On Tuesday 11 May 2010 4:27:01 pm David Winsemius wrote: > On May 11, 2010, at 1:45 PM, chen jia wrote: > > Hi there, > > > > I am looking for a function that takes a vector as input and generates > > all pair wise combination of the elements of the input vector. > > ?combn > > > For example, the input vector is c(1,2,3,4). The output vector is c(1 > > and 2, 1 and 3, 1 and 4, 2 and 3, 2 and 4, 3 and 4). > > That's not a vector.
True, although it is possible the OP wanted paste(combn(1:4, 2)[1,], "and", combn(1:4, 2)[2,]) -Ista > > > The > > representation here is generic. > > > > I can use a for loop to do it, but it gets slow when the number of > > elements of the input vector is large. > > > > Best, > > Jia > > David Winsemius, MD > West Hartford, CT > > ______________________________________________ > 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.