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Message-ID: <42F392A9.5050700@statistik.uni-dortmund.de>
Date: 2005-08-05T16:24:09Z
From: Uwe Ligges
Subject: Computing sums of the columns of an array
In-Reply-To: <42F390E9.3010301@metahuman.org>

Martin C. Martin wrote:

> Hi,
> 
> I have a 5x731 array A, and I want to compute the sums of the columns.  
> Currently I do:
> 
> apply(A, 2, sum)


colSums(A)

Uwe Ligges


> But it turns out, this is slow: 70% of my CPU time is spent here, even 
> though there are many complicated steps in my computation.
> 
> Is there a faster way?
> 
> Thanks,
> Martin
> 
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