Re: [R] extracting a matched string using regexpr
Here are two ways to extract 5 digits.
In the first one \\1 refers to the portion matched between the
parentheses in the regular expression.
In the second one strapply is like apply where the object to be worked
on is the first argument (array for apply, string for strapply) the
second modifies it (which dimension for apply, regular expression for
strapply) and the last is a function which acts on each value
(typically each row or column for apply and each match for strapply).
In this case we use c as our function to just return all the results.
They are returned in a list with one component per string but here
test is just a single string so we get a list one long and we ask for
the contents of the first component using [[1]].
# 1 - sub
sub(.*(\\d{5}).*, \\1, test)
# 2 - strapply - see http://gsubfn.googlecode.com
library(gsubfn)
strapply(test, \\d{5}, c)[[1]]
On Wed, May 5, 2010 at 5:13 PM, steven mosher mosherste...@gmail.com wrote:
Given a text like
I want to be able to extract a matched regular expression from a piece of
text.
this apparently works, but is pretty ugly
# some html
test-/trtrth88958/ththAbcdsef/thth67.8S/thth68.9\nW/thth26m/th
# a pattern to extract 5 digits
pattern-[0-9]{5}
# regexpr returns a start point[1] and an attribute match.length
attr(,match.length)
# get the substring from the start point to the stop point.. where stop =
start +length-1
answer-substr(test,regexpr(pattern,test)[1],regexpr(pattern,test)[1]+attr(regexpr(pattern,test),match.length)-1)
answer
[1] 88958
I tried using sub(pattern, replacement, x ) with a regexp that captured the
group. I'd found an example of this in the mails
but it didnt seem to work..
__
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.
Re: [R] extracting a matched string using regexpr
Thanks I was looking at that package and reading your mails in the archive.
I think my tiny mind got twisted in the regexp..
On Wed, May 5, 2010 at 2:35 PM, Gabor Grothendieck
ggrothendi...@gmail.comwrote:
Here are two ways to extract 5 digits.
In the first one \\1 refers to the portion matched between the
parentheses in the regular expression.
In the second one strapply is like apply where the object to be worked
on is the first argument (array for apply, string for strapply) the
second modifies it (which dimension for apply, regular expression for
strapply) and the last is a function which acts on each value
(typically each row or column for apply and each match for strapply).
In this case we use c as our function to just return all the results.
They are returned in a list with one component per string but here
test is just a single string so we get a list one long and we ask for
the contents of the first component using [[1]].
# 1 - sub
sub(.*(\\d{5}).*, \\1, test)
# 2 - strapply - see http://gsubfn.googlecode.com
library(gsubfn)
strapply(test, \\d{5}, c)[[1]]
On Wed, May 5, 2010 at 5:13 PM, steven mosher mosherste...@gmail.com
wrote:
Given a text like
I want to be able to extract a matched regular expression from a piece of
text.
this apparently works, but is pretty ugly
# some html
test-/trtrth88958/ththAbcdsef/thth67.8S/thth68.9\nW/thth26m/th
# a pattern to extract 5 digits
pattern-[0-9]{5}
# regexpr returns a start point[1] and an attribute match.length
attr(,match.length)
# get the substring from the start point to the stop point.. where stop =
start +length-1
answer-substr(test,regexpr(pattern,test)[1],regexpr(pattern,test)[1]+attr(regexpr(pattern,test),match.length)-1)
answer
[1] 88958
I tried using sub(pattern, replacement, x ) with a regexp that captured
the
group. I'd found an example of this in the mails
but it didnt seem to work..
[[alternative HTML version deleted]]
__
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.
Re: [R] extracting a matched string using regexpr
test
[1]
/trtrth88958/ththAbcdsef/thth67.8S/thth68.9\nW/thth26m/th
sub(.*(\\d{5}).*, \\1, test)
[1] /th
sub(.*([0-9]{5}).*,\\1,test)
[1] 88958
I think the / in the source throws something off.
as the group capture appears to not be working, except the bracket version
it did.
On Wed, May 5, 2010 at 2:35 PM, Gabor Grothendieck
ggrothendi...@gmail.comwrote:
Here are two ways to extract 5 digits.
In the first one \\1 refers to the portion matched between the
parentheses in the regular expression.
In the second one strapply is like apply where the object to be worked
on is the first argument (array for apply, string for strapply) the
second modifies it (which dimension for apply, regular expression for
strapply) and the last is a function which acts on each value
(typically each row or column for apply and each match for strapply).
In this case we use c as our function to just return all the results.
They are returned in a list with one component per string but here
test is just a single string so we get a list one long and we ask for
the contents of the first component using [[1]].
# 1 - sub
sub(.*(\\d{5}).*, \\1, test)
# 2 - strapply - see http://gsubfn.googlecode.com
library(gsubfn)
strapply(test, \\d{5}, c)[[1]]
On Wed, May 5, 2010 at 5:13 PM, steven mosher mosherste...@gmail.com
wrote:
Given a text like
I want to be able to extract a matched regular expression from a piece of
text.
this apparently works, but is pretty ugly
# some html
test-/trtrth88958/ththAbcdsef/thth67.8S/thth68.9\nW/thth26m/th
# a pattern to extract 5 digits
pattern-[0-9]{5}
# regexpr returns a start point[1] and an attribute match.length
attr(,match.length)
# get the substring from the start point to the stop point.. where stop =
start +length-1
answer-substr(test,regexpr(pattern,test)[1],regexpr(pattern,test)[1]+attr(regexpr(pattern,test),match.length)-1)
answer
[1] 88958
I tried using sub(pattern, replacement, x ) with a regexp that captured
the
group. I'd found an example of this in the mails
but it didnt seem to work..
[[alternative HTML version deleted]]
__
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.
Re: [R] extracting a matched string using regexpr
That's not what I get:
test-/trtrth88958/ththAbcdsef/thth67.8S/thth68.9\nW/thth26m/th
sub(.*(\\d{5}).*, \\1, test)
[1] 88958
R.version.string
[1] R version 2.10.1 (2009-12-14)
I also got the above in R 2.11.0 patched as well.
On Wed, May 5, 2010 at 5:55 PM, steven mosher mosherste...@gmail.com wrote:
test
[1]
/trtrth88958/ththAbcdsef/thth67.8S/thth68.9\nW/thth26m/th
sub(.*(\\d{5}).*, \\1, test)
[1] /th
sub(.*([0-9]{5}).*,\\1,test)
[1] 88958
I think the / in the source throws something off.
as the group capture appears to not be working, except the bracket version
it did.
On Wed, May 5, 2010 at 2:35 PM, Gabor Grothendieck ggrothendi...@gmail.com
wrote:
Here are two ways to extract 5 digits.
In the first one \\1 refers to the portion matched between the
parentheses in the regular expression.
In the second one strapply is like apply where the object to be worked
on is the first argument (array for apply, string for strapply) the
second modifies it (which dimension for apply, regular expression for
strapply) and the last is a function which acts on each value
(typically each row or column for apply and each match for strapply).
In this case we use c as our function to just return all the results.
They are returned in a list with one component per string but here
test is just a single string so we get a list one long and we ask for
the contents of the first component using [[1]].
# 1 - sub
sub(.*(\\d{5}).*, \\1, test)
# 2 - strapply - see http://gsubfn.googlecode.com
library(gsubfn)
strapply(test, \\d{5}, c)[[1]]
On Wed, May 5, 2010 at 5:13 PM, steven mosher mosherste...@gmail.com
wrote:
Given a text like
I want to be able to extract a matched regular expression from a piece
of
text.
this apparently works, but is pretty ugly
# some html
test-/trtrth88958/ththAbcdsef/thth67.8S/thth68.9\nW/thth26m/th
# a pattern to extract 5 digits
pattern-[0-9]{5}
# regexpr returns a start point[1] and an attribute match.length
attr(,match.length)
# get the substring from the start point to the stop point.. where stop
=
start +length-1
answer-substr(test,regexpr(pattern,test)[1],regexpr(pattern,test)[1]+attr(regexpr(pattern,test),match.length)-1)
answer
[1] 88958
I tried using sub(pattern, replacement, x ) with a regexp that captured
the
group. I'd found an example of this in the mails
but it didnt seem to work..
__
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.
Re: [R] extracting a matched string using regexpr
On May 5, 2010, at 5:35 PM, Gabor Grothendieck wrote:
Here are two ways to extract 5 digits.
In the first one \\1 refers to the portion matched between the
parentheses in the regular expression.
In the second one strapply is like apply where the object to be worked
on is the first argument (array for apply, string for strapply) the
second modifies it (which dimension for apply, regular expression for
strapply) and the last is a function which acts on each value
(typically each row or column for apply and each match for strapply).
In this case we use c as our function to just return all the results.
They are returned in a list with one component per string but here
test is just a single string so we get a list one long and we ask for
the contents of the first component using [[1]].
# 1 - sub
sub(.*(\\d{5}).*, \\1, test)
test
[1] /trtrth88958/ththAbcdsef/thth67.8S/thth68.9\nW/
thth26m/th
I get different results than I expected given that \\d should be
synonymous with [0-9]:
sub(.*([0-9]{5}).*, \\1, test)
[1] 88958
sub(.*(\\d{5}).*, \\1, test)
[1] /th
--
David.
# 2 - strapply - see http://gsubfn.googlecode.com
library(gsubfn)
strapply(test, \\d{5}, c)[[1]]
On Wed, May 5, 2010 at 5:13 PM, steven mosher
mosherste...@gmail.com wrote:
Given a text like
I want to be able to extract a matched regular expression from a
piece of
text.
this apparently works, but is pretty ugly
# some html
test-/trtrth88958/ththAbcdsef/thth67.8S/
thth68.9\nW/thth26m/th
# a pattern to extract 5 digits
pattern-[0-9]{5}
# regexpr returns a start point[1] and an attribute match.length
attr(,match.length)
# get the substring from the start point to the stop point.. where
stop =
start +length-1
answer-substr(test,regexpr(pattern,test)[1],regexpr(pattern,test)
[1]+attr(regexpr(pattern,test),match.length)-1)
answer
[1] 88958
I tried using sub(pattern, replacement, x ) with a regexp that
captured the
group. I'd found an example of this in the mails
but it didnt seem to work..
__
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.
David Winsemius, MD
West Hartford, CT
__
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.
Re: [R] extracting a matched string using regexpr
Hmm.
I have R11 just downloaded fresh.
I'll reload a new session..and revert. I will note that I've had trouble
with \\d
which is why I was using [0-9]
MAC here.
On Wed, May 5, 2010 at 3:00 PM, Gabor Grothendieck
ggrothendi...@gmail.comwrote:
That's not what I get:
test-/trtrth88958/ththAbcdsef/thth67.8S/thth68.9\nW/thth26m/th
sub(.*(\\d{5}).*, \\1, test)
[1] 88958
R.version.string
[1] R version 2.10.1 (2009-12-14)
I also got the above in R 2.11.0 patched as well.
On Wed, May 5, 2010 at 5:55 PM, steven mosher mosherste...@gmail.com
wrote:
test
[1]
/trtrth88958/ththAbcdsef/thth67.8S/thth68.9\nW/thth26m/th
sub(.*(\\d{5}).*, \\1, test)
[1] /th
sub(.*([0-9]{5}).*,\\1,test)
[1] 88958
I think the / in the source throws something off.
as the group capture appears to not be working, except the bracket
version
it did.
On Wed, May 5, 2010 at 2:35 PM, Gabor Grothendieck
ggrothendi...@gmail.com
wrote:
Here are two ways to extract 5 digits.
In the first one \\1 refers to the portion matched between the
parentheses in the regular expression.
In the second one strapply is like apply where the object to be worked
on is the first argument (array for apply, string for strapply) the
second modifies it (which dimension for apply, regular expression for
strapply) and the last is a function which acts on each value
(typically each row or column for apply and each match for strapply).
In this case we use c as our function to just return all the results.
They are returned in a list with one component per string but here
test is just a single string so we get a list one long and we ask for
the contents of the first component using [[1]].
# 1 - sub
sub(.*(\\d{5}).*, \\1, test)
# 2 - strapply - see http://gsubfn.googlecode.com
library(gsubfn)
strapply(test, \\d{5}, c)[[1]]
On Wed, May 5, 2010 at 5:13 PM, steven mosher mosherste...@gmail.com
wrote:
Given a text like
I want to be able to extract a matched regular expression from a piece
of
text.
this apparently works, but is pretty ugly
# some html
test-/trtrth88958/ththAbcdsef/thth67.8S/thth68.9\nW/thth26m/th
# a pattern to extract 5 digits
pattern-[0-9]{5}
# regexpr returns a start point[1] and an attribute match.length
attr(,match.length)
# get the substring from the start point to the stop point.. where
stop
=
start +length-1
answer-substr(test,regexpr(pattern,test)[1],regexpr(pattern,test)[1]+attr(regexpr(pattern,test),match.length)-1)
answer
[1] 88958
I tried using sub(pattern, replacement, x ) with a regexp that
captured
the
group. I'd found an example of this in the mails
but it didnt seem to work..
[[alternative HTML version deleted]]
__
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.
Re: [R] extracting a matched string using regexpr
I am using Vista. Another thing to try is strapply using the tcl
engine (assuming you do have tcltk capabilities) and the R engine. On
Vista R 2.11.0 patched I get the same result:
capabilities()[[tcltk]]
[1] TRUE
strapply(test, \\d{5}, c, engine = tcl)[[1]]
[1] 88958
strapply(test, \\d{5}, c, engine = R)[[1]]
[1] 88958
On Vista with R 2.9.2 I do get bad results:
test-/trtrth88958/ththAbcdsef/thth67.8S/thth68.9\nW/thth26m/th
sub(.*(\\d{5}).*, \\1, test)
[1]
/trtrth88958/ththAbcdsef/thth67.8S/thth68.9\nW/thth26m/th
sub(.*(\\d{5}).*, \\1, test, extended = TRUE)
[1]
/trtrth88958/ththAbcdsef/thth67.8S/thth68.9\nW/thth26m/th
R.version.string
[1] R version 2.9.2 Patched (2009-09-08 r49647)
win.version()
[1] Windows Vista (build 6002) Service Pack 2
On Wed, May 5, 2010 at 6:20 PM, steven mosher mosherste...@gmail.com wrote:
Hmm.
I have R11 just downloaded fresh.
I'll reload a new session..and revert. I will note that I've had trouble
with \\d
which is why I was using [0-9]
MAC here.
On Wed, May 5, 2010 at 3:00 PM, Gabor Grothendieck ggrothendi...@gmail.com
wrote:
That's not what I get:
test-/trtrth88958/ththAbcdsef/thth67.8S/thth68.9\nW/thth26m/th
sub(.*(\\d{5}).*, \\1, test)
[1] 88958
R.version.string
[1] R version 2.10.1 (2009-12-14)
I also got the above in R 2.11.0 patched as well.
On Wed, May 5, 2010 at 5:55 PM, steven mosher mosherste...@gmail.com
wrote:
test
[1]
/trtrth88958/ththAbcdsef/thth67.8S/thth68.9\nW/thth26m/th
sub(.*(\\d{5}).*, \\1, test)
[1] /th
sub(.*([0-9]{5}).*,\\1,test)
[1] 88958
I think the / in the source throws something off.
as the group capture appears to not be working, except the bracket
version
it did.
On Wed, May 5, 2010 at 2:35 PM, Gabor Grothendieck
ggrothendi...@gmail.com
wrote:
Here are two ways to extract 5 digits.
In the first one \\1 refers to the portion matched between the
parentheses in the regular expression.
In the second one strapply is like apply where the object to be worked
on is the first argument (array for apply, string for strapply) the
second modifies it (which dimension for apply, regular expression for
strapply) and the last is a function which acts on each value
(typically each row or column for apply and each match for strapply).
In this case we use c as our function to just return all the results.
They are returned in a list with one component per string but here
test is just a single string so we get a list one long and we ask for
the contents of the first component using [[1]].
# 1 - sub
sub(.*(\\d{5}).*, \\1, test)
# 2 - strapply - see http://gsubfn.googlecode.com
library(gsubfn)
strapply(test, \\d{5}, c)[[1]]
On Wed, May 5, 2010 at 5:13 PM, steven mosher mosherste...@gmail.com
wrote:
Given a text like
I want to be able to extract a matched regular expression from a
piece
of
text.
this apparently works, but is pretty ugly
# some html
test-/trtrth88958/ththAbcdsef/thth67.8S/thth68.9\nW/thth26m/th
# a pattern to extract 5 digits
pattern-[0-9]{5}
# regexpr returns a start point[1] and an attribute match.length
attr(,match.length)
# get the substring from the start point to the stop point.. where
stop
=
start +length-1
answer-substr(test,regexpr(pattern,test)[1],regexpr(pattern,test)[1]+attr(regexpr(pattern,test),match.length)-1)
answer
[1] 88958
I tried using sub(pattern, replacement, x ) with a regexp that
captured
the
group. I'd found an example of this in the mails
but it didnt seem to work..
__
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.
Re: [R] extracting a matched string using regexpr
Thnks,
perhaps we should report it
On Wed, May 5, 2010 at 4:52 PM, Gabor Grothendieck
ggrothendi...@gmail.comwrote:
I am using Vista. Another thing to try is strapply using the tcl
engine (assuming you do have tcltk capabilities) and the R engine. On
Vista R 2.11.0 patched I get the same result:
capabilities()[[tcltk]]
[1] TRUE
strapply(test, \\d{5}, c, engine = tcl)[[1]]
[1] 88958
strapply(test, \\d{5}, c, engine = R)[[1]]
[1] 88958
On Vista with R 2.9.2 I do get bad results:
test-/trtrth88958/ththAbcdsef/thth67.8S/thth68.9\nW/thth26m/th
sub(.*(\\d{5}).*, \\1, test)
[1]
/trtrth88958/ththAbcdsef/thth67.8S/thth68.9\nW/thth26m/th
sub(.*(\\d{5}).*, \\1, test, extended = TRUE)
[1]
/trtrth88958/ththAbcdsef/thth67.8S/thth68.9\nW/thth26m/th
R.version.string
[1] R version 2.9.2 Patched (2009-09-08 r49647)
win.version()
[1] Windows Vista (build 6002) Service Pack 2
On Wed, May 5, 2010 at 6:20 PM, steven mosher mosherste...@gmail.com
wrote:
Hmm.
I have R11 just downloaded fresh.
I'll reload a new session..and revert. I will note that I've had trouble
with \\d
which is why I was using [0-9]
MAC here.
On Wed, May 5, 2010 at 3:00 PM, Gabor Grothendieck
ggrothendi...@gmail.com
wrote:
That's not what I get:
test-/trtrth88958/ththAbcdsef/thth67.8S/thth68.9\nW/thth26m/th
sub(.*(\\d{5}).*, \\1, test)
[1] 88958
R.version.string
[1] R version 2.10.1 (2009-12-14)
I also got the above in R 2.11.0 patched as well.
On Wed, May 5, 2010 at 5:55 PM, steven mosher mosherste...@gmail.com
wrote:
test
[1]
/trtrth88958/ththAbcdsef/thth67.8S/thth68.9\nW/thth26m/th
sub(.*(\\d{5}).*, \\1, test)
[1] /th
sub(.*([0-9]{5}).*,\\1,test)
[1] 88958
I think the / in the source throws something off.
as the group capture appears to not be working, except the bracket
version
it did.
On Wed, May 5, 2010 at 2:35 PM, Gabor Grothendieck
ggrothendi...@gmail.com
wrote:
Here are two ways to extract 5 digits.
In the first one \\1 refers to the portion matched between the
parentheses in the regular expression.
In the second one strapply is like apply where the object to be
worked
on is the first argument (array for apply, string for strapply) the
second modifies it (which dimension for apply, regular expression for
strapply) and the last is a function which acts on each value
(typically each row or column for apply and each match for strapply).
In this case we use c as our function to just return all the results.
They are returned in a list with one component per string but here
test is just a single string so we get a list one long and we ask for
the contents of the first component using [[1]].
# 1 - sub
sub(.*(\\d{5}).*, \\1, test)
# 2 - strapply - see http://gsubfn.googlecode.com
library(gsubfn)
strapply(test, \\d{5}, c)[[1]]
On Wed, May 5, 2010 at 5:13 PM, steven mosher
mosherste...@gmail.com
wrote:
Given a text like
I want to be able to extract a matched regular expression from a
piece
of
text.
this apparently works, but is pretty ugly
# some html
test-/trtrth88958/ththAbcdsef/thth67.8S/thth68.9\nW/thth26m/th
# a pattern to extract 5 digits
pattern-[0-9]{5}
# regexpr returns a start point[1] and an attribute match.length
attr(,match.length)
# get the substring from the start point to the stop point.. where
stop
=
start +length-1
answer-substr(test,regexpr(pattern,test)[1],regexpr(pattern,test)[1]+attr(regexpr(pattern,test),match.length)-1)
answer
[1] 88958
I tried using sub(pattern, replacement, x ) with a regexp that
captured
the
group. I'd found an example of this in the mails
but it didnt seem to work..
[[alternative HTML version deleted]]
__
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.
Re: [R] extracting a matched string using regexpr
Yes, you could bring it up on the R-sig-mac or file a bug report.
On Wed, May 5, 2010 at 10:11 PM, steven mosher mosherste...@gmail.com wrote:
Thnks,
perhaps we should report it
On Wed, May 5, 2010 at 4:52 PM, Gabor Grothendieck ggrothendi...@gmail.com
wrote:
I am using Vista. Another thing to try is strapply using the tcl
engine (assuming you do have tcltk capabilities) and the R engine. On
Vista R 2.11.0 patched I get the same result:
capabilities()[[tcltk]]
[1] TRUE
strapply(test, \\d{5}, c, engine = tcl)[[1]]
[1] 88958
strapply(test, \\d{5}, c, engine = R)[[1]]
[1] 88958
On Vista with R 2.9.2 I do get bad results:
test-/trtrth88958/ththAbcdsef/thth67.8S/thth68.9\nW/thth26m/th
sub(.*(\\d{5}).*, \\1, test)
[1]
/trtrth88958/ththAbcdsef/thth67.8S/thth68.9\nW/thth26m/th
sub(.*(\\d{5}).*, \\1, test, extended = TRUE)
[1]
/trtrth88958/ththAbcdsef/thth67.8S/thth68.9\nW/thth26m/th
R.version.string
[1] R version 2.9.2 Patched (2009-09-08 r49647)
win.version()
[1] Windows Vista (build 6002) Service Pack 2
On Wed, May 5, 2010 at 6:20 PM, steven mosher mosherste...@gmail.com
wrote:
Hmm.
I have R11 just downloaded fresh.
I'll reload a new session..and revert. I will note that I've had trouble
with \\d
which is why I was using [0-9]
MAC here.
On Wed, May 5, 2010 at 3:00 PM, Gabor Grothendieck
ggrothendi...@gmail.com
wrote:
That's not what I get:
test-/trtrth88958/ththAbcdsef/thth67.8S/thth68.9\nW/thth26m/th
sub(.*(\\d{5}).*, \\1, test)
[1] 88958
R.version.string
[1] R version 2.10.1 (2009-12-14)
I also got the above in R 2.11.0 patched as well.
On Wed, May 5, 2010 at 5:55 PM, steven mosher mosherste...@gmail.com
wrote:
test
[1]
/trtrth88958/ththAbcdsef/thth67.8S/thth68.9\nW/thth26m/th
sub(.*(\\d{5}).*, \\1, test)
[1] /th
sub(.*([0-9]{5}).*,\\1,test)
[1] 88958
I think the / in the source throws something off.
as the group capture appears to not be working, except the bracket
version
it did.
On Wed, May 5, 2010 at 2:35 PM, Gabor Grothendieck
ggrothendi...@gmail.com
wrote:
Here are two ways to extract 5 digits.
In the first one \\1 refers to the portion matched between the
parentheses in the regular expression.
In the second one strapply is like apply where the object to be
worked
on is the first argument (array for apply, string for strapply) the
second modifies it (which dimension for apply, regular expression
for
strapply) and the last is a function which acts on each value
(typically each row or column for apply and each match for
strapply).
In this case we use c as our function to just return all the
results.
They are returned in a list with one component per string but here
test is just a single string so we get a list one long and we ask
for
the contents of the first component using [[1]].
# 1 - sub
sub(.*(\\d{5}).*, \\1, test)
# 2 - strapply - see http://gsubfn.googlecode.com
library(gsubfn)
strapply(test, \\d{5}, c)[[1]]
On Wed, May 5, 2010 at 5:13 PM, steven mosher
mosherste...@gmail.com
wrote:
Given a text like
I want to be able to extract a matched regular expression from a
piece
of
text.
this apparently works, but is pretty ugly
# some html
test-/trtrth88958/ththAbcdsef/thth67.8S/thth68.9\nW/thth26m/th
# a pattern to extract 5 digits
pattern-[0-9]{5}
# regexpr returns a start point[1] and an attribute match.length
attr(,match.length)
# get the substring from the start point to the stop point.. where
stop
=
start +length-1
answer-substr(test,regexpr(pattern,test)[1],regexpr(pattern,test)[1]+attr(regexpr(pattern,test),match.length)-1)
answer
[1] 88958
I tried using sub(pattern, replacement, x ) with a regexp that
captured
the
group. I'd found an example of this in the mails
but it didnt seem to work..
__
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.
