similar to: strcapture enhancement

Michael, thanks for looking at my first issue with utils::strcapture. Another issue is how it deals with lines that don't match the pattern. Currently it gives an error > strcapture("(.+) (.+)", c("One 1", "noSpaceInLine", "Three 3"), proto=list(Name="", Number=0)) Error in strcapture("(.+) (.+)", c("One 1",

If there are any matches then strcapture can see if the pattern has the same number of capture expressions as the prototype has columns and give an error if not. That seems appropriate. If there are no matches, then there is no easy way to see if the prototype is compatible with the pattern, so should strcapture just assume the best and fill in the prototype with NA's? Should there be

I noticed a problem in the strcapture from R-devel (2016-09-27 r71386), when the text contains a missing value and perl=TRUE. { # NA in text input should map to row of NA's in output, without warning r9p <- strcapture(perl = TRUE, "(.).* ([[:digit:]]+)", c("One 1", NA, "Fifty 50"), data.frame(Initial=factor(), Number=numeric())) e9p <-

It is also not catching the cases where the number of capture expressions does not match the number of entries in proto. I think all of the following should give an error about the mismatch. > strcapture("(.)(.)", c("ab", "cde", "fgh", "ij", "lm"), proto=list(A="",B="",C="")) A B C 1 a b cd 2 d

The new behavior is that it yields NAs when the pattern does not match (like strptime) and for empty captures in a matching pattern it yields the empty string, which is consistent with regmatches(). Michael On Wed, Sep 21, 2016 at 2:21 PM, William Dunlap <wdunlap at tibco.com> wrote: > If there are any matches then strcapture can see if the pattern has the same > number of capture

Hi Bill, This is a bug in regexec() and I will commit a fix. Thanks for the report, Michael On Tue, Oct 4, 2016 at 1:40 PM, William Dunlap <wdunlap at tibco.com> wrote: > I noticed a problem in the strcapture from R-devel (2016-09-27 r71386), when > the text contains a missing value and perl=TRUE. > > { > # NA in text input should map to row of NA's in output,

Hi Bill, Thanks, another good suggestion. strcapture() now returns NAs for non-matches. It's nice to have someone kicking the tires on that function. Michael On Wed, Sep 21, 2016 at 12:11 PM, William Dunlap via R-devel <r-devel at r-project.org> wrote: > Michael, thanks for looking at my first issue with utils::strcapture. > > Another issue is how it deals with lines that

I do think keeping the default behavior is desirable for backwards compatibility; my suggestion is not to change default behavior but to add an optional argument that allows a different behavior. Although this can be implemented in a user-defined function, retaining empty matches facilitates programmatic use, and seems to be something that should be available in base R. It is available, for

Hi, I don't know what I am doing wrong to the toupper does not seem working in sub + regex. The following returns 's' not the upper class 'S' as I expect: sub("q_([a-z])[a-zA-Z]*",toupper('\\1'),"q_sviRaw") Can someone tell me where I did wrong? Thanks, Richard [[alternative HTML version deleted]]

Using a non-capturing group, "(?:...)" instead of "(...)", simplifies my example a bit > x <- c("Groucho <groucho at marx.com>", "<chico at marx.com>", "Harpo") > strcapture("([[:alpha:]]+)?(?: *<([[:alpha:]. ]+@[[:alpha:]. ]+)>)?", x, proto=data.frame(Name=character(), Address=character(),

> grep("f[0-9]+=", "f1=5,f22=3,", value = T) [1] "f1=5,f22=3," How do I make the line output c("f1", "f22") instead? (Actually, c(1,22) would be even better). Thank you. -- View this message in context: http://r.789695.n4.nabble.com/Quick-GREP-challenge-tp2339486p2339486.html Sent from the R help mailing list archive at Nabble.com.

Currently sub(perl=TRUE) allows you to specify \U and \L in the replacement argument so that the rest of the subpatterns in the line (the \\<digit> things) will be converted to upper or lower case, respectively. perl also also has a \E operator to end these case conversions for the rest of the subpatterns (so they retain whatever case they had in the original text). For symmetry's sake

I wanted to raise the possibility of improving strcapture performance in cases where perl = TRUE. I believe we can do this in a non-breaking way by calling regexpr instead of regexec (conditionally when perl = TRUE). To illustrate this I've put together a 'proof of concept' function called strcapture2 that utilises output from regexpr directly (following a very nice substring approach

I don't care much for regmatches and haven't tried strextract, but I think replacing the character(0) by NA_character_ is almost always inappropriate if the match information comes from gregexpr. I think strcapture() does a pretty good job of what I think you are trying to do. Perhaps adding an argument to map no match to NA instead of "" would give you just what you wanted.

Hi list, Can anyone tell my why the following does not work? Thanks a lot! Your help is very much appreciated. DF = data.frame(read.table(textConnection(" B C D E F G 8025 1995 0 4 1 2 8025 1997 1 1 3 4 8026 1995 0 7 0 0 8026 1996 1 2 3 0 8026 1997 1 2 3 1 8026 1998 6 0 0 4 8026 1999 3 7 0 3 8027 1997 1 2 3 9 8027 1998 1 2 3 1 8027 1999

Hello R Folks... I've been looking around the 'net and I see many complex solutions in various languages to this question, but I have a pretty simple need (and I'm not much good at regex). I want to use a chemical formula as a function argument. The formula would be in "Hill order" which is to list C, then H, then all other elements in alphabetical order. My

= numbersToWords - convert your integers and floats to english or japaneese words,or translate it into american currency - This plugin was created from a solution to the ruby quiz (english numbers) by Matthew D Moss. I modified the code to work as a rails plugin and added the to_dollars method. - the to_dollars method will work with integers and floats - the to_english and to_japaneese methods

I think that's a good reason for not including this in regmatches; you're right, its name is somewhat suggestive of yielding matches. Also, that sounds like a great design for strcapture with an atomic prototype. Best, CG

Hi, I have the following code to randomly generate the points: csr <-function(n=60){ x=runif(n) y=runif(n) f=cbind(x,y) } plot(csr()) I wonder how to code to make the first twenty points to be BLUE; second twenty points to be RED; the last twenty points to be GREEN? Thanks, Sam --------------------------------- [[alternative HTML version deleted]]

I''ve created a plugin that lets you spell out numbers (under one thousand, in English, for now). Examples: >> 23.spell => "twenty-three" >> 23.spell :noun => ''person'' => "twenty-three people" >> (23.14).spell_currency => "twenty-three dollars and fourteen cents" >>