Hello, I am having a problem with the "outer" function.
I am using R 1.9.1 on Windows 2000. My problem may be described as follows: I have a function f of 3 variables and 3 vectors, aa, bb and cc. I would like to evaluate this function in a 3-dimensional grid of points corresponding to all combinations of the elements of the 3 vectors. For example, if aa<-c(1,2) bb<-c(3,4) cc<-c(5,6) then I'd like a loop which evaluates the 2^3 values f(1,3,5), f(1,3,6), f(1,4,5), f(1,4,6),f(2,3,5),f(2,3,6),f(2,4,5) and f(2,4,6). The easy way to do this would be to nest 3 for-next loops, but I hope that I more elegant way is possible, especially because in the actual problem at hand I need to make such evaluations with a function of n parameters. I was hoping to create a 3-dimensional array consisting of 3-element vectors, and then be able to use a single loop to get through all the values. I expected to do this with outer(outer(aa,bb,c),cc,c) However, I get the following error when I use the "outer" function with the concatenate function "c" as the third argument: >outer(aa,bb,c) Error in outer(aa,bb,c) : dim<- : dims [product 4] do not match the length of object [8] Does anyone know a way to get around this? I have consulted the R manuals without results, and I can't seem to find the problem described in the mail archives either. Thanks, Alexander ______________________________________________ [EMAIL PROTECTED] mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html
