[R] Search list of elements for a specific pattern

Sarah Goslee sarah.goslee at gmail.com
Fri Jun 22 18:22:37 CEST 2012


You should use grepl() instead:

 Alu<-mutList[grepl("Alu",mutList)]

or some variant of the above, depending on the actual structure of
mutList (which might be a data frame, but doesn't appear to be a
generic list). str() and dput() are both very useful for asking
well-formed questions.

Sarah

On Fri, Jun 22, 2012 at 12:14 PM, Joshua Budman <josh.budman at gmail.com> wrote:
> Hi,
> I have a list of mutations, called "mutList", of the form:
>
>  > head(mutList)
>            Alu
> 1         AluJ
> 2  AluJ/F(R)AM
> 3    AluJ/FLAM
> 4    AluJ/FRAM
> 5 AluJ/monomer
> 6        AluJb
>
> It contains about 500 elements and not all of them contain the
> sequence "Alu". I tried using this code:
> Alu<-mutList[which(grep("Alu",mutList)==1)]
>
> But that simply returned all of them elements in the list. Is there a
> way to modify the list such that I have only the elements containing
> "Alu" in the new list? Help would be appreciated!
>
> Josh
>
>

-- 
Sarah Goslee
http://www.functionaldiversity.org



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