Hi, Try this: new1<-as.data.frame(expand.grid(a=a,b=b,c=c)) mat1<-as.matrix(new1[order(new1$a),]) row.names(mat1)<-1:nrow(mat1) mat1 # a b c #1 1 5 1 #2 1 5 6 #3 2 5 1 #4 2 5 6 A.K.
----- Original Message ----- From: Simeon Lisovski <simeon.lisov...@me.com> To: r-help@r-project.org Cc: Sent: Sunday, October 21, 2012 7:05 PM Subject: [R] Parameter Matrix Hallo, I would like to run a model (differential equations) with a whole bunch of parameter combinations. I think the best way of doing this is to put the model function into a loop and set a matrix with the parameters: Each row will represent the parameters for one loop. I know how to compile such a matrix (via another loop, or by using rbind etc.). However I hope you guys may have a much better solution compiling such a matrix very quick and straightforward. Example (very simple): a <- 1:2 b <- 5 c <- seq(1,10,5) The Matrix should be: a b c 1 5 1 1 5 6 2 5 1 2 5 6 Any ideas? Cheers, Simeon ______________________________________________ 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.