[R] How to convert two-dimensional function to matrix?

Peter Dalgaard p.dalgaard at biostat.ku.dk
Tue Aug 1 17:06:55 CEST 2006


JeeBee <JeeBee at troefpunt.nl> writes:

> On Tue, 01 Aug 2006 16:23:46 +0200, Lothar Schmid wrote:
> 
> > I'd like to convert a two-dimensional function f(x,y) to a matrix m,
> > so that m[x,y] = f [x,y]. How can I achieve this?
> 
> Maybe this helps.
> I create an empty matrix first, then apply f to the indices.
> 
> f <- function(x, y) { 1000*x + y }
> 
> ( m <- matrix( data = NA, nrow = 5, ncol = 4 ) )
> ( m <- f(row(m), col(m)) )

outer(1:5, 1:4, f)


-- 
   O__  ---- Peter Dalgaard             Øster Farimagsgade 5, Entr.B
  c/ /'_ --- Dept. of Biostatistics     PO Box 2099, 1014 Cph. K
 (*) \(*) -- University of Copenhagen   Denmark          Ph:  (+45) 35327918
~~~~~~~~~~ - (p.dalgaard at biostat.ku.dk)                  FAX: (+45) 35327907



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