[R] Finding not-matching rows in tables

[Petr Pikal]

Hi

you can use
%in%

tabella[tabella$x %in% tab$x,]

to select rows which are in both and

tabella[!(tabella$x %in% tab$x),]
to select only non matching ones


HTH
Petr


On 7 Feb 2007 at 0:00, Vittorio wrote:

Date sent:      	Wed, 7 Feb 2007 14:23:45 +0100 (GMT+01:00)
From:           	Vittorio <vdemart1 at tin.it>
To:             	r-help at stat.math.ethz.ch
Subject:        	[R] Finding not-matching rows in tables
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> I have these two dataframes in which 'id' is the key field
> > tabella
> 
> id          nome
> 1   1      PIEMONTE
> 2   2  VALLED'AOSTA
> 3   3     
> LOMBARDIA
> 4   4      TRENTINO
> 5   5        VENETO
> 6   6        FRIULI
> 
> AND
> 
> > tab
>    id          nome
> 1   1      PIEMONTE
> 2   2  VALLED'AOSTA
> 3   3     LOMBARDIA
> 4   4      TRENTINO
> 5  25     CAMPANIA
> 6  28       
> LAZIO
> 
> Is there any R-one-command able to select the only rows of tab 
> that are not present in tabella, matching the two tables on 'id'?  The
> result should be
> 
> 5  25     CAMPANIA
> 6  28       LAZIO
> 
> I was able to 
> obtain this results by means of the merge command merging the two
> tables and selecting according to the <NA> fields, therefore in two
> steps....
> 
> Ciao
> Vittorio
> 
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Petr Pikal
petr.pikal at precheza.cz