sqldf, authored by Gabor, if I read your intention correctly. D.
On Fri, Jan 22, 2010 at 5:00 PM, Don MacQueen <m...@llnl.gov> wrote: > Perhaps using the R merge() function, possibly twice in succession, will do > the job. (merge() does a one to many relational join, but with only two > dataframes at at time). > > Or, there is an R package that lets you use the SQL language on dataframes. > I don't recall its name, but a search on R packages should turn it up -- if > someone else doesn't provide the name sooner. > > -Don > > > At 10:52 AM -0800 1/22/10, GL wrote: > >> I need to merge three datasets and don't know how. If I were using SQL, I >> would use df3, look up the characteristics of each date in df1 and the >> value >> for each observation in df2. >> >> >> df1 - unique list of Dates and characteristics of those dates >> Date, YYYYMM, YYYYWW, DOW >> >> >> df2 - the raw data >> Date, Place, Value >> >> >> df3 - all posibile combinations of Date + Place (via >> expand.grid(unique(df2$Date),unique(df2$Place)) >> Date, Place >> >> I need to end up with: >> >> Date, YYYYMM, YYYYWW, DOW, PLace, Value (plug 0 if combo doesn't exist in >> raw data). >> >> Appreciate any help! >> >> >> -- >> View this message in context: http://* >> n4.nabble.com/Question-on-Merge-Lookup-tp1112384p1112384.html >> Sent from the R help mailing list archive at Nabble.com. >> >> ______________________________________________ >> 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. >> > > > -- > -------------------------------------- > Don MacQueen > Environmental Protection Department > Lawrence Livermore National Laboratory > Livermore, CA, USA > 925-423-1062 > > > ______________________________________________ > 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. > [[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.
