Hi if you use summary aggregate probably will not work and tapply have to be called differently
tapply(seq(along=Max[,1]), list(Max$Status), function(i, x) summary(x[i]), x=Max[,one.column]) or you can use by by(Max[,1:5]), list(Max$Status), summary) or if you do not like the output something like that lll <- lapply(as.list(Max[,your.columns]), function(x) sapply(split(x,Max$Status),summary)) do.call("rbind",lll) or do.call("data.frame",lll) HTH Petr On 8 Sep 2006 at 10:03, Graham Smith wrote: Date sent: Fri, 8 Sep 2006 10:03:51 +0100 From: "Graham Smith" <[EMAIL PROTECTED]> To: "Petr Pikal" <[EMAIL PROTECTED]> Copies to: r-help@stat.math.ethz.ch Subject: Re: [R] subsetting a data set > Petr, > > Thanks I shall have at look at these options. > > Sorry about the confusion with the "Max", in my example "Max" is the > name of the variable that I am summarising. I chose a poor example to > cut and paste form R, not thinking about the obvious confusion this > would cause. > > Thanks again > > Graham > > On 08/09/06, Petr Pikal <[EMAIL PROTECTED]> wrote: > > > > Hi > > > > I am not sure if your Max is the same as max so I am not sure what > > you exactly want from your data. However you shall consult ?tapply, > > ?by, ?aggregate and maybe also ?"[" together with chapter 2 in intro > > manual in docs directory. > > > > aggregate(data[, some.columns], list(data$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] > > > > > > [[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.