Hi, On Wed, May 4, 2011 at 10:32 AM, Roccato Alfredo (UniCredit) <alfredo.rocc...@unicredit.eu> wrote: > I'd to match-merge 2 tables in such a manner that I keep all the rows in > table 1, but not the rows that are in both table 1 and 2. > Thank you for your help, > Alfredo > >> master <- data.frame(ID=2001:2011) >> train <- data.frame(ID=2004:2006) >> valid <- ??? > > in this example table valid should have the following > >> str(valid) > Year: int 2001 2002 2003 2007 2008 2009 2010 2011
Are you working with only one column at a time? If so: R> keep <- !(master$ID %in% train$ID) R> valid <- master[keep,] If you are working with combinations of columns as the keys for each row, there are other ways ... > in SAS I'd do the following: > data master; do id=2001 to 2011; output; end; run; > data train; do id=2004 to 2006; output; end; run; > data valid; merge master(in=a) train(in=b); by id; if a and not b; run; > > and in SQL: > create table valid as > select a.* from master where ID not in (select ID from train) My solution does pretty much what this select statement would do. -steve -- Steve Lianoglou Graduate Student: Computational Systems Biology | Memorial Sloan-Kettering Cancer Center | Weill Medical College of Cornell University Contact Info: http://cbio.mskcc.org/~lianos/contact ______________________________________________ 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.
