Matching regular expressions Dear useRs!
I have the following problem. I would like to find objects in my environment that have two strings in it. For example, I might want to find objects that have in their names "MY" and "TARGET". I do not care about the ordering of these two substrings in the name, neither what is in front, behind or between them, the only thing important is that both words are present. I apologize if this is covered in help pages (then I did not understand it by reading them several times) or it was answered previously (then I did not find it). Since "ls" with argument pattern essentially uses "grep" (if I am not mistaken), I have an example for "grep" text<-c("somethigMYsomthing elseTARGET another thing","MY somthing TARGET another thing","somethig somthing elseTARGETMY another thing","somethigMTARGETY another thing") grep(pattern="MY&TARGET", x=text) #I would like to get 1 2 3 and not 4 or actually their names using text[grep(pattern="MY&TARGET", x=text)] #of course, the "pattern" in this case is wrong I know I can do text[grep(pattern="MY", x=text)][grep(pattern="TARGET", x=text[grep(pattern="MY",x=text)])] However I hope there exists a more elegant way. Thanks in advance for any suggestions! Best, Ales Ziberna ______________________________________________ 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