[R] removing for loop

[Peter Dalgaard]

vincent at 7d4.com writes:

> Dear Rusers,
> 
> Trying to reduce my for loops addiction,
> could somebody tell me if there are ways to simplify
> (and perhaps accelerate ?) the following line
> 
> for (i in 1:N) for (j in 1:N) m[i,j] = b[i]-b[j];
> 
> (where m is a NxN matrix and b a vector of length N)
> 
> Thanks for any hint.

m <- outer(b, b, "-") 

-- 
   O__  ---- Peter Dalgaard             Øster Farimagsgade 5, Entr.B
  c/ /'_ --- Dept. of Biostatistics     PO Box 2099, 1014 Cph. K
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