Hi, I'm looking for a function that will take a list of columns or data.frame and corvert it to cartesian pairlist. For example for this data.frame (see below), I'd like to get a list of all possible pairs:> soundcs rs ns 7 5 2 4 5 4 6 3 1 8 4 1 6 4 2 6 7 1 2 2 5 9 2 5 how can I get this?> mylist((cs,rs), (cs,ns), (rs,ns)) This list contains a set of all possible combinations of column pairs. Thank you for your help. -- View this message in context: http://old.nabble.com/How-to-make-a-cartesian-pairlist-from-a-vector--tp26452861p26452861.html Sent from the R help mailing list archive at Nabble.com.
Charles C. Berry
2009-Nov-21 02:06 UTC
[R] How to make a cartesian pairlist from a vector?
On Fri, 20 Nov 2009, newbyr wrote:> > Hi, > > I'm looking for a function that will take a list of columns or data.frame > and corvert it to cartesian pairlist. For example for this data.frame (see > below), I'd like to get a list of all possible pairs: > >> sound > cs rs ns > 7 5 2 > 4 5 4 > 6 3 1 > 8 4 1 > 6 4 2 > 6 7 1 > 2 2 5 > 9 2 5 >> how can I get this? >> mylist > ((cs,rs), (cs,ns), (rs,ns))str(combn(colnames(df),2,function(x) df[,x],simplify=F)) see ?combn HTH, Chuck p.s. Following the posting guide's hints you might try ?combinations # no go, but it says try ??combinations ??combinations # shows utils:combn ?combn # bingo!> > This list contains a set of all possible combinations of column pairs. > > Thank you for your help. > > -- > View this message in context: http://old.nabble.com/How-to-make-a-cartesian-pairlist-from-a-vector--tp26452861p26452861.html > Sent from the R help mailing list archive at Nabble.com. > > ______________________________________________ > R-help at 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. >Charles C. Berry (858) 534-2098 Dept of Family/Preventive Medicine E mailto:cberry at tajo.ucsd.edu UC San Diego http://famprevmed.ucsd.edu/faculty/cberry/ La Jolla, San Diego 92093-0901