[R] transforming character categories

Peter Dalgaard p.dalgaard at biostat.ku.dk
Sun Jun 28 14:06:18 CEST 2009


Gabor Grothendieck wrote:
> If you only want to convert them to unique numbers then
> 
> as.numeric(factor(x))
> 
> will do that.

Or, use it directly for indexing, as in c(1000,2500,4173,3700)[factor(x)]

DEPENDING on LEVEL ORDER, mind you! So make sure you know what the order 
is or set it yourself using factor(x, levels=...)

-- 
    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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