similar to: install.packages bug (PR#8873)

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

Dear R-devel, I did a systematic comparison of write.csv with similar functions, and observed two asymptotic inefficiencies that could be improved. 1. write.csv is quadratic time (N^2) in the number of columns N. Can write.csv be improved to use a linear time algorithm, so it can handle CSV files with larger numbers of columns? For more details including figures and session info, please see

On 2/20/19 7:55 PM, Toby Hocking wrote: > Update: I have observed that stringi::stri_sub is linear time complexity, > and it computes the same thing as base::substring. figure > https://github.com/tdhock/namedCapture-article/blob/master/figure-substring-bug.png > source: > https://github.com/tdhock/namedCapture-article/blob/master/figure-substring-bug.R > > To me this is a

Hi all, (and especially hi to Tomas Kalibera who accepted my patch sent yesterday) I believe that I have found another bug, this time in the substring function. The use case that I am concerned with is when there is a single (character scalar) text/subject, and many substrings to extract. For example substring("AAAA", 1:4, 1:4) or more generally, N=1000

Hi all, I'm on Ubuntu 18.04, running R-4.0.0 which I compiled from source, and using valgrind I am always seeing the following message. Does anybody else see that? Is that a known false positive? Any ideas how to fix/suppress? Seems related to TRE, do I need to upgrade that? (base) tdhock at maude-MacBookPro:~/R/binsegRcpp$ R --vanilla -d valgrind -e 'extSoftVersion()' ==9565==

Dear R-devel, I am running mclapply with many iterations over a function that modifies nothing and makes no copies of anything. It is taking up a lot of memory, so it seems to me like this is a bug. Should I post this to bugs.r-project.org? A minimal reproducible example can be obtained by first starting a memory monitoring program such as htop, and then executing the following code while

Dear R-devel, A number of people have observed anecdotally that read.csv is slow for large number of columns, for example: https://stackoverflow.com/questions/7327851/read-csv-is-extremely-slow-in-reading-csv-files-with-large-numbers-of-columns I did a systematic comparison of read.csv with similar functions, and observed that read.csv is quadratic time (N^2) in the number of columns N, whereas

Update: I have observed that stringi::stri_sub is linear time complexity, and it computes the same thing as base::substring. figure https://github.com/tdhock/namedCapture-article/blob/master/figure-substring-bug.png source: https://github.com/tdhock/namedCapture-article/blob/master/figure-substring-bug.R To me this is a clear indication of a bug in substring, but again it would be nice to have

It is known, with a known workaround, see e.g. https://www.stats.ox.ac.uk/pub/bdr/memtests/README.txt . Set suppressions in ~/.valgrindrc, e.g. the CRAN check machine has --suppressions=/data/blackswan/ripley/wcsrtombs.supp It is an issue in your OS (glibc), not TRE nor R. On 10/06/2020 00:21, Toby Hocking wrote: > Hi all, > > I'm on Ubuntu 18.04, running R-4.0.0 which I

If anybody else has this issue, please add a comment on https://bugs.r-project.org/bugzilla/show_bug.cgi?id=17478 so we are more likely to get R-core to address this. Thanks Toby On Tue, Jun 4, 2019 at 2:58 PM Pages, Herve <hpages at fredhutch.org> wrote: > On 5/31/19 08:41, Toby Hocking wrote:... > > In my opinion install.packages should stop with an error (instead of a >

Dear R core developers, One feature from Python that I have been wanting in R is the ability to capture groups in regular expressions using names. Consider the following example in R. > notables <- c(" Ben Franklin and Jefferson Davis","\tMillard Fillmore") > name.rex <- "(?<first>[A-Z][a-z]+) (?<last>[A-Z][a-z]+)" > (parsed <-

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).

Well it's only a leak if you don't get the memory back after it returns, right? Anyway, one (untested by me) possibility is the copying of memory pages when the garbage collector touches objects, as pointed out by Radford Neal here: http://r.789695.n4.nabble.com/Re-R-devel-Digest-Vol-149-Issue-22-td4710367.html If so, I don't think this would be easily avoidable, but there may be

Toby, > On Sep 2, 2015, at 1:12 PM, Toby Hocking <tdhock5 at gmail.com> wrote: > > Dear R-devel, > > I am running mclapply with many iterations over a function that modifies > nothing and makes no copies of anything. It is taking up a lot of memory, > so it seems to me like this is a bug. Should I post this to > bugs.r-project.org? > > A minimal reproducible

I am using the .Call interface to call c++ code from R. For that, I am trying to create a dynamic library (mylib.so) using "R CMD SHLIB" by linking my own c++ code and an external c++ library (blitz++). The makefile works fine on my Mac, produces mylib.so and I am able to call .Call() from R, but on a linux server (I think Debian), I got the following error: ---------- /usr/bin/ld:

I am using the .Call interface to call c++ code from R. For that, I am trying to create a dynamic library (mylib.so) using "R CMD SHLIB" by linking my own c++ code and an external c++ library (blitz++). The makefile works fine on my Mac, produces mylib.so and I am able to call .Call() from R, but on a linux server (I think Debian), I got the following error: ---------- /usr/bin/ld:

Hi Toby, As Gabor pointed out the place where the various levers R CMD check supports is in the R-internals manual, but there is a link directly to that section in https://cloud.r-project.org/doc/manuals/r-release/R-exts.html#Checking-packages It could perhaps be more prominent, perhaps by moving the paragraph that appears in to before the detailed list of exact tests that are performed?

Hello, I 'd like to use some functions in myLib. So I do: library(myLib) Then I get this message: Error: package 'myLib' is not installed for 'arch=i386' > sessionInfo() R version 2.13.2 (2011-09-30) Platform: i386-pc-mingw32/i386 (32-bit) locale: [1] LC_COLLATE=French_France.1252 LC_CTYPE=French_France.1252 LC_MONETARY=French_France.1252 LC_NUMERIC=C

Hi all, I am having an issue related to installing packages on windows with R-3.6.0. When installing a package that is in use, I expected R to stop with an error. However I am getting a warning that the DLL copy was not successful, but the overall package installation IS successful. This is quite dangerous because the old DLL and the new R code could be incompatible. I am definitely not the

On Thu, 24 Oct 2024 13:23:56 -0400 Toby Hocking <tdhock5 at gmail.com> wrote: > The patch you are proposing to base R is > https://github.com/Rdatatable/data.table/issues/6566#issuecomment-2428912338 > right? Yes, it's this one, thank you for providing the link. Surprisingly, a very cursory check of 100 packages most downloaded from cloud.r-project.org in the last month