[R] text matching

[Sarah Goslee]

Hi,

On Mon, Sep 19, 2011 at 6:15 AM, SNV Krishna <krishna at primps.com.sg> wrote:
> Hi All,
>
> I have a character vector by name tickers
>
>> head(tickers,10)
>
>            V1
> 1  ADARSHPL.BO
> 2        AGR.V
> 3          AGU
> 4       AGU.TO
> 5     AIMCO.BO
> 6  ALUFLUOR.BO
> 7        AMZ.V
> 8          AVD
> 9  ANILPROD.BO
> 10    ARIES.BO
>
> I would like to extract all elements that has ".BO" in it. I tried
>
>> grep("\.BO",tickers)
> Error: '\.' is an unrecognized escape in character string starting "\."

You need instead:
> tickers <- c("A.BO", "BOB", "C.BO")
> grep("\\.BO", tickers)
[1] 1 3
>
> tickers[grep("\\.BO", tickers)]
[1] "A.BO" "C.BO"


>> grep(".BO",tickers)
> [1] 1

That's odd; it should have returned many more matches. You may need to
check the format of your data.

> Could any one please guide me on this. Many thanks for the help
>
> Best Regards,
>
> Krishna
>


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