similar to: matching character substrings

Hi, I wonder if there's a good intro to the pattern matching using R? I'm a perl programer and find it too confusing and complex to use regular expressions under R. For instance, why does pmatch("d","ad") returns NULL? How would I call the functions in order to match any portion of the string? Under what circumstances shall backslush be used? I try to extract all

Hello, What about an `invert` argument in grep, to return elements that are *not* matching a regular expression : R> grep("pink", colors(), invert = TRUE, value = TRUE) would essentially return the same as : R> colors() [ - grep("pink", colors()) ] I'm attaching the files that I modified (against today's tarball) for that purpose. Cheers, Romain --

I need to know which strings of an array that are in another array. What a best solution? Tks, Francisco. ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ Francisco Júnior, Computer Science - UFPE-Brazil "One life has more value that the world whole" ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

Dear All, I wonder if you could help me. I have a table with a series of sites that I would like to sample from. The table has 5 columns: ID X Coordinate Y Coordinate Value Factor The conditions are that each site can be selected more than once and the probability of it being selected (or sampled) is proportional to a factor located in column 'Factor' I am novice in terms of R, and

Hi folks, Can anyone suggest an efficient way to do "matching without replacement", or "one-to-one matching"? pmatch() doesn't quite provide what I need... For example, lookupTable <- c("a","b","c","d","e","f") matchSample <- c("a","a","b","d") ##Normal match()

On Wed, 13 Dec 2023 09:04:18 +0100 Hilmar Berger via R-devel <r-devel at r-project.org> wrote: > Still, I feel that default partial matching cripples the functionality > of data.frame for larger tables. Changing the default now would require a long deprecation cycle to give everyone who uses `[.data.frame` and relies on partial matching (whether they know it or not) enough time to

Dear Ivan, thanks a lot, that is helpful. Still, I feel that default partial matching cripples the functionality of data.frame for larger tables. Thanks again and best regards Hilmar On 12.12.23 13:55, Ivan Krylov wrote: > ? Mon, 11 Dec 2023 21:11:48 +0100 > Hilmar Berger via R-devel <r-devel at r-project.org> ?????: > >> What was unexpected is that in this case was that

Hi Hilmar and Ivan, I have used your code examples to write a blog post about this topic, which has figures that show the asymptotic time complexity of the various approaches, https://tdhock.github.io/blog/2023/df-partial-match/ The asymptotic complexity of partial matching appears to be quadratic O(N^2) whereas the other approaches are asymptotically faster: linear O(N) or log-linear O(N log N).

Dear R-Helpers, this is my first post ever to a mailing list, so please feel free to point out any missunderstandings on my side regarding the conventions of this mailing list. My problem: Assuming the following character vector is given: names <- c("filia Maria", "vidua Joh Dirck Kleve (oo 02.02.1732)", "Bernardus Engelb Franciscus Linde j.u.Doktor referendarius

Dear All, I have a data set with the following structure: [A], [a], [B], [b] where [A] and [B] are measurements and [a] and [b] are the associated uncertainties. I produce [B]/[A] vs. [A] plots in R and would like to show uncertainties as error ellipses (rather than error bars). Would this be relatively easy to do in R? I would appreciate any help on this Thanks a lot Tibi

Hi all, This occurred in R-2.11.0 (WinXP). The R-help page of .[ says that: "Character indices can in some circumstances be partially matched (see pmatch) to the names or dimnames of the object being subsetted (but never for subassignment). Unlike S (Becker et al p. 358)), R has never used partial matching when extracting by [, and as from R 2.7.0 partial matching is not by default used by

Hi, I have a simple question. Suppose I have a string "x$Expensive". I want to find the position of the $ in this string; i.e., I want a function that returns 2. I tried grep, regexpr, etc with no luck, unless I'm just using them incorrectly. Any suggestions? Thanks, Walt ________________________ Walter R. Paczkowski, Ph.D. Data Analytics Corp. 44 Hamilton Lane Plainsboro,

I'm a relative R novice, and sometimes the simple things trip me up. Suppose I have a <- c("apple", "pear") and I want a logical vector of whether each of these strings contains "ear" (in this case, F T). What is the idiom? Quizzically, Mark Lindeman

Hi All, I am trying to match two character arrays (email lists) using either pmatch(), match() or charmatch() functions. However the function is "missing" some matches due to differences in the cases of some letters between the two arrays. Is there any way to disable case sensitivity or is there an entirely better way to match two character arrays that have identical entries but written

Recently working with strings and data I have found a small problem. Windows XP R 1.8.1 Reading data from a "txt file" with readLine. finding a specific line with "grep" command, all OK. but here comes the problem... After finding the correct line(s) i need to find a substring inside each string. In this case "tabs" I think it represented by "\t" in the

For example, strings <- c("aaaa", "bbbb","ccba"). How to get "aaaa", "bbbb" that do not contain "ba" ? _________________________________________________________________ [[alternative HTML version deleted]]

Hi, How can I use a substring match as a condition in a subset command? Sth like this: subset(input, field1=="blah1" & field2=="blah2") # but now with substring match in field2 subset(input, field1=="blah1" & field3 *substringmatch* "blah3") I've tried with gsub, but it won't work: subset(input, field1=="blah1" &

The pmatch help (see also section 4.3.2 in the R Language Definition) claims that pmatch with duplicates.ok=FALSE provides the same functionality as R's argument matching algorithm, modulo how empty strings are matched. Here's an undocumented inconsistency between pmatch and R's argument matching algorithm: > sessionInfo() R version 3.0.1 (2013-05-16) Platform:

Source: xen Version: 4.0.1~rc5-1 Severity: serious Justification: FTBFS User: debian-sparc at lists.debian.org Usertags: sparc Hi, your package no longer builds on sparc: | make[1]: Leaving directory `/build/buildd-sivp_0.5.2-2-sparc-3aHxSt/sivp-0.5.2' | SCI_DISABLE_TK=1 SCI_JAVA_ENABLE_HEADLESS=1 DOCBOOK_ROOT=/usr/share/sgml/docbook/stylesheet/xsl/nwalsh \ | /usr/bin/scilab -nw -f

Dear R-experts, I just tracked down a nasty bug in a dynamically parametrized function to wrong argument matching. As we get more and more complex applications build on top of R (like bioconductor) partial matching gets more and more dangerous. I would like to deactivate partial matching in R (partial argument matching as well as partial matching of list elements), e.g. using an environment