grouped colSums without for loops?

* PGP Signed by an unknown key: 03/18/2008 at 06:22:03 AM
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 (http://sociologi.cjb.net) <hans at sociologi.cjb.net>
Q. What is that strange attachment in this mail?
A. My digital signature, see www.gnupg.org for info on how you could
   use it to ensure that this mail is from me and has not been
   altered on the way to you.
* Unknown Key
* 0x7050614E (L)