Re: [R] grouped colSums without for loops?

From: Hans Ekbrand <>
Date: Tue, 18 Mar 2008 12:22:08 +0100

On Tue, Mar 18, 2008 at 05:57:59AM -0500, jim holtman wrote:
> Is this what you want?
> > lapply(split(d, d$foo), function(x) colSums(x[,-1]))

Yes! Thank you! the *apply functions seem very powerful, thanks again for giving me a hint on how to use them.

Hans Ekbrand ( <>
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Received on Tue 18 Mar 2008 - 11:25:28 GMT

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