Dear Jean,

Thank you, expand.grid was the function I needed.

/johannes


> 
> See 
>         ?expand.grid 
> 
> For example, 
>         df <- expand.grid(L=L, AR=AR, SO=SO, T=T) 
>         df$y <- fun(df$L, df$AR, df$SO, df$T) 
> 
> Jean 
> 
> 
> Johannes Radinger wrote on 01/13/2012 12:28:46 PM:
> 
> > Hello,
> > 
> > probably it is quite easy but I can get it: I have
> > mulitple numeric vectors and a function using
> > all of them to calculate a new value:
> > 
> > L <- c(200,400,600)
> > AR <- c(1.5)
> > SO <- c(1,3,5)
> > T <- c(30,365)
> > 
> > fun <- function(L,AR,SO,T){
> >    exp(L*AR+sqrt(SO)*log(T))
> > }
> > 
> > How can I get an array or dataframe where
> > all possible combinations of the factors are listed
> > and the new value is calculated.
> > 
> > I thought about an array like:
> > array(NA, dim = c(3,1,3,2), dimnames=list(c(200,400,600),c(1.5),c(1,
> > 3,5),c(30,365)))
> > 
> > but how can I get the array populated according to the function?
> > 
> > As I want to get in the end a 2D dataframe I probably will use the 
> > melt.array()
> > function from the reshape package or is there another way to get simple such
> > a "full-factorial" dataframe with all possible combinations?
> > 
> > Best regards,
> > Johannes


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