You could use findInterval() along with a trick with c(rbind(...)): > i <- findInterval(x=df.1$time, vec=c(rbind(df.2$from, df.2$to))) > i [1] 1 1 1 2 3 3 3 5 5 6
The even-valued outputs would map to NA's, the odds to value[(i+1)/2], but you can use the c(rbind(...)) trick again: > c(rbind(df.2$value, NA))[i] [1] 1 1 1 NA 3 3 3 5 5 NA Bill Dunlap Spotfire, TIBCO Software wdunlap tibco.com > -----Original Message----- > From: r-help-boun...@r-project.org > [mailto:r-help-boun...@r-project.org] On Behalf Of René Mayer > Sent: Saturday, May 14, 2011 11:06 AM > To: David Winsemius > Cc: r-help@r-project.org > Subject: Re: [R] how to merge within range? > > thanks David and Ian, > let me make a better example as the first one was flawed > > df.1=data.frame(round((1:10)*100+rnorm(10)), value=NA) > names(df.1) = c("time", "value") > df.1 > time value > 1 101 NA > 2 199 NA > 3 301 NA > 4 401 NA > 5 501 NA > 6 601 NA > 7 700 NA > 8 800 NA > 9 900 NA > 10 1000 NA > > # from and to define ranges within time, > # note that from and to may not match the numbers given in time > df.2=data.frame(from=c(99,500,799),to=c(303,702,950), value=c(1,3,5)) > df.2 > from to value > 1 99 303 1 > 2 500 702 3 > 3 799 950 5 > > what I want is: > time value > 1 101 1 > 2 199 1 > 3 301 1 > 4 401 NA > 5 501 3 > 6 601 3 > 7 700 3 > 8 800 5 > 9 900 5 > 10 1000 NA > > @David I don't know what you mean by 2 merges, > René > > > > > > Zitat von "David Winsemius" <dwinsem...@comcast.net>: > > > > > On May 14, 2011, at 9:16 AM, Ian Gow wrote: > > > >> If I assume that the third column in data.frame.2 is named > "val" then in > >> SQL terms it _seems_ you want > >> > >> SELECT a.time, b.val FROM data.frame.1 AS a LEFT JOIN > data.frame.2 AS b ON > >> a.time BETWEEN b.start AND b.end; > >> > >> Not sure how to do that elegantly using R subsetting/merge, > > > > Huh? It's just two merge()'s (... once you fix the error in > the example.) > > > > -- > > David > > > >> but you might > >> try a package that allows you to use SQL, such as sqldf. > >> > >> > >> On 5/14/11 8:03 AM, "David Winsemius" > <dwinsem...@comcast.net> wrote: > >> > >>> > >>> On May 14, 2011, at 8:12 AM, René Mayer wrote: > >>> > >>>> Hello, > >>>> how can one merge > >>> > >>> And what happened when you typed: > >>> > >>> ?merge > >>> > >>>> two data frames when in the second data frame one column > defines the > >>>> start values > >>>> and another defines the end value of the to be merged range. > >>>> data.frame.1 > >>>> time ... > >>>> 13 > >>>> 24 > >>>> 35 > >>>> 46 > >>>> 55 > >>>> ... > >>>> data.frame.2 > >>>> start end > >>>> 24 37 ?h? ? > >>>> ... > >>>> > >>>> should result in this > >>>> 13 NA > >>>> 24 ?h? > >>>> 35 ?h? > >>>> 46 NA > >>>> 55 > >>>> ? > >>> > >>> And _why_ would that be? > >>> > >>> > >>>> thanks, > >>>> René > >>>> > >>>> ______________________________________________ > >>>> 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. > >>> > >>> David Winsemius, MD > >>> West Hartford, CT > >>> > >>> ______________________________________________ > >>> 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. > >> > >> > > > > David Winsemius, MD > > West Hartford, CT > > > > > > ______________________________________________ > 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.
