed, 13 May 2009 16:45:22 +0100 >> From: b.rowling...@lancaster.ac.uk >> To: csa...@rmki.kfki.hu >> CC: r-help@r-project.org >> Subject: Re: [R] Simulation >> >> On Wed, May 13, 2009 at 4:26 PM, Gábor Csárdi <csa...@rmki.kfki.hu> wrote: >> > On Wed, May 13, 2009 at 5:13 PM, Debbie Zhang <debbie0...@hotmail.com> >> > wrote: >> >> >> >> >> >> Dear R users, >> >> >> >> Can anyone please tell me how to generate a large number of samples in R, >> >> given certain distribution and size. >> >> >> >> For example, if I want to generate 1000 samples of size n=100, with a >> >> N(0,1) distribution, how should I proceed? >> >> >> >> (Since I dont want to do "rnorm(100,0,1)" in R for 1000 times) >> > >> > Why not? It took 0.05 seconds on my 5 years old laptop. >> >> Second-guessing the user, I think she maybe doesn't want to type in >> 'rnorm(100,0,1)' 1000 times... >> >> Soln - "for" loop: >> >> > z=list() >> > for(i in 1:1000){z[[i]]=rnorm(100,0,1)} >> >> now inspect the individual bits: >> >> > hist(z[[1]]) >> > hist(z[[545]]) >> >> If that's the problem, then I suggest she reads an introduction to R... >> >> Barry >> >> ______________________________________________ >> R-help@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. > > _________________________________________________________________ > Looking to change your car this year? Find car news, reviews and more > http://a.ninemsn.com.au/b.aspx?URL=http%3A%2F%2Fsecure%2Dau%2Eimrworldwide%2Ecom%2Fcgi%2Dbin%2Fa%2Fci%5F450304%2Fet%5F2%2Fcg%5F801459%2Fpi%5F1004813%2Fai%5F859641&_t=762955845&_r=tig_OCT07&_m=EXT > [[alternative HTML version deleted]] > > > ______________________________________________ > R-help@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. > > -- Mike Lawrence Graduate Student Department of Psychology Dalhousie University Looking to arrange a meeting? Check my public calendar: http://tr.im/mikes_public_calendar ~ Certainty is folly... I think. ~ ______________________________________________ R-help@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.