Re: [R] subsetting a data set

From: Petr Pikal <petr.pikal_at_precheza.cz>
Date: Fri 08 Sep 2006 - 09:13:49 GMT

Sorry, I did not notice that in your case Max is not a function but your data. So probably

by(Max[, your.columns], list(Max$status), summary)

is maybe what you want.
HTH
Petr

On 8 Sep 2006 at 10:31, Petr Pikal wrote:

From:           	"Petr Pikal" <petr.pikal@precheza.cz>
To:             	"Graham Smith" <myotisone@gmail.com>, r-help@stat.math.ethz.ch
Date sent:      	Fri, 08 Sep 2006 10:31:12 +0200
Priority:       	normal
Subject:        	Re: [R] subsetting a data set

> Hi
>
> I am not sure if your Max is the same as max so I am not sure what you
> exactly want from your data. However you shall consult ?tapply, ?by,
> ?aggregate and maybe also ?"[" together with chapter 2 in intro manual
> in docs directory.
>
> aggregate(data[, some.columns], list(data$factor1, data$factor2), max)
>
> will give you maximum for specified columns based on spliting the data
> according to both factors
>
> Also connection summary with max is not common and I wonder what is
> your output in this case. I believe that there are six same numbers.
> However R is case sensitive and maybe Max does something different
> from max. In my case it throws an error.
>
> HTH
> Petr
>
> On 8 Sep 2006 at 8:06, Graham Smith wrote:
>
> Date sent: Fri, 8 Sep 2006 08:06:16 +0100
> From: "Graham Smith" <myotisone@gmail.com>
> To: r-help@stat.math.ethz.ch
> Subject: [R] subsetting a data set
>
> > I have a data set called GQ1, which has 20 variables one of which is
> > a factor called Status at thre levels "Expert", "Ecol" and "Stake"
> >
> > I have managed to evaluate some of the data split by status using
> > commands like:
> >
> > summary (Max[Status=="Ecol"])
> >
> > BUT how do I produce asummary for Ecol and Expert combined, the
> > only example I can find suggsts I could use
> >
> > summary (Max[Status=="Ecol"& Status=="Expert"]) but that doesn't
> > work.
> >
> > Additionally on the same vein, if I cannot work out how to create a
> > new data set that would contain all the data for all the variables
> > but only for the data where Status = Ecol, or where status equalles
> > Ecol and Expert.
> >
> > I know this is yet again a very simple problem, but I really can't
> > find the solution in the help or the books I have.
> >
> > Many thanks,
> >
> > Graham
> >
> > [[alternative HTML version deleted]]
> >
> > ______________________________________________
> > R-help@stat.math.ethz.ch mailing list
> > https://stat.ethz.ch/mailman/listinfo/r-help
> > PLEASE do read the posting guide
> > http://www.R-project.org/posting-guide.html and provide commented,
> > minimal, self-contained, reproducible code.
>
> Petr Pikal
> petr.pikal@precheza.cz
>
> ______________________________________________
> R-help@stat.math.ethz.ch mailing list
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide
> http://www.R-project.org/posting-guide.html and provide commented,
> minimal, self-contained, reproducible code.

Petr Pikal
petr.pikal@precheza.cz



R-help@stat.math.ethz.ch mailing list
https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code. Received on Fri Sep 08 19:17:36 2006

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