I think you want to use either 'match' or '%in%' x <- dataframe$ID %in% list$ID # TRUE if it is in list
On Wed, Aug 5, 2009 at 5:36 AM, Rnewbie<xua...@yahoo.com> wrote: > > I wanted to extract my interested rows from a dataframe. I used: > > grep(list$ID, dataframe$ID, value=T) #list contains a list of my interested > IDs > > I got one match in return, which is the very first ID in list. It seems the > matching process just stopped, once the first match was found. > > > > David Winsemius wrote: >> >> >> On Aug 4, 2009, at 11:16 AM, Rnewbie wrote: >> >>> >>> dear all, >>> >>> I got a problem with pattern matching using grep. I extracted a list >>> of >>> characters from a data frame, and I tried to match this list of >>> characters >>> to a column from another data frame. In return, I got only one >>> match, but >>> there should be far more matches. Any ideas what has gone wrong? >> >> In general this falls into the category of a request to "read my >> mind". One, out of probably an infinite number, of ways to get such a >> result is to use if() when you needed ifelse(). >> >>> >>> Another question, if I also want to match the whole of the elements >>> against >>> the non-initial parts of the elements in another table. Which >>> command should >>> I use? >> >> Cannot even assign a semantic meaning to that one. What is are "non- >> initial parts of the elements of another table"? >> >> >> ****************************************************************** >>> .... provide commented, minimal, self-contained, reproducible code. >> ****************************************************************** >>> >>> Thanks >> >> David Winsemius, MD >> Heritage Laboratories >> 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. >> >> > > -- > View this message in context: > http://www.nabble.com/problem-with-pattern-matching-tp24810298p24823683.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. > -- Jim Holtman Cincinnati, OH +1 513 646 9390 What is the problem that you are trying to solve? ______________________________________________ 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.
