Re: [R] Newbie Question -- Remove entire column in a matrix

From: Charles C. Berry <cberry_at_tajo.ucsd.edu>
Date: Tue, 15 Jan 2008 09:33:40 -0800

On Tue, 15 Jan 2008, My Coyne wrote:

>
>
> I'm ordering "The R Book" and hope to learn a lot more about R. In a
> meantime, I have a matrix of digits and I would like to look for a column
> that contains zeroes and remove the entire column from the matrix. I can
> write a piece of R code to do that (and it works); however, I think the
> R-experts have more tricks to do such a 'simple' thing.

Is one of these what you want?

         new.mat <- mat[ , colSums( mat==0 ) == 0 ]

         new.mat <- mat[ , colSums( mat==0 ) < nrow(mat) ]

HTH, Chuck

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> Many thanks in advance.
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> --My Coyne
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Charles C. Berry                            (858) 534-2098
                                             Dept of Family/Preventive Medicine
E mailto:cberry_at_tajo.ucsd.edu	            UC San Diego
http://famprevmed.ucsd.edu/faculty/cberry/ La Jolla, San Diego 92093-0901

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https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code. Received on Tue 15 Jan 2008 - 17:36:57 GMT

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