Petr, Thanks, I shall store all this away for reference and have a look at the posting guide.
I didn't expect it to be as complicated as it has turned out. As you will see from my post to Sian, my pressing problem was solved by replacing the "&" with an "|" in the sample code I gave. Graham On 08/09/06, Petr Pikal <[EMAIL PROTECTED]> wrote: > > Hi > > On 8 Sep 2006 at 10:33, Graham Smith wrote: > > Date sent: Fri, 8 Sep 2006 10:33:49 +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 again, but the data is GQ1, Max is a variable (column) > > > > So I have used > > > > by(GQ1[,"Max"], list(GQ1$Status), summary) > > > > Which is very good, and is better than the way I did it before by > > summarising for each status level individually, but that still isn't > > combing the data for Status == "Expert" and Status = "Ecol" > > > > So at the moment the status variable has 3 levels Expert, Ecol and > > Stake, > > look at ?factors how to deal with factors, if your variable is not a > factor (see ?str) than turn it to one. > > x<-sample(letters[1:3], 20, replace=T) #character > x.f<-as.factor(x) #turn to factor > > x.f > [1] b c b a c a c a a a a a b c c c b b c b > Levels: a b c > > levels(x.f)<-c("x","x","y") #rename levels > > x.f > [1] x y x x y x y x x x x x x y y y x x y x > Levels: x y > > > > > > I want to analsye that at two levels: Expert and Ecol combined into a > > new level called "AllEcol" and the exsiting level "Stake" > > so in your case something like > > GQ1$statusComb<-factor(GQ1$status, labels=c("AllEcol","AllEcol", > "Stake")) > > shall do it. Beware of label ordering!!! > > BTW. It had been good if you provided a usable example, as stated in > posting guide. Many times trying to elaborate an example I will solve > the problem myself. > > HTH > Petr > > > > > It is this combining the levels that has got me stuck. > > > > Thanks again, > > > > Graham > > > > On 08/09/06, Petr Pikal <[EMAIL PROTECTED]> wrote: > > > > > > Sorry, I did not notice that in your case Max is not a function but > > > your data. So probably > > > > > > by(Max[, your.columns], list(Max$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] > > > > > > > > > > [[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.