Or, to show the "power of the R language", so to speak, and assuming that Dave is correct, there is no need to use a for() loop:
xmat <- matrix( rnorm( 27*5, rep(mu,5), rep(sig,5) ) , nrow=27) To verify that I've created the vectors in the right order, and converted to a matrix in the right order, try this: mu <- 1:27 sig <- rep(1,27) x.matrix<-matrix(0,nrow=27,ncol=5) for(i in 1:27){ # x.matrix[i,j]<-rnorm(5,mu[i],sig[i]) ## Dave's suggestion: x.matrix[i, ] <- rnorm(5,mu[i],sig[i]) # since 'j' doesn't exist } ## loop not necessary: xmat <- matrix( rnorm( 27*5, rep(mu,5), rep(sig,5) ) , nrow=27) plot( rowMeans(x.matrix), rowMeans(xmat)) abline(0,1) -- Don MacQueen Lawrence Livermore National Laboratory 7000 East Ave., L-627 Livermore, CA 94550 925-423-1062 On 3/27/14 12:39 PM, "David Winsemius" <dwinsem...@comcast.net> wrote: > >On Mar 27, 2014, at 4:31 AM, IZHAK shabsogh wrote: > >> i try to generate 27*5 matrix of observation using the following code >>but is given error >> kindly assist and correct the problem >> >> >> x1<-c(-1,0,1,-1,0,1,-1,0,1,-1,0,1,-1,0,1,-1,0,1,-1,0,1,-1,0,1,-1,0,1) >> x2<-c(-1,-1,-1,0,0,0,1,1,1,-1,-1,-1,0,0,0,1,1,1,-1,-1,-1,0,0,0,1,1,1) >> x3<-c(-1,-1,-1,-1,-1,-1,-1,-1,-1,0,0,0,0,0,0,0,0,0,1,1,1,1,1,1,1,1,1) >> mu<-50+5*(x1^2+x2^2+x3^2) >> sig<-100+5*((x1-0.5)^2+x2^2+x3^2) >> x.matrix<-matrix(0,nrow=27,ncol=5) >> for(i in 1:27){ > >Perhaps, instead: > > x.matrix[i, ]<-rnorm(5,mu[i],sig[i]) # since 'j' doesn't exist > >> x.matrix[i,j]<-rnorm(5,mu[i],sig[i]) >> } >> >> >> Thanks >> Ishaq >> [[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. > >David Winsemius >Alameda, CA, USA > >______________________________________________ >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.