[R] grep and strings

[K Fung]

Thanks

Your suggestion works.  The fix is to use double \\
rather than single \.  Changing this makes grep work
as well.


--- Spencer Graves <spencer.graves at pdf.com> wrote:
> How about the following: 
> 
>  > tst <- c(".a.", "asdf")
>  > sum(regexpr("\\.a\\.", tst)>0)
> [1] 1
> 
>       hope this helps.  spencer graves
> 
> K Fung wrote:
> 
> >I have the following command:
> >
> >length(
> >  grep("\.a\.", names(temp)))
> >
> >where temp is a vector with names
> >
> >I want to count the number of entries that contain
> the
> >sequence of characters ".a.".  However, R seems to
> >return all entries that contain "a" (every entry
> >contains "." in this example).
> >
> >How should I fix this?  Thanks
> >
> >
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