Although this is probably not directly applicable to this problem I might mention here that merge.zoo does support left and right joins and that handles problems similar to this. z3t, z3ft, z3tf and z3f below have times of both unioned, the times of z2, the times of z1 and the times of both z1 and z2 intersected respectively:
library(zoo) z1 <- zoo(1:5, 1:5) z2 <- zoo(2:6, 2:6) z3t <- merge(z1, z2, all = TRUE) z3ft <- merge(z1, z2, all = c(FALSE, TRUE)) z3tf <- merge(z1, z2, all = c(TRUE, FALSE)) z3f - merge(z1, z2, all = FALSE) On 07 Aug 2006 22:14:05 +0200, Peter Dalgaard <[EMAIL PROTECTED]> wrote: > "Mark Na" <[EMAIL PROTECTED]> writes: > > > Dear R community, > > > > I have two dataframes "first" and "second" which share a unique identifier. > > > > I wish to make a new dataframe "third" retaining only the rows in > > "first" which also occur in "second". > > > > I have tried using merge but can't seem to figure it out. Any ideas? > > Doesn't sound like a merge problem. Will this do it?: > > first[first$ID %in% second$ID,] > > -- > O__ ---- Peter Dalgaard Øster Farimagsgade 5, Entr.B > c/ /'_ --- Dept. of Biostatistics PO Box 2099, 1014 Cph. K > (*) \(*) -- University of Copenhagen Denmark Ph: (+45) 35327918 > ~~~~~~~~~~ - ([EMAIL PROTECTED]) FAX: (+45) 35327907 > > ______________________________________________ > R-help@stat.math.ethz.ch 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@stat.math.ethz.ch 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.
