Re: [R] subsetting a data set

From: Petr Pikal <petr.pikal_at_precheza.cz>
Date: Fri 08 Sep 2006 - 08:31:12 GMT


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]]
>
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Petr Pikal
petr.pikal@precheza.cz



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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 18:35:58 2006

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