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Message-ID: <200005031546.LAA16284@t3.mscf.uky.edu>
Date: 2000-05-03T15:46:42Z
From: Mai Zhou
Subject: :?alternative to loop
In-Reply-To: <391003F9.B4C44DB@univ-orleans.fr> from "nicolas baurin" at May 03, 2000 12:48:26 PM

Many people suggested apply(). It works for many functions.
But if you just need sum(), take a look at rowsum(), it should be 
faster.

Note also, the function rowsum() in Splus2000 is not as fast as in R.

Mai Zhou
> 
> Hello to all R people,
> 
> for the application of a function to each column of a matrix (ex:
> function sum()), i'd like to know if there is a simpler (and faster)
> alternative to a loop like :
> 
> for (i in 1: ncol(m)){sum(m[i])}
> 
> Thanks in advance,
> Cordialement,
> --
> Nicolas Baurin
> 
> Doctorant
> Institut de Chimie Organique et Analytique, UPRES-A 6005
> Universit? d'Orl?ans, BP 6759
> 45067 ORLEANS Cedex 2, France
> Tel: (33+) 2 38 49 45 77
> 
> 
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