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$status), summary) is maybe what you want. HTH Petr On 8 Sep 2006 at 10:31, Petr Pikal wrote: From: "Petr Pikal" <[EMAIL PROTECTED]> To: "Graham Smith" <[EMAIL PROTECTED]>, r-help@stat.math.ethz.ch Date sent: Fri, 08 Sep 2006 10:31:12 +0200 Priority: normal Subject: Re: [R] subsetting a data set > Hi > > I am not sure if your Max is the same as max so I am not sure what you > exactly want from your data. However you shall consult ?tapply, ?by, > ?aggregate and maybe also ?"[" together with chapter 2 in intro manual > in docs directory. > > aggregate(data[, some.columns], list(data$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" <[EMAIL PROTECTED]> > 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 > [EMAIL PROTECTED] > > ______________________________________________ > 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 [EMAIL PROTECTED] ______________________________________________ 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.