Re: [R] question about matrix one column values matching a vector of values

From: Henrique Dallazuanna <wwwhsd_at_gmail.com>
Date: Sun, 09 Mar 2008 20:35:25 -0300

Use %in% indeed of '=='

a[a[,1] %in% b,]

On 09/03/2008, Waverley <waverley.paloalto_at_gmail.com> wrote:
> Hi,
>
> I have a matrix
> a = matrix (1:16, 4, 4)
> b = c (2,3)
>
> I want to find out which rows of a, where a[,1] equals any values of b?
>
> I know that if b is only one value, e.g, b=2, then what I want is a[a[,1] ==
> 2,]
>
> But what about if it is not one value but a vector of values?
>
> Thanks much in advance.
>
> --
> Waverley @ Palo Alto
>
> ______________________________________________
> R-help_at_r-project.org mailing list
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> PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.
>

-- 
Henrique Dallazuanna
Curitiba-Paraná-Brasil
25° 25' 40" S 49° 16' 22" O

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Received on Sun 09 Mar 2008 - 23:37:33 GMT

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