Prof Brian Ripley wrote:
On Mon, 19 Jan 2009, Rolf Turner wrote:
On 19/01/2009, at 10:44 AM, Gabor Grothendieck wrote:
Well, that's why it was only provided when you insisted. This is
not what regexp's are good at.
On Sun, Jan 18, 2009 at 4:35 PM, Rau, Roland r...@demogr.mpg.de wrote:
Wacek Kusnierczyk wrote:
attached are patches to character.c, names.c, and grep.R; if you tell me
forgot to add: the patches are against the latest r-devel
(19.01.2009). compiled and tested on 32b Ubuntu 8.04.
vQ
__
R-help@r-project.org
Rolf Turner wrote:
On 19/01/2009, at 10:44 AM, Gabor Grothendieck wrote:
Well, that's why it was only provided when you insisted. This is
not what regexp's are good at.
On Sun, Jan 18, 2009 at 4:35 PM, Rau, Roland r...@demogr.mpg.de wrote:
Thanks! (I have to admit, though, that I expected
Stavros Macrakis wrote:
On Sun, Jan 18, 2009 at 2:22 PM, Wacek Kusnierczyk
waclaw.marcin.kusnierc...@idi.ntnu.no wrote:
x[-grep(abc, x)]
which unfortunately fails if none of the strings in x matches the pattern,
i.e., grep returns integer(0);
Yes.
arguably, x[integer(0)]
On Mon, 19 Jan 2009, Rolf Turner wrote:
On 19/01/2009, at 10:44 AM, Gabor Grothendieck wrote:
Well, that's why it was only provided when you insisted. This is
not what regexp's are good at.
On Sun, Jan 18, 2009 at 4:35 PM, Rau, Roland r...@demogr.mpg.de wrote:
Thanks! (I have to admit,
Dear all,
let's assume I have a vector of character strings:
x - c(abcdef, defabc, qwerty)
What I would like to find is the following: all elements where the word
'abc' does not appear (i.e. 3 in this case of 'x').
Since I am not really experienced with regular expressions, I started
slowly
Just remove those elements that match:
x - c(abcdef, defabc, qwerty)
x[-grep('abc',x)]
[1] qwerty
On Sun, Jan 18, 2009 at 1:35 PM, Rau, Roland r...@demogr.mpg.de wrote:
Dear all,
let's assume I have a vector of character strings:
x - c(abcdef, defabc, qwerty)
What I would like to find
Rau, Roland wrote:
Dear all,
let's assume I have a vector of character strings:
x - c(abcdef, defabc, qwerty)
What I would like to find is the following: all elements where the word
'abc' does not appear (i.e. 3 in this case of 'x').
a quick shot is:
x[-grep(abc, x)]
which
Try this:
# indexes
setdiff(seq_along(x), grep(abc, x))
# values
setdiff(x, grep(abc, x, value = TRUE))
Another possibility is:
z - abc
x0 - c(x, z) # to handle no match case
x0[- grep(z, x0)] # values
On Sun, Jan 18, 2009 at 1:35 PM, Rau, Roland r...@demogr.mpg.de wrote:
Dear all,
Roland,
I think you were almost there with your first example. Howabout using:
x - c(abcdef, defabc, qwerty)
y - grep(pattern=abc, x=x)
z.char - x[-y]
z.index - (1:length(x))[-y]
z.char
[1] qwerty
z.index
[1] 3
Cheers,
eric
Rau, Roland wrote:
Dear all,
let's assume I have a vector
Jorge Ivan Velez wrote:
Hi Wacek,
I think you wanted to say strings instead x in your last line : )
of course, thanks. the correct version is:
if(length(matching - grep(pattern, strings)))
strings[-matching]
else strings
btw., and in relation to a recent post complaining about
[mailto:ggrothendi...@gmail.com]
Sent: Sun 1/18/2009 8:28 PM
To: Rau, Roland
Cc: r-help@r-project.org
Subject: Re: [R] regex - negate a word
Try this:
# indexes
setdiff(seq_along(x), grep(abc, x))
# values
setdiff(x, grep(abc, x, value = TRUE))
Another possibility is:
z - abc
x0 - c(x, z
if there is really no regular expression which does the job?!?
Thanks again,
Roland
-Original Message-
From: Gabor Grothendieck [mailto:ggrothendi...@gmail.com]
Sent: Sun 1/18/2009 8:28 PM
To: Rau, Roland
Cc: r-help@r-project.org
Subject: Re: [R] regex - negate a word
Try
Gabor Grothendieck wrote:
Try this:
# values
setdiff(x, grep(abc, x, value = TRUE))
Another possibility is:
z - abc
x0 - c(x, z) # to handle no match case
x0[- grep(z, x0)] # values
on quick testing, these two and the if-based version have comparable
runtime, with a minor win for
In that case just add fixed = TRUE
On Sun, Jan 18, 2009 at 2:58 PM, Wacek Kusnierczyk
waclaw.marcin.kusnierc...@idi.ntnu.no wrote:
Gabor Grothendieck wrote:
Try this:
# values
setdiff(x, grep(abc, x, value = TRUE))
Another possibility is:
z - abc
x0 - c(x, z) # to handle no match case
Gabor Grothendieck wrote:
In that case just add fixed = TRUE
in general, if you want a complex pattern, you don't use 'fixed', and
then again you risk incorrect (well, correct for r, but not for the
problem) result in case no input string matches the pattern.
vQ
Gabor Grothendieck wrote:
Try this:
grep(^([^a]|a[^b]|ab[^c])*.{0,2}$, x, perl = TRUE)
... and see how cumbersome it becomes for a pattern as trivial as 'abc'.
in perl, you typically don't invent such negative patterns, but rather
don't match positive patterns: instead of the match
Wacek Kusnierczyk wrote:
On Sun, Jan 18, 2009 at 2:37 PM, Rau, Roland r...@demogr.mpg.de wrote:
Thank you very much to all of you for your fast and excellent help.
Since the -grep(...) solution seems to be favored by most of the answers,
I just wonder if there is really no regular
Wacek Kusnierczyk wrote:
# r code
ungrep = function(pattern, x, ...)
grep(paste(pattern, (*COMMIT)(*FAIL)|(*ACCEPT), sep=), x,
perl=TRUE, ...)
strings = c(abc, xyz)
pattern = a[a-z]
(filtered = strings[ungrep(pattern, strings)])
# xyz
this was a toy example, but if you need this
Thanks! (I have to admit, though, that I expected something simple)
Thanks,
Roland
-Original Message-
From: Gabor Grothendieck [mailto:ggrothendi...@gmail.com]
Sent: Sun 1/18/2009 8:54 PM
To: Rau, Roland
Cc: r-help@r-project.org
Subject: Re: [R] regex - negate a word
Try this:
grep
: Gabor Grothendieck [mailto:ggrothendi...@gmail.com]
Sent: Sun 1/18/2009 8:54 PM
To: Rau, Roland
Cc: r-help@r-project.org
Subject: Re: [R] regex - negate a word
Try this:
grep(^([^a]|a[^b]|ab[^c])*.{0,2}$, x, perl = TRUE)
On Sun, Jan 18, 2009 at 2:37 PM, Rau, Roland r...@demogr.mpg.de wrote
On 19/01/2009, at 10:44 AM, Gabor Grothendieck wrote:
Well, that's why it was only provided when you insisted. This is
not what regexp's are good at.
On Sun, Jan 18, 2009 at 4:35 PM, Rau, Roland r...@demogr.mpg.de
wrote:
Thanks! (I have to admit, though, that I expected something simple)
That's an entirely different point from whether regular expressions
can do it as grep -v is just another way to do it without using a regular
expression to specify the entire job.
On Sun, Jan 18, 2009 at 5:02 PM, Rolf Turner r.tur...@auckland.ac.nz wrote:
On 19/01/2009, at 10:44 AM, Gabor
On Sun, Jan 18, 2009 at 2:22 PM, Wacek Kusnierczyk
waclaw.marcin.kusnierc...@idi.ntnu.no wrote:
x - c(abcdef, defabc, qwerty)
...[find] all elements where the word 'abc' does not appear (i.e. 3 in this
case of 'x').
x[-grep(abc, x)]
which unfortunately fails if none of the strings in x
Note that the variation of this that I posted already handles that case.
On Sun, Jan 18, 2009 at 5:32 PM, Stavros Macrakis macra...@alum.mit.edu wrote:
On Sun, Jan 18, 2009 at 2:22 PM, Wacek Kusnierczyk
waclaw.marcin.kusnierc...@idi.ntnu.no wrote:
x - c(abcdef, defabc, qwerty)
...[find] all
25 matches
Mail list logo
