Help with a repeating process

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Help with a repeating process

 I am trying to create a looping function that takes 252 rows of a matrix from 1, then the next 252 rows of a matrix from 1+1, so on and so forth until nrow of the matrix. I am using the for + if loop combo but I seem to be stuck on the if portion. I'm trying to code if so that if the row is less than the last row in matrix ret, it will keep running, else break. Here is what I have so far: for(i in 1:i+252) { + if(ret[<=nrow(ret),]) Any help would be appreciated very very much. Thank you!
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Re: Help with a repeating process

 Perhaps an easier coding that shows what I want would be this: > for(i in 1:nrow(ret)) { + retT=ret[1+i:252+i,]} Thank you so much for your time and help!
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Re: Help with a repeating process

 On Jun 24, 2012, at 11:37 AM, tbowlo wrote: > Perhaps an easier coding that shows what I want would be this: > >> for(i in 1:nrow(ret)) { > + retT=ret[1+i:252+i,]} You should be thinking about what will happen in that indexing   operation when the loop pushes 'i' above nrow(ret)-251 (You may want to look at the 'embed' function, once that is, after you   have correctly sorted out your understanding of the "dimensions" of   this extraction.) > > Thank you so much for your time and help! > > -- > View this message in context: http://r.789695.n4.nabble.com/Help-with-a-repeating-process-tp4634336p4634339.html> Sent from the R help mailing list archive at Nabble.com. And you should learn that rhelp is NOT on Nabble and that the list   rules say that you should be posting context for your   postings  ...even when (or perhaps especially when) you are amending   earlier requests for help. > PLEASE do read the posting guide http://www.R-project.org/posting-guide.html> and provide commented, minimal, self-contained, reproducible code. -- David Winsemius, MD West Hartford, CT ______________________________________________ [hidden email] mailing list https://stat.ethz.ch/mailman/listinfo/r-helpPLEASE do read the posting guide http://www.R-project.org/posting-guide.htmland provide commented, minimal, self-contained, reproducible code.
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Re: Help with a repeating process

 In reply to this post by tbowlo On Sun, Jun 24, 2012 at 08:37:23AM -0700, tbowlo wrote: > Perhaps an easier coding that shows what I want would be this: > > > for(i in 1:nrow(ret)) { > + retT=ret[1+i:252+i,]} Hi. Using your previous description, i think, you mean (1+i):(252+i). Note that this is quite different from 1+i:252+i, which is equivalent to 1 + (i:252) + i.   i <- 10   identical(1+i:252+i, 1 + (i:252) + i)   [1] TRUE Hope this helps. Petr Savicky. ______________________________________________ [hidden email] mailing list https://stat.ethz.ch/mailman/listinfo/r-helpPLEASE do read the posting guide http://www.R-project.org/posting-guide.htmland provide commented, minimal, self-contained, reproducible code.