[R] besoin d'aide

Tony Plate tplate at blackmesacapital.com
Wed Apr 16 18:18:26 CEST 2003

The function merge() is like the "join" operation in relational data bases 
- it's much more powerful than mere concatenation (and thus often much 
slower, especially on large tables.)

To merely concatenate tables together, use rbind() (to concatenate by rows) 
or cbind() (to concatenate by columns).

If you do need the power of merge(), but it is too slow for your purposes 
you may be able to write a special-purpose function in R that does just 
only you need and much more quickly -- such is the nature of the S language 
-- it is very powerful, but the powerful general-purpose functions can 
often be quite slow in particular cases.

Hope this helps, and apologies if I have not completely understood your 

-- Tony Plate

At Wednesday 03:39 PM 4/16/2003 +0200, Erwan BARRET wrote:
>J'aimerais savoir si la fonction merge() est la seule disponible pour 
>concatener des tableaux de données?
>Est-ce normal que l'exécution soit lente?
>R-help at stat.math.ethz.ch mailing list

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