Have you looked at subset?

For example, 
subset(mdat, !(mdat$C.1== 11)) 

You will have to add your other cases and there may be a better way to programmatically get it done, but maybe this will help you get started.

--- On Thu, 3/5/09, Lazarus Mramba <LMramba@kilifi.kemri-wellcome.org> wrote:
From: Lazarus Mramba <LMramba@kilifi.kemri-wellcome.org>
Subject: [R] Dropping rows conditionally
To: r-help@r-project.org
Date: Thursday, March 5, 2009, 12:18 AM

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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