It's requested to cc the list on our back-and-forths so that i) you can get help faster (I was moving all yesterday and it's a Hallmark holiday in the US today) since others may respond; ii) others can benefit by reading the archives.
On Sun, Jun 17, 2012 at 4:34 AM, Giulia Motta <letamo...@hotmail.com> wrote: > > > the problem is that i want to do something like > http://www.eco.uc3m.es/~jgonzalo/teaching/PhDTimeSeries/gonzalojec94.pdf in > page 13 > with theta= 0.5, sigma = 0.5, a1=0 a2=-1 beta= 1 > and so i have to give a name (ewt, ezt) at the erratic component of my > multivariate normal > ________________________________ > From: letamo...@hotmail.com > To: > Subject: RE: [R] Multivariate Normal and loops > Date: Sun, 17 Jun 2012 09:03:25 +0000 > > > I'm very grateful to you! > But i'm wondering how i can do this, creating a matrix in which i can > numerate every element? > I don't know if i'm clear (probably not). > Thank you very much > Unfortunately, I'm not totally clear as to what you are looking for here. You can add row and column names (labels) with code like rownames(A) <- c("a","cat","dog") and then subscript appropriately: A["cat",] will pull out all columns (the empty index after the comma) in the row labelled "cat". This is all documented in the manual I suggested to you. If there's something else you mean, try being a little clearer (using examples from other programming languages if you know them is always good) and we'll see what we can do. Best, Michael > >> From: michael.weyla...@gmail.com >> Date: Fri, 15 Jun 2012 10:34:05 -0500 >> Subject: Re: [R] Multivariate Normal and loops >> To: letamo...@hotmail.com >> CC: r-help@r-project.org >> >> I don't think you need loops at all actually :-) [The main thing to >> working with R vs. C is "vectorization" -- embrace it now and life >> will be much better] >> >> You could do something like this: >> >> library(MASS) # Provides a multivariate normal distribution >> >> mvrnorm(100, c(1,5), matrix(c(2,1,1,2), ncol = 2)) >> >> This gives you 100 samples of a multivariate normal with mean vector >> (1,5) and covariance matrix >> >> (2, 1, >> 1, 2) >> >> Feel free to tweak as necessary and type ?mvrnorm to see more >> documentation. >> >> Hopefully this gets you started. >> >> For more on vectorization, see the "Introduction to R" that comes with >> R. You can get it by typing help.start() at your command prompt. >> >> Hope this helps, >> Michael >> >> On Fri, Jun 15, 2012 at 9:26 AM, Cassie <letamo...@hotmail.com> wrote: >> > Hi, >> > i'm not english and i'm not very familiar to R, and i'm asking if you >> > can >> > help me. >> > I'm wondering how to create a multivariate normal an then repeat this >> > for a >> > sample of T=1000, and the save this result. >> > Thank you very much for your helping >> > >> > -- >> > View this message in context: >> > http://r.789695.n4.nabble.com/Multivariate-Normal-and-loops-tp4633504.html >> > Sent from the R help mailing list archive at Nabble.com. >> > >> > ______________________________________________ >> > 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. ______________________________________________ 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.
