Thanks a lot everyone - it's been extremely helpful! Dimitri On Mon, Sep 21, 2009 at 3:16 PM, Jorge Ivan Velez <jorgeivanve...@gmail.com> wrote: > > Hi Dimitri, > Try also either > index[apply(index, 1, function( x ) length( unique( x ) ) == 4 ),] > or > # install.packages('e1071') > require(e1071) > permutations(4) > HTH, > Jorge > > On Mon, Sep 21, 2009 at 2:14 PM, Dimitri Liakhovitski <> wrote: >> >> Hello, dear R-ers! >> >> I built a data frame "grid" (below) with 4 columns. I want to exclude >> all rows that have equal values in ANY 2 columns. Here is how I am >> doing it: >> >> index<-expand.grid(1:4,1:4,1:4,1:4) >> dim(index) >> # Deleting rows that have identical values in any two columns (1 line of >> code): >> >> index<-index[!(index$Var1==index$Var2)&!(index$Var1==index$Var3)&!(index$Var1==index$Var4)&!(index$Var2==index$Var3)&!(index$Var2==index$Var4)&!(index$Var3==index$Var4),] >> dim(index) >> index >> >> >> I was wondering if there is a more elegant way of doing it - because >> as the number of columns increases, the amount of code one would have >> to write increases A LOT. >> >> Thank you very much for any suggestion! >> >> >> >> -- >> Dimitri Liakhovitski >> Ninah.com >> dimitri.liakhovit...@ninah.com >> >> ______________________________________________ >> 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. > >
-- Dimitri Liakhovitski Ninah.com dimitri.liakhovit...@ninah.com ______________________________________________ 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.