Message-ID: <4C46DA33-B063-4982-827E-82DB0AE43B2E@comcast.net>
Date: 2011-11-22T18:47:55Z
From: David Winsemius
Subject: Removing rows in dataframe w'o duplicated values
In-Reply-To: <CALsYQZdrb_x95HdtFGP5Pf=XkLLRDoJ1+neA24AXBys=mOVvGA@mail.gmail.com>
On Nov 22, 2011, at 12:43 PM, AC Del Re wrote:
> Hi,
>
> Is there an easy way to remove dataframe rows without duplicated
> values of
> a specified column ('id')? e.g.,
>
> dat <- data.frame(id = c(1,1,1,2,3,3), value = c(5,6,7,4,5,4),
> value2 =
> c(1,4,3,3,4,3))
> dat
>
> id value value2
> 1 1 5 1
> 2 1 6 4
> 3 1 7 3
> 4 2 4 3
> 5 3 5 4
> 6 3 4 3
> dat[ave(dat$id, dat$id, FUN=length) >1, ]
id value value2
1 1 5 1
2 1 6 4
3 1 7 3
5 3 5 4
6 3 4 3
>
>
> This is sample data and the real data has hundreds of rows. In this
> case, only row 4 does not have a duplicated id and I would like to
> remove it without using:
>
>
> dat$id[4] <- NULL
>
>
> Any help is appreciated!
>
>
> AC
>
> [[alternative HTML version deleted]]
>
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David Winsemius, MD
West Hartford, CT