[R] Multi matrix row-wise mapply?

Peter Dalgaard P.Dalgaard at biostat.ku.dk
Tue Oct 21 11:51:35 CEST 2008


cmr.Pent at gmail.com wrote:
> Hi group!
>
> Suppose I have 2 matrices A and B of equal dimensions.
> I want to apply a function f to all corresponding pairs of rows from A
> and B in an efficient manner.
> Basically, I want
>
> mapply(f, data.frame(A), data.frame(B))
>
> but for rows.
>
> How do I do it?
>
>   

Transpose them?

Or, back to basics:

sapply(1:nrow(A), function(i) f(A[i,],B[i,]) )



-- 
   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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