Changes in R

We give a selection of the most important changes in R 4.2.0 and of subsequent bug fixes for the Windows port of R. We also provide statistics on source code commits.

Tomas Kalibera (

Czech Technical University, Czech Republic

) , Sebastian Meyer (

Friedrich-Alexander-Universität Erlangen-Nürnberg, Germany

) , Kurt Hornik (

WU Wirtschaftsuniversität Wien, Austria


1 R 4.2.0 selected changes

R 4.2.0 (codename “Vigorous Calisthenics”) was released on 2022-04-22. The December 2021 (13/2) issue of the R Journal provided a selection of the most important changes in that release that were already settled at that time, including:

A selection of the remaining important R 4.2.0 changes is provided here.

2 R 4.2.1 and R-patched changes on Windows

R 4.2.0 on Windows switched to UTF-8 as the native encoding and to UCRT as the Windows runtime. R is an early adopter of UCRT in the open-source community of projects compiled using free and open-source compilers, and particularly an early adopter of UTF-8 as the native encoding on Windows, hence this came with considerable effort and risk of bugs. Hence, testing using CRAN package checks has been in place for over a year before the release (and 9 months of that time in parallel to the usual CRAN checks when R-devel still used MSVCRT as the C runtime).

Still, some issues not covered by such tests, mostly in interactive use and Rgui, have been reported by users after the 4.2 release and have been fixed in R-patched. R users on Windows should update to the latest available patch version.

Selected fixes in R 4.2.1:

Selected fixes in R-patched, to become R 4.2.2:

The bug reports have revealed that Rgui is frequently used, including by users with visual or hand impairments who find Rgui working well with assistive technologies.

The bugs were fixed promptly in R-patched. Impacted users may install a snapshot of R-patched in case waiting for the next release would be too limiting.

3 R 4.2.0 code statistics

From the source code Subversion repository, the overall change between May 18, 2021 and April 22, 2022 (so between R 4.1.0 and R 4.2.0) was: 29,000 added lines, 20,000 deleted lines and 900 changed files. This is rounded to thousands/hundreds and excludes changes to common generated files, bulk re-organizations, etc. (translations, parsers, Autoconf, LAPACK, R Journal bibliography, test outputs, Unicode tables, incorporated M4 macros, BLAS, KaTeX files). This is about 10% fewer additions and changed files and about 43% more deletions than between R 4.0.0 and R 4.1.0, see News and Notes from the June 2021 issue of the R Journal.

Figure 1 shows commits by month and weekday, respectively, counting line-based changes in individual commits, excluding the files as above. The statistics are computed the same way as in the June 2021 issue, hence allowing direct comparisons. However, monthly statistics are impacted by the release date which varies across versions, so the numbers for April and May are somewhat biased. The statistics cover code directly committed to the trunk, plus commits from the merged branches R-groups, R-vecpat. R-ucrt and R-structure. Statistics are based on the dates of the original commits in the branches, which includes commits from April 2021 (R-groups).

graphic without alt textgraphic without alt text

Figure 1: Commit statistics by month (left) and weekday (right) during R 4.2.0 development. *Counts for April 2021 represent early work on the R-groups branch. May 2021 and April 2022 are partial months impacted by the release dates.

4 Acknowledgements

Tomas Kalibera’s work on the article and R development has received funding from the Czech Ministry of Education, Youth and Sports from the Czech Operational Programme Research, Development, and Education, under grant agreement No.CZ.02.1.01/0.0/0.0/15_003/0000421, from the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme, under grant agreement No. 695412, and from the National Science Foundation award 1925644.

CRAN packages used

knitr, rJava

CRAN Task Views implied by cited packages

HighPerformanceComputing, ReproducibleResearch


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For attribution, please cite this work as

Kalibera, et al., "Changes in R", The R Journal, 2022

BibTeX citation

  author = {Kalibera, Tomas and Meyer, Sebastian and Hornik, Kurt},
  title = {Changes in R},
  journal = {The R Journal},
  year = {2022},
  note = {},
  volume = {14},
  issue = {2},
  issn = {2073-4859},
  pages = {336-338}