R help - Feb 2009 - using perl regular expression

Hello everybody!

I'm using Perl regular Expression for find pattern in my data set.

The pattern is: NaQxy, where a=E, F, G or H and xy != 29. I have tried this:

pattern <- "^N[E-H]Q[0-9]{2,2}"
index <- grep(pattern, X, perl=T)   #where X is my vector

But the problem is the xy should not be 29. How can I solve this problem.

Thanks!!!



Regards,

Katrine



	[[alternative HTML version deleted]]

Katrine Damgaard wrote:
> Hello everybody!
>
> I'm using Perl regular Expression for find pattern in my data set.
>
> The pattern is: NaQxy, where a=E, F, G or H and xy != 29. I have tried
this:
>
> pattern <- "^N[E-H]Q[0-9]{2,2}"
> index <- grep(pattern, X, perl=T)   #where X is my vector
>
> But the problem is the xy should not be 29. How can I solve this problem.
>
>   
pattern = '^N[E-H]Q(?!29)[0-9]{2}'
index = grep(pattern, X, perl=TRUE)

note, an input like NaQ290 will *not* match;  you may need to further
specify the pattern.

vQ

Do it in two steps:
> x <- c("NEQ23", "NHQ29", "NGQ00",
"NFQ123")
> pat <- "N[E-H]Q[0-9]{2}"
> bad <- "N[E-H]Q29"
> all <- grep(pat, x, perl=TRUE)
> x29 <- grep(bad, x, perl=TRUE)
> setdiff(all, x29)
[1] 1 3 4
>

On Tue, Feb 24, 2009 at 7:57 AM, Katrine Damgaard
<Katrine.Damgaard at kunnskapssenteret.no> wrote:
> Hello everybody!
>
> I'm using Perl regular Expression for find pattern in my data set.
>
> The pattern is: NaQxy, where a=E, F, G or H and xy != 29. I have tried
this:
>
> pattern <- "^N[E-H]Q[0-9]{2,2}"
> index <- grep(pattern, X, perl=T) ? #where X is my vector
>
> But the problem is the xy should not be 29. How can I solve this problem.
>
> Thanks!!!
>
>
>
> Regards,
>
> Katrine
>
>
>
> ? ? ? ?[[alternative HTML version deleted]]
>
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>


-- 
Jim Holtman
Cincinnati, OH
+1 513 646 9390

What is the problem that you are trying to solve?