On Aug 31, 2012, at 10:11 AM, ramoss 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
You need to provide code that shows what you did. If you had the output of dat <- merge(a, b, by=TDATE) You could then limit your data depending on the names of the columns and whether MATIM was a duplicate name in "a" and "b" with something along the lines of subset(dat, STIM.x >= STIM.y & STIM.s <=MAXTIM.y) > it only applies to the 1st row Yes, that is how "if" is used in R. You need to educate yourself about R rather than assuming the similar words are necessarily the same function. read: ?"if" ?ifelse > & 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; > -- David Winsemius, MD Alameda, CA, USA ______________________________________________ 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.