this 'ifelse' usage looks promising. thank you very much. On Thu, May 7, 2009 at 3:12 PM, Patrick Burns <pbu...@pburns.seanet.com>wrote:
> If you haven't seen it yet, > 'The R Inferno' may be of use > to you. > > > Patrick Burns > patr...@burns-stat.com > +44 (0)20 8525 0696 > http://www.burns-stat.com > (home of "The R Inferno" and "A Guide for the Unwilling S User") > > miraceti wrote: > >> Hi, I am still not familiar with vectorization. >> Could you help with making this for loop more efficient? >> The code is trying to make a Q matrix for a multidimensional state space >> with specific conditions. >> >> thanks >> Mira >> >> >> tmp = 0:(maxvals[1]) >> for(i in 2:nchars) { >> tmp <- outer(tmp, 0:(maxvals[i]), FUN="paste", sep=".") >> } >> states = tmp >> stateidx = array(1:length(states), dim=dim(states)) >> transition <- matrix(data=0, nrow=length(states), ncol=length(states)) >> >> findstatedim <- function(x) which(stateidx==x, arr.ind = TRUE) >> manhattandistance <- function(x,y) >> sum(abs(findstatedim(x)-findstatedim(y))) >> >> for(i in 1:length(states)) { >> for (j in 1:length(states)) { >> if (manhattandistance(i, j)==1) { >> if (sum(findstatedim(i)-findstatedim(j)) < 0) { >> transition[i,j] = "gain" >> if (findstatedim(i)[findstatedim(i)-findstatedim(j) == -1] == >> 1) >> { >> transition[i,j] = "firstgain" >> } >> } >> else { >> transition[i,j] = "loss" >> } >> } >> } >> } >> transition >> >> [[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. >> >> >> [[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.
