Try:
myStr <- "YD\\(001\\)"
In POSIX format, or in most such formats in fact, special characters
like parentheses have a particular meaning, and need to be escaped if
they are to have the "parenthesis" meaning. This is done typically by
putting a backslash in front of them. Since however a backslash has a
special meaning inside a "...", namely it is use to "escape" things,
we need to escape it, hence the two backslashes you see back to back.
You can use:
cat(myStr)
To see what hte string actually has in it.
A better way to solve your problem in your case is to use the
original myStr you had, but change the grep call to be:
grep(myStr, headers, fixed=TRUE)
The fixed=TRUE part tells it to treat myStr as a string to be matched
exactly. Of course ?grep should probably have led you to this.
Haris Skiadas
Department of Mathematics and Computer Science
Hanover College
On Aug 31, 2008, at 10:54 AM, Sébastien wrote:
Hi Jorge,
This is doing the work just fine. Thank you !
However, I would like to know what should be done with the grep
call...
just for my personal education :)
Sebastien
Jorge Ivan Velez a écrit :
Dear Sébastien,
Is this what you want?
which(myStr==headers)
[1] 2
which(headers%in%myStr)
[1] 2
HTH,
Jorge
On Sun, Aug 31, 2008 at 10:28 AM, Sébastien <[EMAIL PROTECTED]
<mailto:[EMAIL PROTECTED]>> wrote:
Dear R-users,
I need to dynamically recognize the index of a given string myStr
in a vector of string. The problem is that myStr might contain
parenthesis, causing grep not to recognize it the way I want (see
below). The help mentions that the pattern used by grep should be
in the POSIX format... I guess the problem is here;
unfortunately,
I am not familiar with the subtleties of the POSIX format
ex:
myStr <- "YD(001)"
headers <-c("TD", "YD(001)", "YD(002)", "T", "Y(001)", "Y(002)")
grep(myStr, headers)
How should I modify my grep call to get the match right?
Thank you for your help,
Sebastien
______________________________________________
R-help@r-project.org mailing list
https://stat.ethz.ch/mailman/listinfo/r-help
PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.
