help with vector construction

One approach is to use the fact that vectors are automatically
replicated to the correct length when subscripting, so you can do
something like:
my.matrix[ c(FALSE,TRUE,FALSE), 3 ] 
To get every 3rd element starting at the 2nd element, and the 3rd
column.

Hope this helps,
Gregory (Greg) L. Snow Ph.D.
Statistical Data Center
Intermountain Healthcare
greg.snow at intermountainmail.org
(801) 408-8111

> -----Original Message-----
> From: r-help-bounces at stat.math.ethz.ch 
> [mailto:r-help-bounces at stat.math.ethz.ch] On Behalf Of Juan 
> Pablo Fededa
> Sent: Thursday, July 05, 2007 11:30 AM
> To: r-help at stat.math.ethz.ch
> Subject: [R] help with vector construction
> 
> Hi all,
> 
> I want to make a vector with the third column of a matrix, 
> but only for the
> 2+3n rows of the matrix, with n being an entire number from 0 
> to a million.
> How can I do that in an easy way?
> Thanks in advance,
> 
> Juan Pablo
> 
> 	[[alternative HTML version deleted]]
> 
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help with vector construction

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