Thanks Chuck I did not know about that MatchIt. I will check it out
Peter -----Original Message----- >From: Chuck Cleland <cclel...@optonline.net> >Sent: Dec 2, 2009 3:47 PM >To: Peter Flom <peterflomconsult...@mindspring.com> >Cc: r help <r-help@r-project.org> >Subject: Re: [R] Finding cases in one subset that are closet to another subset > >On 12/2/2009 3:01 PM, Peter Flom wrote: >> Good afternoon >> >> Running R2.10.0 on Windows >> >> I have a data frame that includes (among much else) a factor (In_2006) and a >> continuous variable (math_3_4). I would like to find the 2 cases for >> In_2006 = 0 that are closest to each case where In_2006 = 1. >> >> My data looks like >> >> In_2006 math_3_4 >> 0 55.1 >> 1 51.6 >> 1 18.1 >> 1 26.6 >> 1 14.1 >> 1 9.6 >> 1 48.9 >> 1 12.9 >> 0 63.0 >> 0 51.8 >> >> etc. for several hundred rows. >> >> I would like a new data frame that has all the cases where In_2006 = 1, and >> those cases of In_2006 that are closest to those cases > >Hi Peter: > > How about using one of the various matching packages (MatchIt, >optmatch, Matching)? For example, something like this: > > >DF <- data.frame(X = rbinom(200, 1, .1), Y = runif(200)) > >library(MatchIt) > >DF.match <- matchit(X ~ Y, data=DF, method='optimal', ratio=2) > >DF[c(rownames(DF.match$match.matrix), c(DF.match$match.matrix)),] > > >hope this helps, > >Chuck > >> Thanks in advance >> >> Peter >> >> Peter L. Flom, PhD >> Statistical Consultant >> Website: www DOT peterflomconsulting DOT com >> Writing; http://www.associatedcontent.com/user/582880/peter_flom.html >> Twitter: @peterflom >> >> ______________________________________________ >> 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. > >-- >Chuck Cleland, Ph.D. >NDRI, Inc. (www.ndri.org) >71 West 23rd Street, 8th floor >New York, NY 10010 >tel: (212) 845-4495 (Tu, Th) >tel: (732) 512-0171 (M, W, F) >fax: (917) 438-0894 Peter L. Flom, PhD Statistical Consultant Website: www DOT peterflomconsulting DOT com Writing; http://www.associatedcontent.com/user/582880/peter_flom.html Twitter: @peterflom ______________________________________________ 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.
