ummmm...
One of the S language's great strengths is the variety and flexibility of
it's data structures. It pays to familiarize yourself with them. So if x is
already a dataframe ("dataset" is a rather unhelpful description), then
row.names(x) <- x$label
x[c("fun","food"),]
will extract the rows you want (to be suitably assigned by you, of course).
Incidentally, the row names typically could have been set when you first
read the data in (e.g. via ?read.table() and friends).
If x is not a dataframe, then your should make it one, and ?data.frame will
tell you how, depending on what it actually is.
I repeat: learn about R's data structures and how to use them if you wish to
take full advantage of the language and its power (and avoid the
unnecessary, though correct (mod the typo), manipulations described in the
reply below).
-- Bert Gunter
-----Original Message-----
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On
Behalf Of Jorge Ivan Velez
Sent: Wednesday, April 23, 2008 4:48 PM
To: Dirkheld
Cc: r-help@r-project.org
Subject: Re: [R] select rows from data based on a vector of char strings
Try this,
x="label freq1 freq2
news 54 35
fun 37 21
milk 19 7
food 3 3"
yourdata=read.table(textConnection(x),header=TRUE)
attached(yourdata)
flist<-c("fun","food")
yourdata[label %in% flist,]
I hope this helps,
Jorge
On Wed, Apr 23, 2008 at 3:13 AM, Dirkheld <[EMAIL PROTECTED]>
wrote:
>
> Hi,
>
> I have loaded a dataset in R :
> data =
>
> label freq1 freq2
> news 54 35
> fun 37 21
> milk 19 7
> food 3 3
> .... etc
>
> And I have a vector
> flist<-c("fun","food")
>
> Now I want to use the vector 'flist' for selecting these values from
> 'data'
> so that I get the following dataset :
> label freq1 freq2
> fun 37 21
> food 3 3
>
> When I do 'data$label==flist[1]' I get 'F T F F', so it works for one item
> in the char vector flist.
> But, when I do 'data$label==flist' I get 'F F F F' while I expected 'F T F
> T'. It seems that I can't perform this action with a vector of
> charstrings?
>
> Is there an other way to do so?
>
> --
> View this message in context:
>
http://www.nabble.com/select-rows-from-data-based-on-a-vector-of-char-string
s-tp16832735p16832735.html
> Sent from the R help mailing list archive at Nabble.com.
>
> ______________________________________________
> R-help@r-project.org 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.
>
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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.
