How to compare characters vectors for partial matches in R

Question

This must be a simple question, but as an R newcomer I haven't been able to figure it out.

I have two character vectors, List1 and List2, and I would like to know how many of the samples in List1 are also found in List2. But List2 often has multiple names put together which seems to be messing things up. Here are the hypothetical lists:

List1 <- c("SampleX", "SampleY", "SampleZ", "SampleQ")

List2 <- c("SampleX", "SampleY", "Alias1,Alias2,SampleZ")

I can get an output that identifies SampleX and SampleY, but not SampleZ.

Any suggestions??

Thanks!!

Answer 1

How about:

List1[sapply(List1,function(x) any(grepl(x,List2)))]
[1] "SampleX" "SampleY" "SampleZ"

?