Others have already pointed out %in% but regarding your comment about SQL, you can use SQL to manipulate R data frames using the sqldf package which provides an interface to lower level RSQLite (and RMySQL in the future) routines. The following examples use SQLite underneath:
DF <- data.frame(observation = c(1,2,3,4,5)) ID <- data.frame(ID = c(1, 3, 4)) library(sqldf) sqldf("select observation, observation in (select * from ID) `ID?` from DF") # or sqldf("select observation, observation in (1, 3, 4) `ID?` from DF") See home page at: http://sqldf.googlecode.com On 9/7/07, Takatsugu Kobayashi <[EMAIL PROTECTED]> wrote: > Hi RUsers, > > I am wonder if I can search observations whose IDs matches any of the > values in another vector, such as in MySQL. While I am learing MySQL for > future database management, I appreciate if anyone could give me a hint. > > Suppose I have one 5*1 vector containing observation IDs and > frequencies, and one 3*1 vector containing observation IDs. > > observation<-c(1,2,3,4,5) > ID<-c(1,3,4) > > Then, I would like to program a code that returns a results showing > matched observations like > > result: TRUE FALSE TRUE TRUE FALSE > > I am reading S programming, but I cannot find a way to do this. > > Thank you very much. > > Taka > > ______________________________________________ > 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.