Have you tried 'pasting' the values together and then using this as the key for the join?
On Sun, Sep 12, 2010 at 2:39 PM, Anyi Zhu <anyi....@gmail.com> wrote: > Hi all, > > I am just wondering if there is a more efficient way of merging two large > datasets based on the values of multiple columns, some of which are not > numerical. > > The default merge function in dataframe is very inefficient and the merge > function in data.table seems to be faster, but it does not seem to allow > keys that are not numerical in nature. > > Any other suggestion? > > Thanks a lot! > > [[alternative HTML version deleted]] > > ______________________________________________ > 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. > -- Jim Holtman Cincinnati, OH +1 513 646 9390 What is the problem that you are trying to solve? ______________________________________________ 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.