[R] The R Inferno

[Peter Dalgaard]

Ajay ohri wrote:
> excellent adaptation of Dante and R with real common sense tips to help
> beginners especially ..goes to the blogroll......
> now if only i could get tips to sort a 5 column * 1 million rows  dataset in
> less than ..eternity....

Er, that's a fairly short eternity:

 > x <- data.frame(rnorm(1e6),rnorm(1e6),rnorm(1e6),rnorm(1e6),rnorm(1e6))
 > names(x) <- letters[1:5]
 > system.time(y <- x[order(x$a),])
    user  system elapsed
   3.259   0.160   3.435
 > head(y)
                a          b          c           d           e
227944 -4.418977  0.9635349  0.2477897 -0.10172584  0.09840375
492006 -4.327607 -1.4967631 -0.3467700  0.53053492 -0.80043595
89830  -4.285324 -2.0491949 -2.2024725 -0.34946013 -0.63538249



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