Try this:
expand.grid(seq(startpos, endpos, by = diff(c(startpos, endpos)) /
nrow(sr)),
seq(startpos, endpos, by = diff(c(startpos, endpos)) / nrow(sr)))
On Tue, Jan 25, 2011 at 1:29 PM, Alaios <ala...@yahoo.com> wrote:
> Greetings Friends,
> I would be grateful if you can help me undestand how to make my R code more
> efficiently.
>
> I have read in R intoductory tutorial that a for loop is not used so ofter
> (and is not maybe not that efficient) compared to other languages.
>
> So I am trying to build understanding how to get the equivalent of a for
> loop using more R-oriented thinking.
>
> If I got it right one way to do that in R is Vectorize. So I have writen a
> small snippet of code with two nested for loops. I would be grateful if you
> can help me find the equivalent of this code using Vectorize (or any other R
> thinking)
>
> My code takes as input a n*m matrix and prints the x,y coordinates where a
> cells starts and ends.
>
>
>
> remap <- function (sr){
> # Input this funcion takes as arguments
> # sr: map
> startpos<- -1 #
> endpos<- +1 #
> stepx<- (endpos - (startpos)) / nrow(sr)
> stepy<- (endpos - (startpos)) / ncol(sr)
>
> for (i in seq(from=-1,to=1,by=stepx) ) {
> for (j in seq(from=-1,to=1,by=stepx) ){
> cat(' \n',i,j)
> }
>
> }
> }
> sr<-matrix(data=seq(from=1,to=9),nrow=3,ncol=3,byrow=TRUE)
> remap(sr)
>
> Regards
> Alex
>
> ______________________________________________
> R-help@r-project.org mailing list
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> PLEASE do read the posting guide
> http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.
>
--
Henrique Dallazuanna
Curitiba-Paraná-Brasil
25° 25' 40" S 49° 16' 22" O
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