1) just because you don't use sqldf doesn't make it better. merge only does the join, not the conditions, so you have to apply them after merge. Untested (you should provide a complete example):
result <- merge ( detail, pdetail, by=TDATE, suffixes=c(".a",".b") ) result <- subset ( result, STIM.a >= STIM.b and STIM.a <=MAXTIM.b ) You can add a select argument to subset to remove the pdetail columns. 2) if is different than ifelse ... read the Introduction to R document, and/or read the help pages on if and ifelse. --------------------------------------------------------------------------- Jeff Newmiller The ..... ..... Go Live... DCN:<jdnew...@dcn.davis.ca.us> Basics: ##.#. ##.#. Live Go... Live: OO#.. Dead: OO#.. Playing Research Engineer (Solar/Batteries O.O#. #.O#. with /Software/Embedded Controllers) .OO#. .OO#. rocks...1k --------------------------------------------------------------------------- Sent from my phone. Please excuse my brevity. ramoss <ramine.mossad...@finra.org> wrote: >1)I am wandering how the following SQL statement can be written in R >language >w/o using sqldf: >create table detail2 as >select a.* >from detail a, > pdetail b >where a.TDATE=b.TDATE >and (a.STIM >= b.STIM and a.STIM <=b.MAXTIM) > >2) when try if then in R it only applies to the 1st row & not to whole >dataset like in SAS. How do you get round that? >in SAS: > >data summary; > set all1; > if entry='a:prop' then pctexec=stkful/stocks*100; >run; > > > >Thanks in advance for your help. > > > >-- >View this message in context: >http://r.789695.n4.nabble.com/Conditional-merging-in-R-if-then-statement-tp4641936.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. ______________________________________________ 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.