[R] Dropping rows conditionally

David Winsemius dwinsemius at comcast.net
Thu Mar 5 13:46:56 CET 2009


There are functions for this purpose:

?na.omit   # dispays help page for na.fail, na.omit,  na.exclude,   
na.pass

-- 
David Winsemius
On Mar 5, 2009, at 1:18 AM, Lazarus Mramba wrote:

>
> Dear R-help team,
>
> I am getting addicted to using R but keep on getting many challenges  
> on the way especially on data management (data cleaning).
>
> I have been wanting to drop all the rows if there values are  `NA'  
> or have specific values like 1 or 2 or 3.
>
>
> mdat <- matrix(1:21, nrow = 7, ncol=3, byrow=TRUE,
>               dimnames = list(c("row1",  
> "row2","row3","row4","row5","row6","row7"),
>                               c("C.1", "C.2", "C.3")))
> mdat<-data.frame(mdat)
> mdat
>
>      C.1 C.2 C.3
> row1   1   2   3
> row2   4   5   6
> row3   7   8   9
> row4  10  11  12
> row5  13  14  15
> row6  16  17  18
> row7  19  20  21
>
> I want to say drop row if value=1 or value =11 or value =20
>
> How do I do that?
>
>
> Kind regards,
> Lazarus Mramba
> Junior Statistician
> P.O Box 986, 80108,
> Kilifi, Kenya
> Mobile No. +254721292370
> Tel: +254 41 522063
> Tel: +254 41 522390
> (office extension : 419)
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