I have a list of IDs like this: AB1234 AB4567 AB8901
In my dataset, there are IDs like this: AB5555 AB7777 /// AB1234 AB4567 /// AB8901 /// AB6666 I used grep(list$ID, dataset$ID, value=T) It returned only one match, which was the very first match AB7777 /// AB1234. It seems once the first match was found, the matching procedure just stopped. Don MacQueen wrote: > > Perhaps > intersect() > or > merge() > will help. But, like others, I find it difficult to understand > exactly what you want. I'd suggest providing a short example with > actual ID values. > > -Don > > At 2:36 AM -0700 8/5/09, Rnewbie 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. > > > -- > -------------------------------------- > Don MacQueen > Environmental Protection Department > Lawrence Livermore National Laboratory > Livermore, CA, USA > 925-423-1062 > > ______________________________________________ > 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-tp24810298p24831677.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.
