Wolski wrote:
Hi!
For exact matches you can use
== or is.element.
To get the indices use which.
e.g. ==
x<-c("a","b","ab")
x=="a"
[1] TRUE FALSE FALSE
which((x=="a")==T)
Note, the "==T" part is superflously (same below).
In grep()'s regular expression, you can also use:
grep("^b$", nom)
or similar stuff.
Uwe Ligges
[1] 1
or
e.g. is.element
is.element(x,"a")
[1] TRUE FALSE FALSE
which(is.element(x,"a")==TRUE)
[1] 1
Sincerely
Eryk
*********** REPLY SEPARATOR ***********
On 7/8/2004 at 9:20 AM [EMAIL PROTECTED] wrote:
Let me present to you my problem :
I have a character vector x and I would like to obtain the indices of
the
elements of
this vector that yielded exactly a match.
For example, x=nom, pattern="b", I would to obtain 2 because "b" is on
the
second position.
First program :
nom <- c("a","b","ab")
grep("b",nom)
2 3
Then I try the option extended =FALSE (instead of TRUE by default) and I
obtain '2 3' a second time.
Please can you help me : How can I obtain only 2 in using the grep
function
(without using the match function).
Thanks you
Julie AUBERT
______________________________________________
[EMAIL PROTECTED] mailing list
https://www.stat.math.ethz.ch/mailman/listinfo/r-help
PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html
Dipl. bio-chem. Eryk Witold Wolski @ MPI-Moleculare Genetic
Ihnestrasse 63-73 14195 Berlin 'v'
tel: 0049-30-83875219 / \
mail: [EMAIL PROTECTED] ---W-W---- http://www.molgen.mpg.de/~wolski
______________________________________________
[EMAIL PROTECTED] mailing list
https://www.stat.math.ethz.ch/mailman/listinfo/r-help
PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html
______________________________________________
[EMAIL PROTECTED] mailing list
https://www.stat.math.ethz.ch/mailman/listinfo/r-help
PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html
