[R] join tables in R

[Petr Savicky]

On Wed, May 04, 2011 at 04:32:14PM +0200, Roccato Alfredo (UniCredit) 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

Hi.

Try the following, which assumes that "train" is a subset of "master".

  master <- data.frame(ID=2001:2011)
  train  <- data.frame(ID=2004:2006)
  valid <- master[! (master[, 1] %in% train[ ,1]), , drop=FALSE]

Hope this helps.

Petr Savicky.