[R] binary representation of an integer?

[Peter Dalgaard BSA]

Thomas Lumley <thomas at biostat.washington.edu> writes:

> And this one works up to 2^32-1 but returns a string with leading zeros
> 
> binarys<-function(i) {
> a<-2^(31:0)
> b<-2*a
> sapply(i,function(x) paste(as.integer((x %% b)>=a),collapse=""))
> }
> 
> Either could be improved, but it's probably not worth much effort.

And there's also:

bb<-function(i) if (i) paste(bb(i %/% 2), i %% 2, sep="") else ""

which works for all integer 0 < i < 2^54 on IEEE machines. 

-- 
   O__  ---- Peter Dalgaard             Blegdamsvej 3  
  c/ /'_ --- Dept. of Biostatistics     2200 Cph. N   
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