Displaying 20 results from an estimated 800 matches similar to: "Crash report: regexpr("a{2-}", "")"
2008 Apr 15
1
why does regexpr not work with '.'
Dear R Helpers,
I am running R 2.6.2 on a Windows XP machine.
I am trying to use regexpr to locate full stops in strings, but, without
success.
Here an example:-
f="a,b.c at d:" #define an arbitrary test string
regexpr(',',f) #find the occurrences of ',' in f - should be one at location
2
# and this is what regexpr finds
#[1] 2
2010 Jun 01
1
regexpr help (match.length=0)
R-help,
Sorry if this is more of a regex question than an R question. However,
help would be appreciated on my use of the regexpr function.
In the first example below, I ask for all characters (a-z) in 'abc123';
regexpr returns a 3-character match beginning at the first character.
> regexpr("[[:alpha:]]*", "abc123")
[1] 1
attr(,"match.length")
[1] 3
2010 May 05
1
extracting a matched string using regexpr
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<-"</tr><tr><th>88958</th><th>Abcdsef</th><th>67.8S</th><th>68.9\nW</th><th>26m</th>"
# a pattern to extract 5 digits
> pattern<-"[0-9]{5}"
#
2007 Jun 29
2
regexpr
Hi,
I 'd like to match each member of a list to a target string, e.g.
------------------------------
mylist=c("MN","NY","FL")
g=regexpr(mylist[1], "Those from MN:")
if (g>0)
{
"On list"
}
------------------------------
My question is:
How to add an end-of-string symbol '$' to the to-match string? so that 'M'
won't
2004 Feb 06
3
a grep/regexpr problem
Hi,
I'm trying to parse lines of the form:
dan001.hin (0): fingerprint={256, 411, 426, 947, 973, 976}
What I need is the sequence of number between {}. I'm using grep as
match <- grep("{([0-9,\s]*)}",s,perl=T,value=T)
where s is a character vector.
But all I get is the whole string s. I tried using regexpr in an attempt
to get just the sequence I wanted:
match <-
2011 Sep 29
2
String manipulation with regexpr, got to be a better way
Help-Rs,
I'm doing some string manipulation in a file where I converted a string date in mm/dd/yyyy format and returned the date yyyy.
I've used regexpr (hat tip to Gabor G for a very nice earlier post on this function) in steps (I've un-nested the code and provided it and an example of what I did below. My question is: is there a more efficient way to do this. Specifically is
2008 Oct 01
1
regexpr syntax question
Greetings R list,
I am stuck on a simple syntax problem. I want to list all files in a directory, excluding files of a certain type. I have tried pattern matching as follows:
a <- list.files(data, full.name = TRUE, pattern != ".xml") # exclude all .xml files
The warning returns that my syntax is incorrect. I have read the regexpr help files and search old posts to no
2005 Aug 03
2
regexpr and portability issue
Dear all--
I am still forging my first arms with R and I am fighting with regexpr() as
well as portability between unix and windoz. I need to extract barcodes from
filenames (which are located between a double and single underscore) as well
as the directory where the filename is residing. Here is the solution I came
to:
aFileName <-
2010 Jun 02
2
regexpr mystery can not remove trailing spaces
Dear all
I encountered strange problem with regexpr replacement
I made this character object
str <- "02.06.10 12:40 "
> str(str)
chr "02.06.10 12:40 "
I read in an object which seems to be quite similar
> str(as.character(becva$V1)[1])
chr "02.06.10 12:40 "
However I can not remove trailing spaces from it
> sub(' +$',
2006 Oct 27
1
Regexpr. analyzer
Hi!
I want to index html files, but w/o the tags, so I was thinking either I
remove them before I index it (expensive), or put up an RegExpAnalyzer.
BTW, when using an analyzer, does that mean that everything which it
declines (i.e. the RegExpAnalyzer doesn''t match) won''t be put into the
index files (i.e. blows it up)?
I came up with a simple test, which didn''t
2012 Aug 06
5
regexpr with accents
Hello,
I have build a syntax to find out if a given substring is included in a larger string that works like this:
d1$V1[regexpr("some text = 9",d1$V2)>0] <- 9
and this works all right till "some text" contains standard ASCII set. However, it does not work when accents are included as the following:
d1$V1[regexpr("some t?xt = 9",d1$V2)>0] <- 9
I have
2003 Aug 13
7
Regexpr with "."
I'm trying to use the regexpr function to locate the decimal in a character
string. Regardless of the position of the decimal, the function returns 1.
For example,
> regexpr(".", "Female.Alabama")
[1] 1
attr(,"match.length")
[1] 1
In trying to figure out what was going on here, I tried the below command:
> gsub(".", ",",
2008 Aug 20
3
vector operation using regexpr?
Hi,
Here's my problem... I have a data frame with three columns containing
strings. The first columns is a simple character. I want to get the
index of that character in the second column and use it to extract the
item from the third column. I can do this using a scalar method. But
I'm not finding a vector method. An example is below.
col1 col2 col3
'L'
2002 Jun 24
3
RegExpr in ---exclude
Hi there,
is it possible to use regular expressions in the exclude-paramter of rsync ?
For example:
rsync --exclude "/path/to/*/[Ff][Oo][Ll][Dd][Ee][Rr]"
I've tried it, but it will take no effect.
--
SET THE CONTROLS
FOR THE HEART OF THE SUN
Jens
2010 Dec 06
2
less than full rank contrast methods
I'd like to make a less than full rank design using dummy variables
for factors. Here is some example data:
when <- data.frame(time = c("afternoon", "night", "afternoon",
"morning", "morning", "morning",
"morning", "afternoon", "afternoon"),
2007 Jul 26
3
substituting dots in the names of the columns (sub, gsub, regexpr)
Dear R users,
I have the following two problems, related to the function sub, grep,
regexpr and similia.
The header of the file(s) I have to import is like this.
c("y (m)", "BD (g/cm3)", "PR (Mpa)", "Ks (m/s)", "SP g./g.", "P
(m3/m3)", "theta1 (g/g)", "theta2 (g/g)", "AWC (g/g)")
To get rid of spaces and
2010 Sep 23
4
[Bug 1825] New: ipv64_normalise_mapped()'s memset should use a4, not addr, for clarity
https://bugzilla.mindrot.org/show_bug.cgi?id=1825
Summary: ipv64_normalise_mapped()'s memset should use a4, not
addr, for clarity
Product: Portable OpenSSH
Version: 5.6p1
Platform: All
OS/Version: All
Status: NEW
Severity: trivial
Priority: P2
Component: Miscellaneous
2011 Apr 07
1
Two questions about metacharacter in regexprs and function return
for the script, please kindly see the script below. At line 10 and line 13,
my problems occurs.
The first one is I try to retrieve the gene official name from a column of a
table. The pattern of official name is something starting with gene_name.
For detail problems, please see the according lines.
Any suggestions are appreciated
example of matching source (extract the Nnat, sometime it would
2007 Nov 02
1
R timeDate does not allow seconds?
Hello, Sorry if anyone gets this message twice, as my mailserver may not
be working.
Thanks for your response. Your idea makes a lot of sense to me, but I've
been unable to get seconds to work.
I ended up with this format finally:
"2007-10-31_16:20:22"
Problem is I am unable to get it recognized as a date using timeDate():
R>
2013 Mar 12
5
extract values
Hello all!
I have a problem to extract values greater that for example 1820.
I try this code: x[x[,1]>1820,]->x1
Please help me!
Thank you!
The data structure is:
structure(c(2.576, 1.728, 3.434, 2.187, 1.928, 1.886, 1.2425,
1.23, 1.075, 1.1785, 1.186, 1.165, 1.732, 1.517, 1.4095, 1.074,
1.618, 1.677, 1.845, 1.594, 1.6655, 1.1605, 1.425, 1.099, 1.007,
1.1795, 1.3855, 1.4065, 1.138, 1.514,