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.