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.
