Why not use 'split' and get all the groups at once: result <- split(Calandra, list(Calandra$Day, Calandra$Season, drop = TRUE)
On Tue, Mar 27, 2012 at 7:43 AM, Ivan Calandra <ivan.calan...@u-bourgogne.fr> wrote: > Hi HJ, > > Take a look at ?"&"; this is probably what you're looking for. > > What you could also do is: > Calender[Calender$Day=='Wd' & Calender$Season=="Winter", ] # notice the > last comma > > This will subset directly without using which(); it might be helpful to you. > > HTH, > Ivan > > -- > Ivan CALANDRA > Université de Bourgogne > UMR CNRS/uB 6282 Biogéosciences > 6 Boulevard Gabriel > 21000 Dijon, FRANCE > +33(0)3.80.39.63.06 > ivan.calan...@u-bourgogne.fr > http://biogeosciences.u-bourgogne.fr/calandra > > > Le 27/03/12 12:32, HJ YAN a écrit : > >> Dear R-help, >> >> My dataset (which is a data frame, called 'Calender' here) includes 365 >> rows representing 365 days for a year. One column ('Season')contains >> factor data representing seasons, e.g. spring, summer, autumn and winter. >> Another column (called 'Day') contains data representing wether the day >> is >> a working day (I use 'Wd' for short here)or weekend (I use 'Wkend' for >> short here). >> >> >> I want to seperate the index of the working days and weekends for each >> season. I used R commend "which" before for one criteria, for example, if >> I >> use... >> >> >> WdIndex<-which(Calender$Day=='Wd') >> >> that will gives a set of indeices of working days in the year. >> >> I wonder in R could I use a combination of something such as 'AND' , 'OR' >> (e.g. in MySQL) to set 'multi-criteria' when selecting data. So for >> example... >> >> WinterWdIndex<-which(Calender$Day=='Wd' AND Calender$Season=="Winter") >> >> >> I know the above syntax is wrong, and I checked '?which' which did not >> give >> me an answer and also tried '?AND' but seems it doesn`t exist at all... >> >> >> Many thanks! >> HJ >> >> [[alternative HTML version deleted]] >> >> ______________________________________________ >> R-help@r-project.org 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. >> >> > > ______________________________________________ > R-help@r-project.org 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. -- Jim Holtman Data Munger Guru What is the problem that you are trying to solve? Tell me what you want to do, not how you want to do it. ______________________________________________ R-help@r-project.org 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.
