Displaying 20 results from an estimated 9000 matches similar to: "segfault in gregexpr()"
2006 Nov 07
1
Gregexpr - extract results with lapply
Gregexpr - extract results with lapply
Hello,
I need to extract sequences of three upper case letters in a string. In
other words, in this string:
str <-c("ABC", "this WOUld be gOOD")
The result I'm looking for is ABC WOU OOD.
With gregexpr, I can get the position and length of the sequences
gregexpr('[A-Z]{3}',str,perl=TRUE)
[[1]]
[1] 1
2007 Jul 21
2
dict package: dictionary data structure for R
Hi all,
The dict package provides a dictionary (hashtable) data
structure much like R's built-in environment objects, but with the
following differences:
- The Dict class can be subclassed.
- Four different hashing functions are implemented and the user can
specify which to use when creating an instance.
I'm sending this here as opposed to R-packages because this package
will
2005 Nov 03
3
Search within a file
Hi,
I am looking for a way to search a file for position of some expression,
from within R. My current code:
sha1Pos = gregexpr("<sha1>", readChar(filename,
file.info(filename)$size))[[1]]
Works fine for small files, but text files I will be working with might get
up to Gb range, so I was trying to accomplish the same without loading the
whole file into R.
I realize this is
2011 Aug 17
2
question regarding gregexpr and read.table
Hi,
I have a silly question regarding the usage of two commands: read.table and
gregexpr:
For read.table, if I read a matrix and set header = T, I found that all the
dash ("-") becomes dots (".")
A = read.table("Matrix.txt", sep = "\t", header = F)
A[1,1]
# "A-B-C-D".
A = read.table("Matrix.txt", sep = "\t", header = T)
2009 Feb 25
1
Using gregexpr with multiple search elements
Dear list,
I am trying to use gregexpr to see if entries in a dataframe have
either of two possible values for a string.
here's an example
text<-c("fat", "rat", "cat", "dog", "log", "fish")
If I just wanted to find if any one of the elements in text match the
pattern "at" I would do
gregexpr("\\at", text)
2019 Feb 19
1
patch for gregexpr(perl=TRUE)
Hi all,
Several people have noticed that gregexpr is very slow for large subject
strings when perl=TRUE is specified.
-
https://stackoverflow.com/questions/31216299/r-faster-gregexpr-for-very-large-strings
-
http://r.789695.n4.nabble.com/strsplit-perl-TRUE-gregexpr-perl-TRUE-very-slow-for-long-strings-td4727902.html
- https://stat.ethz.ch/pipermail/r-help/2008-October/178451.html
I figured out
2007 Oct 10
4
gregexpr (PR#9965)
Full_Name: Peter Dolan
Version: 2.5.1
OS: Windows
Submission from: (NULL) (128.193.227.43)
gregexpr does not find all matching substrings if the substrings overlap:
> gregexpr("abab","ababab")
[[1]]
[1] 1
attr(,"match.length")
[1] 4
It does work correctly in Version 2.3.1 under linux.
2010 Aug 13
2
64 bit RSQLite
Hi folks,
Ubuntu 10.04 64 bit
Where can I find 64 bit RSQLite?
It seems not there;
RSQLite: SQLite interface for R
http://cran.r-project.org/web/packages/RSQLite/index.html
TIA
B.R.
Stephen L
2008 Jun 04
2
RSQLite bug fix for install with icc
Seth,
I encountered problems installing RSQLite, R-2.7.0, on RHEL4 using
Intel 10.1 icc, My sysadmin helped me track down the problem and
kindly forwarded me the fix, which corrected the problem.
What follows is from the sysadmin. Mark
I looked at the error, looks like there is a bug in the source code.
I've attached a new tarball, hopefully fixed.
I added
#include <sys/types.h>
2012 Mar 30
1
How to use access results of gregexpr in data frames
Hello,
I'm trying to figure out how to find the index of the second occurrence of "/" in a string (which happens to represent a date) within a data frame column.
I've used the following code successfully to find the first instance of "/".
dframe <- data.frame(date=c("5/14/2011", "4/7/2011"))
dframe$x1 <- regexpr("/", dframe[, 1])
2006 Oct 07
2
gregexpr in R 2.3.0 != gregexpr in R 2.4.0
Hi all
I have a question regarding differences in the way gregpexr works in R 2.3.0 and R 2.4.0.
In R 2.3.0, this is what happens:
> gregexpr(" [a-z] [a-z] ", " a b c d e f ", perl=T)
[[1]]
[1] 1 3 5 7 9
attr(,"match.length")
[1] 5 5 5 5 5
... while in R 2.4.0, this is what happens:
> gregexpr(" [a-z] [a-z] ", " a b c d e f ", perl=T)
2008 Dec 12
4
gregexpr - match overlap mishandled (PR#13391)
Full_Name: Reid Thompson
Version: 2.8.0 RC (2008-10-12 r46696)
OS: darwin9.5.0
Submission from: (NULL) (129.98.107.177)
the gregexpr() function does NOT return a complete list of global matches as it
should. this occurs when a pattern matches two overlapping portions of a
string, only the first match is returned.
the following function call demonstrates this error (although this is not how I
2008 Dec 12
4
gregexpr - match overlap mishandled (PR#13391)
Full_Name: Reid Thompson
Version: 2.8.0 RC (2008-10-12 r46696)
OS: darwin9.5.0
Submission from: (NULL) (129.98.107.177)
the gregexpr() function does NOT return a complete list of global matches as it
should. this occurs when a pattern matches two overlapping portions of a
string, only the first match is returned.
the following function call demonstrates this error (although this is not how I
2006 Feb 01
1
Word boundaries and gregexpr in R 2.2.1
Hi
I have a question concerning how to match word boundaries which I bet has a very simple answer, but I haven't found it with trial and error nor by searching the help archives for the terms in the subject line. The problem is this: I have a vector of two character strings.
text<-c("This is a first example sentence.", "And this is a second example sentence.")
If I
2009 Jan 29
4
Side-effects of require() vs library() on x86_64 aka amd64
RDieHarder fails its regression tests on x86_64 (aka "amd64") at CRAN (using
Debian), and I see the same on Ubuntu 8.10 in 64 bit. No issues on 32bit.
One odd thing is that the program behaves well if run via
R --no-save < tests/RDieHarder.R
but NOT when started using
R --slave < tests/RDieHarder.R
as R CMD check does.
So I tried different things related to startup
2008 Sep 15
2
S4 coercion responsibility
Should functions or the user be responsible for coercing an S4 object
argument containing the proper object (and thus should below be
considered a bug in the packages or not)?
The example is with RSQLite but the same thing happens with RMySQL, and
other DBI packages.
> library("RSQLite") Loading required package: DBI
> m <- dbDriver("SQLite")
> con <-
2006 Feb 01
1
Word boundaries and gregexpr in R 2.2.1 (PR#8547)
Full_Name: Stefan Th. Gries
Version: 2.2.1
OS: Windows XP (Home and Professional)
Submission from: (NULL) (68.6.34.104)
The problem is this: I have a vector of two character strings.
> text<-c("This is a first example sentence.", "And this is a second example
sentence.")
If I now look for word boundaries with regexpr, this is what I get:
>
2010 Jan 19
2
Help deciphering segfault in make check
Dear R Help,
I work with the Sage project, and we are trying to improve the ability
to use R through Sage. Most things work, but make check seems to
cause problems on certain platforms, and now that we want to upgrade
to 2.10.1 I thought we should ask for help!
R builds just fine on both Mac and Linux, but some things in make
check seem to break on certain Linux boxes that don't on Mac or
2012 Nov 02
2
backreferences in gregexpr
Hi Folks,
I'm trying to extract just the backreferences from a regex.
> temp = "abcd1234abcd1234"
> regmatches(temp, gregexpr("(?:abcd)(1234)", temp))
[[1]]
[1] "abcd1234" "abcd1234"
What I would like is:
[1] "1234" "1234"
Note: I know I can just match 1234 here, but the actual example is
complicated enough that I have to
2008 Oct 31
1
gregexpr slow and increases exponentially with string length --> how to speed it up?
Dear All,
I have a long string and need to search for regular expressions in
there. However it becomes horribly slow as the string length
increases.
Below is an example: when "i" increases by 5, the time spent increases
by more! (my string is 11,000,000 letters long!)
I also noticed that
- the search time increases dramatically with the number of matches found.
- the perl=T option