You're absolutely right, Marc.
Thanks > From: marc_schwa...@me.com > To: jholt...@gmail.com > Date: Thu, 18 Jun 2009 15:23:06 -0500 > CC: r-help@r-project.org; alexandre_geor...@hotmail.com > Subject: Re: [R] Random number datasets help > > Quite true Jim, however I focused on his request and not his code, > presuming that he did not realize what he was doing as a consequence > of the nested loops. > > Perhaps Alexandre can provide clarification? > > Regards, > > Marc > > On Jun 18, 2009, at 2:46 PM, jim holtman wrote: > > > That is not what his 'for' loops are doing. He is iterating through > > all > > combinations and would have created 784. So his problem statement > > did not > > match the code that he sent. > > > > On Thu, Jun 18, 2009 at 2:12 PM, Marc Schwartz > > <marc_schwa...@me.com> wrote: > > > >> Alexandre did say 28 datasets, not 784 (28 * 28).... > >> > >> Thus, either: > >> > >> mapply(rnorm, n = 500, mean = a1, sd = a2) > >> > >> or > >> > >> apply(cbind(a1, a2), 1, function(x) rnorm(500, x[1], x[2])) > >> > >> > >> HTH, > >> > >> Marc Schwartz > >> > >> On Jun 18, 2009, at 12:51 PM, Henrique Dallazuanna wrote: > >> > >> Try this also: > >>> > >>> a <- expand.grid(a1, a2) > >>> x <- mapply(rnorm, n = 500, mean = a[,1], sd = a[,2]) > >>> > >>> On Thu, Jun 18, 2009 at 2:10 PM, Alexandre Lockhart < > >>> alexandre_geor...@hotmail.com> wrote: > >>> > >>> > >>>> Hello: > >>>> > >>>> My problem is that I have a data frame of means, and a data frame > >>>> of > >>>> standard deviations which match up to each mean. I have been > >>>> trying to > >>>> create 500 random numbers in a given dataset for each mean/sd > >>>> combination, > >>>> but I am only able to generate the last value in each data set to > >>>> create > >>>> one > >>>> dataset (there should be 28 in all). Examining my code, what can I > >>>> change > >>>> to generate 28 datasets based on respective mean and sds? > >>>> > >>>> > >>>> > >>>> a1<- > >>>> c > >>>> (178.07,178.28,178.08,177.74,177.04,178.17,177.58,57.71,59.6,60.92,59.48,59.32,61.59,59.94,28.9,29.82,30.73,25.68,27.93,28.98,29.76,123.48,127.27,127.8,127.2,127.13,126.71,125.5 > >>>> > >>>> ) > >>>> > >>>> > >>>> a2<- > >>>> c > >>>> (1.69,1.3,1 > >>>> ,. > >>>> 18,1.53,1.31,1.35,1.83,1.56,1.12 > >>>> ,. > >>>> 74,1.48,1.67,1.53 > >>>> ,.95,.87,0.03,1.12,1.95,1.22,1.04,1.64,1.83,1,1,1.08,1.35,2.37) > >>>> for(i in 1:length(a1)) > >>>> for(j in 1:length(a2)) > >>>> x<-rnorm(500,mean=a1[i],sd=a2[j]) > >>>> > >>>> Thank you, > >>>> > >>>> Agl > > ______________________________________________ > 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. _________________________________________________________________ Bing™ brings you maps, menus, and reviews organized in one place. Try it now. a=TEXT_MLOGEN_Core_tagline_local_1x1 [[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.
