You can use setdiff if you only need the unique values of a that are not in b. If you want all values you can use
a[a%in%setdiff(a,b)] There are also intersection, union etc... see ?setdiff On Thu, 11 Nov 2004, Alexander Sokol wrote: > Hello, > > I have the following very simple problem: > > Say I have two vectors, > > a<-c(1,7,4,5,9,11) > b<-c(7,4,9) > > I would like to create a vector containing the elements in a which are not in > b. > > Obviously, this is possible by writing > > a[a!=b[1] & a!=b[2] & a!=b[3]] > > But I would like a solution which is applicable to the situation where the > number of elements in b is unknown. > > I have looked in the R manuals, the FAQ and the mailing lists, but have been > unable to find a solution. > > Thank you for your replies, > Alexander > > ______________________________________________ > [EMAIL PROTECTED] mailing list > https://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html > ______________________________________________ [EMAIL PROTECTED] mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html
