Thanks Dennis. I will explore that. On Mon, Sep 27, 2010 at 7:45 AM, Dennis Murphy <djmu...@gmail.com> wrote: > Hi: > > One option is to read your data frame into R and then use your SQL code in > conjunction with the sqldf package. It uses SQLite as its engine. > > HTH, > Dennis > > > On Mon, Sep 27, 2010 at 4:29 AM, Xin Zhang <xin.zh...@gmail.com> wrote: >> >> Suppose I have the following data frame (df): >> >> Year Price >> ------------------- >> 2001 10 >> 2002 20 >> 2003 30 >> >> I would like to produce another data frame like this: >> >> a.Year a.Price b.Year b.Price >> ---------------------------------------------------- >> 2002 20 2001 10 >> 2003 30 2001 10 >> 2003 30 2002 20 >> >> In SQL, this can be done as >> >> select a.*, b.* >> from df as a, df as b >> where a.Year > b.Year >> >> How do I do this efficiently in R? >> >> Many thanks. >> >> ______________________________________________ >> 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. > >
______________________________________________ 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.
