[R] Removing duplicated rows within a matrix, with missing data as wildcards

[Petr Pikal]

Hi

its a bit tricky but

dup<-apply(x, 2, duplicated) #which are dupplucated
isna<-apply(x, 2, is.na) #which are na
check<-dup|isna # which are both

and here is your result

x[rowSums(check)!=3,]
     [,1] [,2] [,3]
[1,]    1    3    2
[2,]    2    1    3
[3,]    3    2   NA


Regards
Petr




On 8 Mar 2007 at 10:14, stacey thompson wrote:

Date sent:      	Thu, 8 Mar 2007 10:14:37 -0500
From:           	"stacey thompson" <stacey.lee.thompson at gmail.com>
To:             	r-help at stat.math.ethz.ch
Subject:        	[R] Removing duplicated rows within a matrix,
	with missing data as wildcards

> I'd like to remove duplicated rows within a matrix, with missing data
> being treated as wildcards.
> 
> For example
> 
> > x <- matrix((1:3), 5, 3)
> > x[4,2] = NA
> > x[3,3] = NA
> > x
> 
>      [,1] [,2] [,3]
> [1,]    1    3    2
> [2,]    2    1    3
> [3,]    3    2   NA
> [4,]    1   NA    2
> [5,]    2    1    3
> 
> I would like to obtain
> 
>       [,1] [,2] [,3]
> [1,]    1    3    2
> [2,]    2    1    3
> [3,]    3    2   NA
> 
> >From the R-help archives, I learned about unique(x) and
> >duplicated(x).
> However, unique(x) returns
> 
> > unique(x)
> 
>      [,1] [,2] [,3]
> [1,]    1    3    2
> [2,]    2    1    3
> [3,]    3    2   NA
> [4,]    1   NA    2
> 
> and duplicated(x) gives
> 
> > duplicated(x)
> 
> [1] FALSE FALSE FALSE FALSE  TRUE
> 
> I have tried various na.action 's but with unique(x) I get errors at
> best.
> 
> e.g.
> > unique(x, na.omit(x))
> 
> Error: argument 'incomparables != FALSE' is not used (yet)
> 
> How I might tackle this?
> 
> Thanks,
> 
> -stacey
> 
> -- 
> -stacey lee thompson-
> Stagiaire post-doctorale
> Institut de recherche en biologie végétale
> Université de Montréal
> 4101 Sherbrooke Est
> Montréal, Québec H1X 2B2 Canada
> stacey.thompson at umontreal.ca
> 
> ______________________________________________
> R-help at stat.math.ethz.ch 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.

Petr Pikal
petr.pikal at precheza.cz