Hi Jim! Thank you so much for the very helpful hints!! I am learning 'split' now and it seems very useful..
HJ On Tue, Mar 27, 2012 at 12:58 PM, jim holtman <jholt...@gmail.com> wrote: > 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<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<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<http://www.r-project.org/posting-guide.html> > and provide commented, minimal, self-contained, reproducible code. > [[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.
