R News

CHANGES IN R 4.1.0:

  FUTURE DIRECTIONS:

It is planned that the 4.1.x series will be the last to support 32-bit
      Windows, with production of binary packages for that series
      continuing until early 2023.

  SIGNIFICANT USER-VISIBLE CHANGES:

Data set esoph in package datasets now provides the correct numbers of
      controls; previously it had the numbers of cases added to these.
      (Reported by Alexander Fowler in PR#17964.)

  NEW FEATURES:

www.omegahat.net is no longer one of the repositories known by default
      to setRepositories().  (Nowadays it only provides source packages
      and is often unavailable.)

Function package_dependencies() (in package tools) can now use
      different dependency types for direct and recursive dependencies.

The checking of the size of tarball in R CMD check --as-cran <pkg> may
      be tweaked via the new environment variable
      _R_CHECK_CRAN_INCOMING_TARBALL_THRESHOLD_, as suggested in
      PR#17777 by Jan Gorecki.

Using c() to combine a factor with other factors now gives a factor, an
      ordered factor when combining ordered factors with identical
      levels.

apply() gains a simplify argument to allow disabling of simplification
      of results.

The format() method for class "ftable" gets a new option justify.
      (Suggested by Thomas Soeiro.)

New ...names() utility.  (Proposed by Neal Fultz in PR#17705.)

type.convert() now warns when its as.is argument is not specified, as
      the help file always said it _should_.  In that case, the default
      is changed to TRUE in line with its change in read.table()
      (related to stringsAsFactor) in R 4.0.0.

When printing list arrays, classed objects are now shown _via_ their
      format() value if this is a short enough character string, or by
      giving the first elements of their class vector and their length.

capabilities() gets new entry "Rprof" which is TRUE when R has been
      configured with the equivalent of --enable-R-profiling (as it is
      by default).  (Related to Michael Orlitzky's report PR#17836.)

str(xS4) now also shows extraneous attributes of an S4 object xS4.

Rudimentary support for vi-style tags in rtags() and R CMD rtags has
      been added.  (Based on a patch from Neal Fultz in PR#17214.)

checkRdContents() is now exported from tools; it and also
      checkDocFiles() have a new option chkInternal allowing to check
      Rd files marked with keyword "internal" as well.  The latter can
      be activated for R CMD check via environment variable
      _R_CHECK_RD_INTERNAL_TOO_.

New functions numToBits() and numToInts() extend the raw conversion
      utilities to (double precision) numeric.

Functions URLencode() and URLdecode() in package utils now work on
      vectors of URIs.  (Based on patch from Bob Rudis submitted with
      PR#17873.)

path.expand() can expand ~user on most Unix-alikes even when readline
      is not in use.  It tries harder to expand ~, for example should
      environment variable HOME be unset.

For HTML help (both dynamic and static), Rd file links to help pages in
      external packages are now treated as references to topics rather
      than file names, and fall back to a file link only if the topic
      is not found in the target package. The earlier rule which
      prioritized file names over topics can be restored by setting the
      environment variable _R_HELP_LINKS_TO_TOPICS_ to a false value.

c() now removes NULL arguments before dispatching to methods, thus
      simplifying the implementation of c() methods, _but_ for back
      compatibility keeps NULL when it is the first argument.  (From a
      report and patch proposal by Lionel Henry in PR#17900.)

Vectorize()'s result function's environment no longer keeps unneeded
      objects.

Function ...elt() now propagates visibility consistently with ..n.
      (Thanks to Lionel Henry's PR#17905.)

capture.output() no longer uses non-standard evaluation to evaluate its
      arguments.  This makes evaluation of functions like
      parent.frame() more consistent.  (Thanks to Lionel Henry's
      PR#17907.)

packBits(bits, type="double") now works as inverse of numToBits().
      (Thanks to Bill Dunlap's proposal in PR#17914.)

curlGetHeaders() has two new arguments, timeout to specify the timeout
      for that call (overriding getOption("timeout")) and TLS to
      specify the minimum TLS protocol version to be used for https://
      URIs (_inter alia_ providing a means to check for sites using
      deprecated TLS versions 1.0 and 1.1).

For nls(), an optional constant scaleOffset may be added to the
      denominator of the relative offset convergence test for cases
      where the fit of a model is expected to be exact, thanks to a
      proposal by John Nash.  nls(*, trace=TRUE) now also shows the
      convergence criterion.

Numeric differentiation _via_ numericDeriv() gets new optional
      arguments eps and central, the latter for taking central divided
      differences.  The latter can be activated for nls() via
      nls.control(nDcentral = TRUE).

nls() now passes the trace and control arguments to getInitial(),
      notably for all self-starting models, so these can also be fit in
      zero-noise situations via a scaleOffset.  For this reason, the
      initial function of a selfStart model must now have ... in its
      argument list.

bquote(splice = TRUE) can now splice expression vectors with
      attributes: this makes it possible to splice the result of
      parse(keep.source = TRUE).  (Report and patch provided by Lionel
      Henry in PR#17869.)

textConnection() gets an optional name argument.

get(), exists(), and get0() now signal an error if the first argument
      has length greater than 1.  Previously additional elements were
      silently ignored.  (Suggested by Antoine Fabri on R-devel.)

R now provides a shorthand notation for creating functions, e.g. \(x) x
      + 1 is parsed as function(x) x + 1.

R now provides a simple native forward pipe syntax |>.  The simple form
      of the forward pipe inserts the left-hand side as the first
      argument in the right-hand side call.  The pipe implementation as
      a syntax transformation was motivated by suggestions from Jim
      Hester and Lionel Henry.

all.equal(f, g) for functions now by default also compares their
      environment(.)s, notably via new all.equal method for class
      function.  Comparison of nls() fits, e.g., may now need
      all.equal(m1, m2, check.environment = FALSE).

.libPaths() gets a new option include.site, allowing to _not_ include
      the site library.  (Thanks to Dario Strbenac's suggestion and
      Gabe Becker's PR#18016.)

Lithuanian translations are now available.  (Thanks to

names() now works for DOTSXP objects.  On the other hand, in R-lang,
      the R language manual, we now warn against relying on the
      structure or even existence of such dot-dot-dot objects.

all.equal() no longer gives an error on DOTSXP objects.

capabilities("cairo") now applies only to the file-based devices as it
      is now possible (if very unusual) to build R with Cairo support
      for those but not for X11().

There is optional support for tracing the progress of loadNamespace() -
      see its help.

(Not Windows.)  l10n_info() reports an additional element, the name of
      the encoding as reported by the OS (which may differ from the
      encoding part (if any) of the result from
      Sys.getlocale("LC_CTYPE").

New function gregexec() which generalizes regexec() to find _all_
      disjoint matches and well as all substrings corresponding to
      parenthesized subexpressions of the given regular expression.
      (Contributed by Brodie Gaslam.)

New function charClass() in package utils to query the wide-character
      classification functions in use (such as iswprint).

The names of quantile()'s result no longer depend on the global
      getOption("digits"), but quantile() gets a new optional argument
      digits = 7 instead.

grep(), sub(), regexp and variants work considerably faster for long
      factors with few levels.  (Thanks to Michael Chirico's PR#18063.)

Provide grouping of x11() graphics windows within a window manager such
      as Gnome or Unity; thanks to a patch by Ivan Krylov posted to
      R-devel.

The split() method for class data.frame now allows the f argument to be
      specified as a formula.

sprintf now warns on arguments unused by the format string.

New palettes "Rocket" and "Mako" for hcl.colors() (approximating
      palettes of the same name from the 'viridisLite' package).

      Contributed by Achim Zeileis.

The base environment and its namespace are now locked (so one can no
      longer add bindings to these or remove from these).

Rterm handling of multi-byte characters has been improved, allowing use
      of such characters when supported by the current locale.

Rterm now accepts ALT+ +xxxxxxxx sequences to enter Unicode characters
      as hex digits.

Environment variable LC_ALL on Windows now takes precedence over
      LC_CTYPE and variables for other supported categories, matching
      the POSIX behaviour.

duplicated() and anyDuplicated() are now optimized for integer and real
      vectors that are known to be sorted via the ALTREP framework.
      Contributed by Gabriel Becker via PR#17993.

  GRAPHICS:

The graphics engine version, R_GE_version, has been bumped to 14 and so
      packages that provide graphics devices should be reinstalled.

Graphics devices should now specify deviceVersion to indicate what
      version of the graphics engine they support.

Graphics devices can now specify deviceClip.  If TRUE, the graphics
      engine will never perform any clipping of output itself.

      The clipping that the graphics engine does perform (for both
      canClip = TRUE and canClip = FALSE) has been improved to avoid
      producing unnecessary artifacts in clipped output.

The grid package now allows gpar(fill) to be a linearGradient(), a
      radialGradient(), or a pattern().  The viewport(clip) can now
      also be a grob, which defines a clipping path, and there is a new
      viewport(mask) that can also be a grob, which defines a mask.

      These new features are only supported so far on the Cairo-based
      graphics devices and on the pdf() device.

(Not Windows.)  A warning is given when a Cairo-based type is specified
      for a png(), jpeg(), tiff() or bmp() device but Cairo is
      unsupported (so type = "Xlib" is tried instead).

grSoftVersion() now reports the versions of FreeType and FontConfig if
      they are used directly (not _via_ Pango), as is most commonly
      done on macOS.

  C-LEVEL FACILITIES:

The _standalone_ libRmath math library and R's C API now provide
      log1pexp() again as documented, and gain log1mexp().

  INSTALLATION on a UNIX-ALIKE:

configure checks for a program pkgconf if program pkg-config is not
      found.  These are now only looked for on the path (like almost
      all other programs) so if needed specify a full path to the
      command in PKG_CONFIG, for example in file config.site.

C99 function iswblank is required - it was last seen missing ca 2003 so
      the workaround has been removed.

There are new configure options --with-internal-iswxxxxx,
      --with-internal-towlower and --with-internal-wcwidth which allows
      the system functions for wide-character classification,
      case-switching and width (wcwidth and wcswidth) to be replaced by
      internal ones.  The first has long been used on macOS, AIX (and
      Windows) but this enables it to be unselected there and selected
      for other platforms (it is the new default on Solaris).  The
      second is new in this version of R and is selected by default on
      macOS and Solaris.  The third has long been the default and
      remains so as it contains customizations for East Asian
      languages.

      System versions of these functions are often minimally
      implemented (sometimes only for ASCII characters) and may not
      cover the full range of Unicode points: for example Solaris (and
      Windows) only cover the Basic Multilingual Plane.

Cairo installations without X11 are more likely to be detected by
      configure, when the file-based Cairo graphics devices will be
      available but not X11(type = "cairo").

There is a new configure option --with-static-cairo which is the
      default on macOS.  This should be used when only static cairo
      (and where relevant, Pango) libraries are available.

Cairo-based graphics devices on platforms without Pango but with
      FreeType/FontConfig will make use of the latter for font
      selection.

  LINK-TIME OPTIMIZATION on a UNIX-ALIKE:

Configuring with flag --enable-lto=R now also uses LTO when installing
      the recommended packages.

R CMD INSTALL and R CMD SHLIB have a new flag --use-LTO to use LTO when
      compiling code, for use with R configured with --enable-lto=R.
      For R configured with --enable-lto, they have the new flag
      --no-use-LTO.

      Packages can opt in or out of LTO compilation _via_ a UseLTO
      field in the DESCRIPTION file.  (As usual this can be overridden
      by the command-line flags.)

  BUILDING R on Windows:

for GCC >= 8, FC_LEN_T is defined in config.h and hence character
      lengths are passed from C to Fortran in _inter alia_ BLAS and
      LAPACK calls.

There is a new text file src/gnuwin32/README.compilation, which
      outlines how C/Fortran code compilation is organized and
      documents new features:

R can be built with Link-Time Optimization with a suitable compiler -
          doing so with GCC 9.2 showed several inconsistencies which
          have been corrected.

There is support for cross-compiling the C and Fortran code in R and
          standard packages on suitable (Linux) platforms.  This is
          mainly intended to allow developers to test later versions of
          compilers - for example using GCC 9.2 or 10.x has detected
          issues that GCC 8.3 in Rtools40 does not.

There is experimental support for cross-building R packages with C, C++
          and/or Fortran code.

The R installer can now be optionally built to support a single
      architecture (only 64-bit or only 32-bit).

  PACKAGE INSTALLATION:



           Depends: R (>= 3.4)
      
  PACKAGE INSTALLATION on Windows:



  PACKAGE INSTALLATION on macOS:

The default personal library directory on builds with --enable-aqua
      (including CRAN builds) now differs by CPU type, one of

            ~/Library/R/x86_64/x.y/library
            ~/Library/R/arm64/x.y/library
      
      This uses the CPU type R (and hence the packages) were built for,
      so when a x86_64 build of R is run under Rosetta emulation on an
      arm64 Mac, the first is used.

  UTILITIES:

R CMD check can now scan package functions for bogus return statements,
      which were possibly intended as return() calls (wish of PR#17180,
      patch by Sebastian Meyer). This check can be activated via the
      new environment variable _R_CHECK_BOGUS_RETURN_, true for
      --as-cran.

R CMD build omits tarballs and binaries of previous builds from the
      top-level package directory.  (PR#17828, patch by Sebastian
      Meyer.)



R CMD build removes LazyData and LazyDataCompression fields from the
      DESCRIPTION file of packages without a data directory.

  ENCODING-RELATED CHANGES:

The parser now treats \Unnnnnnnn escapes larger than the upper limit
      for Unicode points (\U10FFFF) as an error as they cannot be
      represented by valid UTF-8.

      Where such escapes are used for outputting non-printable
      (including unassigned) characters, 6 hex digits are used (rather
      than 8 with leading zeros).  For clarity, braces are used, for
      example \U{0effff}.

The parser now looks for non-ASCII spaces on Solaris (as previously on
      most other OSes).

There are warnings (including from the parser) on the use of unpaired
      surrogate Unicode points such as \uD834.  (These cannot be
      converted to valid UTF-8.)

Functions nchar(), tolower(), toupper() and chartr() and those using
      regular expressions have more support for inputs with a marked
      Latin-1 encoding.

The character-classification functions used (by default) to replace the
      system iswxxxxx functions on Windows, macOS and AIX have been
      updated to Unicode 13.0.0.

      The character-width tables have been updated to include new
      assignments in Unicode 13.0.0.

The code for evaluating default (extended) regular expressions now uses
      the same character-classification functions as the rest of R
      (previously they differed on Windows, macOS and AIX).

There is a build-time option to replace the system's wide-character
      wctrans C function by tables shipped with R: use configure option
      --with-internal-towlower or (on Windows) -DUSE_RI18N_CASE in
      CFLAGS when building R.  This may be needed to allow tolower()
      and toupper() to work with Unicode characters beyond the Basic
      Multilingual Plane where not supported by system functions (e.g.
      on Solaris where it is the new default).

R is more careful when truncating UTF-8 and other multi-byte strings
      that are too long to be printed, passed to the system or
      libraries or placed into an internal buffer.  Truncation will no
      longer produce incomplete multibyte characters.

  DEPRECATED AND DEFUNCT:

Function plclust() from the package stats and package.dependencies(),
      pkgDepends(), getDepList(), installFoundDepends(), and
      vignetteDepends() from package tools are defunct.

Defunct functions checkNEWS() and readNEWS() from package tools and
      CRAN.packages() from utils have been removed.

R CMD config CXXCPP is defunct (it was deprecated in R 3.6.2).

parallel::detectCores() drops support for Irix (retired in 2013).

The LINPACK argument to chol.default(), chol2inv(), solve.default() and
      svd() has been defunct since R 3.1.0.  It was silently ignored up
      to R 4.0.3 but now gives an error.

Subsetting/indexing, such as ddd[*] or ddd$x on a DOTSXP (dot-dot-dot)
      object ddd has been disabled; it worked by accident only and was
      undocumented.

  BUG FIXES:

Many more C-level allocations (mainly by malloc and strdup) are checked
      for success with suitable alternative actions.

Bug fix for replayPlot(); this was turning off graphics engine display
      list recording if a recorded plot was replayed in the same
      session.  The impact of the bug became visible if resize the
      device after replay OR if attempted another savePlot() after
      replay (empty display list means empty screen on resize or empty
      saved plot).



boxplot() now also accepts calls for labels such as ylab, the same as
      plot().  (Reported by Marius Hofert.)

The help page for xtabs() now correctly states that addNA is setting
      na.action = na.pass among others.  (Reported as PR#17770 by
      Thomas Soeiro.)

The R CMD check <pkg> gives a longer and more comprehensible message
      when DESCRIPTION misses dependencies, e.g., in Imports:.  (Thanks
      to the contributors of PR#17179.)

update.default() now calls the generic update() on the formula to work
      correctly for models with extended formulas.  (As reported and
      suggested by Neal Fultz in PR#17865.)

The horizontal position of leaves in a dendrogram is now correct also
      with center = FALSE.  (PR#14938, patch from Sebastian Meyer.)

all.equal.POSIXt() no longer warns about and subsequently ignores
      inconsistent "tzone" attributes, but describes the difference in
      its return value (PR#17277).  This check can be disabled _via_
      the new argument check.tzone = FALSE as suggested by Sebastian
      Meyer.

as.POSIXct() now populates the "tzone" attribute from its tz argument
      when x is a logical vector consisting entirely of NA values.

x[[2^31]] <- v now works.  (Thanks to the report and patch by Suharto
      Anggono in PR#17330.)

In log-scale graphics, axis() ticks and label positions are now
      computed more carefully and symmetrically in their range,
      typically providing _more_ ticks, fulfilling wishes in PR#17936.
      The change really corresponds to an improved axisTicks() (package
      grDevices), potentially influencing grid and lattice, for
      example.

qnorm(<very large negative>, log.p=TRUE) is now correct to at least
      five digits where it was catastrophically wrong, previously.

sum(df) and similar "Summary"- and "Math"-group member functions now
      work for data frames df with logical columns, notably also of
      zero

unsplit() had trouble with tibbles due to unsound use of rep(NA,
      len)-indexing, which should use NA_integer_ (Reported to R-devel
      by Mario Annau.)

pnorm(x, log.p = TRUE) underflows to -Inf slightly later.

show(<hidden S4 generic>) prints better and without quotes for
      non-hidden S4 generics.

read.table() and relatives treated an "NA" column name as missing when
      check.names = FALSE PR#18007.

Parsing strings containing UTF-16 surrogate pairs such as
      "\uD834\uDD1E" works better on some (uncommon) platforms.
      sprintf("%X", utf8ToInt("\uD834\uDD1E")) should now give "1D11E"
      on all platforms.

identical(x,y) is no longer true for differing DOTSXP objects, fixing
      PR#18032.



Too long lines in environment files (e.g. Renviron) no longer crash R.
      This limit has been increased to 100,000 bytes.  (PR#18001.)

There is a further workaround for FreeType giving incorrect italic font
      faces with cairo-based graphics devices on macOS.

add_datalist(*, force = TRUE) (from package tools) now actually updates
      an existing data/datalist file for new content.  (Thanks to a
      report and patch by Sebastian Meyer in PR#18048.)

cut.Date() and cut.POSIXt() could produce an empty last interval for
      breaks = "months" or breaks = "years".  (Reported as PR#18053 by
      Christopher Carbone.)



sub() and gsub(pattern, repl, x, *) now keep attributes of x such as
      names() also when pattern is NA (PR#18079).

Time differences ("difftime" objects) get a replacement and a rep()
      method to keep "units" consistent.  (Thanks to a report and patch
      by Nicolas Bennett in PR#18066.)

The \RdOpts macro, setting defaults for \Sexpr options in an Rd file,
      had been ineffective since R 2.12.0: it now works again.  (Thanks
      to a report and patch by Sebastian Meyer in PR#18073.)

mclapply and pvec no longer accidentally terminate parallel processes
      started before by mcparallel or related calls in package parallel
      (PR#18078).

grep and other functions for evaluating (extended) regular expressions
      handle in Unicode also strings not explicitly flagged UTF-8, but
      flagged native when running in UTF-8 locale.

Fixed a crash in fifo implementation on Windows (PR#18031).

Binary mode in fifo on Windows is now properly detected from argument
      open (PR#15600, PR#18031).

CHANGES IN R 4.0.5:

  BUG FIXES:

The change to the internal table in R 4.0.4 for iswprint has been
      reverted: it contained some errors in

For packages using LazyData, R CMD build ignored the --resave-data
      option and the BuildResaveData field of the DESCRIPTION file (in
      R versions 4.0.0 to 4.0.4).

CHANGES IN R 4.0.4:

  NEW FEATURES:

File share/texmf/tex/latex/jss.cls has been updated to work with LaTeX
      versions since Oct 2020.

Unicode character width tables (as used by nchar(, type = "w")) have
      been updated to Unicode 12.1 by Brodie Gaslam (PR#17781),
      including many emoji.

The internal table for iswprint (used on Windows, macOS and AIX) has
      been updated to include many recent Unicode characters.

  INSTALLATION on a UNIX-ALIKE:

If an external BLAS is specified by --with-blas=foo or _via_
      environment variable BLAS_LIBS is not found, this is now a
      configuration error.  The previous behaviour was not clear from
      the documentation: it was to continue the search as if
      --with-blas=yes was specified.

  BUG FIXES:



(~ NULL)[1] and similar formula subsetting now works, thanks to a
      report and patch by Henrik Bengtsson in PR#17935.  Additionally,
      subsetting leaving an empty formula now works too, thanks to
      suggestions by Suharto Anggono.

.traceback(n) keeps source references again, as before R 4.0.0, fixing
      a regression; introduced by the PR#17580, reported including two
      patch proposals by Brodie Gaslam.

unlist(plst, recursive=FALSE) no longer drops content for pairlists
      with list components, thanks to the report and patch by Suharto
      Anggono in PR#17950.

iconvlist() now also works on MUSL based (Linux) systems, from a report
      and patch suggestion by Wesley Chan in PR#17970.

round() and signif() no longer tolerate wrong argument names, notably
      in 1-argument calls; reported by Shane Mueller on R-devel
      (mailing list); later reported as PR#17976.

.Machine has longdouble.* elements only if capabilities("long.double")
      is true, as documented.  (Previously they were included if the
      platform had long double identical to double, as ARM does.)

p.adjust(numeric(), n=0) now works, fixing PR#18002.

identical(x,y) no longer prints "Unknown Type .." for typeof(x) ==
      "..." objects.

Fix (auto-)print()ing of named complex vectors, see PR#17868 and
      PR#18019.

all.equal(<language>, <...>) now works, fixing PR#18029.

as.data.frame.list(L, row.names=NULL) now behaves in line with
      data.frame(), disregarding names of components of L, fixing
      PR#18034, reported by Kevin Tappe.

checkRdaFiles(ff)$version is now correct also when ff contains files of
      different versions, thanks to a report and patch from Sebastian
      Meyer in PR#18041.



macOS: Quartz device live drawing could fail (no plot is shown) if the
      system changes the drawing context after view update (often the
      case since macOS Big Sur). System log may show
      "CGContextDelegateCreateForContext: invalid context" error.

CHANGES IN R 4.0.3:

  NEW FEATURES:

On platforms using configure option --with-internal-tzcode, additional
      values "internal" and (on macOS only) "macOS" are accepted for
      the environment variable TZDIR.  (See ?TZDIR.)

      On macOS, "macOS" is used by default if the system timezone
      database is a newer version than that in the R installation.

When install.packages(type = "source") fails to find a package in a
      repository it mentions package versions which are excluded by
      their R version requirement and links to hints on why a package
      might not be found.

The default value for options("timeout") can be set from environment
      variable R_DEFAULT_INTERNET_TIMEOUT, still defaulting to 60
      (seconds) if that is not set or invalid.

      This may be needed when child R processes are doing downloads,
      for example during the installation of source packages which
      download jars or other forms of data.

  LINK-TIME OPTIMIZATION on a UNIX-ALIKE:



There is support for setting a different LTO flag for the Fortran
      compiler, including to empty when mixing clang and gfortran (as
      on macOS).  See file config.site.

There is a new LTO_LD macro to set linker options for LTO compilation,
      for example to select an alternative linker or to parallelize
      thin LTO.

  DEPRECATED AND DEFUNCT:

The LINPACK argument to chol.default(), chol2inv(), solve.default() and
      svd() has been defunct since R 3.1.0.  Using it now gives a
      warning which will become an error in R 4.1.0.

  BUG FIXES:

The code mitigating stack overflow with PCRE regexps on very long
      strings is enabled for PCRE2 < 10.30 also when JIT is enabled,
      since stack overflows have been seen in that case.

Fix to correctly show the group labels in dotchart() (which where lost
      in the ylab improvement for R 4.0.0).

addmargins(*, ..) now also works when fn() is a local function, thanks
      to bug report and patch PR#17124 from Alex Bertram.

rank(x) and hence sort(x) now work when x is an object (as per
      is.object(x)) of type "raw" _and_ provides a valid `[` method,
      e.g., for gmp::as.bigz(.) numbers.

chisq.test(*, simulate.p.value=TRUE) and r2dtable() now work correctly
      for large table entries (in the millions).  Reported by Sebastian
      Meyer and investigated by more helpers in PR#16184.

Low-level socket read/write operations have been fixed to correctly
      signal communication errors. Previously, such errors could lead
      to a segfault due to invalid memory access. Reported and debugged
      by Dmitriy Selivanov in PR#17850.

quantile(x, pr) works more consistently for pr values slightly outside
      [0,1], thanks to Suharto Anggono's PR#17891.

      Further, quantile(x, prN, names=FALSE) now works even when prN
      contains NAs, thanks to Anggono's PR#17892.  Ditto for ordered
      factors or Date objects when type = 1 or 3, thanks to PR#17899.

Libcurl-based internet access, including curlGetHeaders(), was not
      respecting the "timeout" option.  If this causes unanticipated
      timeouts, consider increasing the default by setting
      R_DEFAULT_INTERNET_TIMEOUT.

as.Date(<char>) now also works with an initial "", thanks to Michael
      Chirico's PR#17909.

isS3stdGeneric(f) now detects an S3 generic also when it it is
      trace()d, thanks to Gabe Becker's PR#17917.

R_allocLD() has been fixed to return memory aligned for long double
      type PR#16534.

fisher.test() no longer segfaults when called again after its internal
      stack has been exceeded PR#17904.

Accessing a long vector represented by a compact integer sequence no
      longer segfaults (reported and debugged by Hugh Parsonage).

duplicated() now works also for strings with multiple encodings inside
      a single vector PR#17809.

phyper(11, 15, 0, 12, log.p=TRUE) no longer gives NaN; reported as
      PR#17271 by Alexey Stukalov.

Fix incorrect calculation in logLik.nls() PR#16100, patch from
      Sebastian Meyer.

A very old bug could cause a segfault in model.matrix() when terms
      involved logical variables.  Part of PR#17879.

model.frame.default() allowed data = 1, leading to involuntary variable
      capture (rest of PR#17879).

tar() no longer skips non-directory files, thanks to a patch by
      Sebastian Meyer, fixing the remaining part of PR#16716.

CHANGES IN R 4.0.2:

  UTILITIES:

R CMD check skips vignette re-building (with a warning) if the
      VignetteBuilder package(s) are not available.

  BUG FIXES:

Paths with non-ASCII characters caused problems for package loading on
      Windows PR#17833.

Using tcltk widgets no longer crashes R on Windows.

source(*, echo=TRUE) no longer fails in some cases with empty lines;
      reported by Bill Dunlap in PR#17769.

on.exit() now correctly matches named arguments, thanks to PR#17815
      (including patch) by Brodie Gaslam.

regexpr(*, perl=TRUE) no longer returns incorrect positions into text
      containing characters outside of the Unicode Basic Multilingual
      Plane on Windows.

CHANGES IN R 4.0.1:

  NEW FEATURES:

paste() and paste0() gain a new optional argument recycle0.  When set
      to true, zero-length arguments are recycled leading to
      character(0) after the sep-concatenation, i.e., to the empty
      string "" if collapse is a string and to the zero-length value
      character(0) when collapse = NULL.

      A package whose code uses this should depend on R (>= 4.0.1).

The summary(<warnings>) method now maps the counts correctly to the
      warning messages.

  BUG FIXES:

aov(frml, ...) now also works where the formula deparses to more than
      500 characters, thanks to a report and patch proposal by Jan
      Hauffa.

Fix a dozen places (code, examples) as Sys.setlocale() returns the new
      rather than the previous setting.

Fix for adding two complex grid units via sum().  Thanks to Gu Zuguang
      for the report and Thomas Lin Pedersen for the patch.

Fix parallel::mclapply(..., mc.preschedule=FALSE) to handle raw vector
      results correctly. PR#17779



In R 4.0.0, sort.list(x) when is.object(x) was true, e.g., for x <-
      I(letters), was accidentally using method = "radix".
      Consequently, e.g., merge(<data.frame>) was much slower than
      previously; reported in PR#17794.

plot(y ~ x, ylab = quote(y[i])) now works, as e.g., for xlab; related
      to PR#10525.

parallel::detect.cores(all.tests = TRUE) tries a matching OS name
      before the other tests (which were intended only for unknown
      OSes).

Parse data for raw strings is now recorded correctly. Reported by Gabor
      Csardi.

CHANGES IN R 4.0.0:

  SIGNIFICANT USER-VISIBLE CHANGES:

Packages need to be (re-)installed under this version (4.0.0) of R.

matrix objects now also inherit from class "array", so e.g.,
      class(diag(1)) is c("matrix", "array").  This invalidates code
      incorrectly assuming that class(matrix_obj)) has length one.

      S3 methods for class "array" are now dispatched for matrix
      objects.

There is a new syntax for specifying _raw_ character constants similar
      to the one used in C++: r"(...)" with ... any character sequence
      not containing the sequence )".  This makes it easier to write
      strings that contain backslashes or both single and double
      quotes.  For more details see ?Quotes.

R now uses a stringsAsFactors = FALSE default, and hence by default no
      longer converts strings to factors in calls to data.frame() and
      read.table().

      A large number of packages relied on the previous behaviour and
      so have needed/will need updating.

The plot() S3 generic function is now in package base rather than
      package graphics, as it is reasonable to have methods that do not
      use the graphics package.  The generic is currently re-exported
      from the graphics namespace to allow packages importing it from
      there to continue working, but this may change in future.

      Packages which define S4 generics for plot() should be
      re-installed and package code using such generics from other
      packages needs to ensure that they are imported rather than rely
      on their being looked for on the search path (as in a namespace,
      the base namespace has precedence over the search path).

  REFERENCE COUNTING:

Reference counting is now used instead of the NAMED mechanism for
      determining when objects can be safely mutated in base C code.
      This reduces the need for copying in some cases and should allow
      further optimizations in the future.  It should help make the
      internal code easier to maintain.

      This change is expected to have almost no impact on packages
      using supported coding practices in their C/C++ code.

  MIGRATION TO PCRE2:

This version of R is built against the PCRE2 library for Perl-like
      regular expressions, if available.  (On non-Windows platforms
      PCRE1 can optionally be used if PCRE2 is not available at build
      time.)  The version of PCRE in use can be obtained _via_
      extSoftVersion(): PCRE1 (formerly known as

Making PCRE2 available when building R from source is strongly
      recommended (preferably version 10.30 or later) as PCRE1 is no
      longer developed: version 8.44 is

PCRE2 reports errors for some regular expressions that were accepted by
      PCRE1.  A hyphen now has to be escaped in a character class to be
      interpreted as a literal (unless first or last in the class
      definition).  \R, \B and \X are no longer allowed in character
      classes (PCRE1 treated these as literals).

Option PCRE_study is no longer used with PCRE2, and is reported as
      FALSE when that is in use.

  NEW FEATURES:

assertError() and assertWarning() (in package tools) can now check for
      _specific_ error or warning classes _via_ the new optional second
      argument classes (which is not back compatible with previous use
      of an unnamed second argument).

DF2formula(), the utility for the data frame method of formula(), now
      works without parsing and explicit evaluation, starting from
      Suharto Anggono's suggestion in PR#17555.

approxfun() and approx() gain a new argument na.rm defaulting to true.
      If set to false, missing y values now propagate into the
      interpolated values.

Long vectors are now supported as the seq argument of a for() loop.

str(x) gets a new deparse.lines option with a default to speed it up
      when x is a large call object.

The internal traceback object produced when an error is signalled
      (.Traceback), now contains the calls rather than the _deparse()d_
      calls, deferring the deparsing to the user-level functions
      .traceback() and traceback().  This fulfils the wish of PR#17580,
      reported including two patch proposals by Brodie Gaslam.

data.matrix() now converts character columns to factors and from this
      to integers.

package.skeleton() now explicitly lists all exports in the NAMESPACE
      file.

New function .S3method() to register S3 methods in R scripts.

file.path() has some support for file paths not in the session
      encoding, e.g. with UTF-8 inputs in a non-UTF-8 locale the output
      is marked as UTF-8.

Most functions with file-path inputs will give an explicit error if a
      file-path input in a marked encoding cannot be translated (to the
      native encoding or in some cases on Windows to UTF-8), rather
      than translate to a different file path using escapes.  Some
      (such as dir.exists(), file.exists(), file.access(), file.info(),
      list.files(), normalizePath() and path.expand()) treat this like
      any other non-existent file, often with a warning.

There is a new help document accessed by help("file path encoding")
      detailing how file paths with marked encodings are handled.

New function list2DF() for creating data frames from lists of
      variables.

iconv() has a new option sub = "Unicode" to translate UTF-8 input
      invalid in the to encoding using <U+xxxx> escapes.

There is a new function infoRDS() providing information about the
      serialization format of a serialized object.

S3 method lookup now by default skips the elements of the search path
      between the global and base environments.

Added an argument add_datalist(*, small.size = 0) to allow the creation
      of a data/datalist file even when the total size of the data sets
      is small.

The backquote function bquote() has a new argument splice to enable
      splicing a computed list of values into an expression, like ,@ in
      LISP's backquote.

The formula interface to t.test() and wilcox.test() has been extended
      to handle one-sample and paired tests.

The palette() function has a new default set of colours (which are less
      saturated and have better accessibility properties).  There are
      also some new built-in palettes, which are listed by the new
      palette.pals() function.  These include the old default palette
      under the name "R3". Finally, the new palette.colors() function
      allows a subset of colours to be selected from any of the
      built-in palettes.

n2mfrow() gains an option asp = 1 to specify the aspect ratio,
      fulfilling the wish and extending the proposal of Michael Chirico
      in PR#17648.



New function .class2() provides the full character vector of class
      names used for S3 method dispatch.

Printing methods(..) now uses a new format() method.

sort.list(x) now works for non-atomic objects x and method = "auto"
      (the default) or "radix" in cases order(x) works, typically via a
      xtfrm() method.

Where they are available, writeBin() allows long vectors.

New function deparse1() produces one string, wrapping deparse(), to be
      used typically in deparse1(substitute(*)), e.g., to fix PR#17671.

wilcox.test() enhancements: In the (non-paired) two-sample case, Inf
      values are treated as very large for robustness consistency.  If
      exact computations are used, the result now has "exact" in the
      method element of its return value.  New arguments tol.root and
      digits.rank where the latter may be used for stability to treat
      very close numbers as ties.

readBin() and writeBin() now report an error for an invalid endian
      value.  The affected code needs to be fixed with care as the old
      undocumented behavior was to swap endian-ness in such cases.

sequence() is now an S3 generic with an internally implemented default
      method, and gains arguments to generate more complex sequences.
      Based on code from the S4Vectors

print()'s default method and many other methods (by calling the default
      eventually and passing ...) now make use of a new optional width
      argument, avoiding the need for the user to set and reset
      options("width").

memDecompress() supports the RFC 1952 format (e.g. in-memory copies of
      gzip-compressed files) as well as RFC 1950.

memCompress() and memDecompress() support long raw vectors for types
      "gzip" and "zx".

sweep() and slice.index() can now use names of dimnames for their
      MARGIN argument (apply has had this for almost a decade).

New function proportions() and marginSums(). These should replace the
      unfortunately named prop.table() and margin.table(). They are
      drop-in replacements, but also add named-margin functionality.
      The old function names are retained as aliases for
      back-compatibility.

Functions rbinom(), rgeom(), rhyper(), rpois(), rnbinom(), rsignrank()
      and rwilcox() which have returned integer since R 3.0.0 and hence
      NA when the numbers would have been outside the integer range,
      now return double vectors (without NAs, typically) in these
      cases.

matplot(x,y) (and hence matlines() and matpoints()) now call the
      corresponding methods of plot() and lines(), e.g, when x is a
      "Date" or "POSIXct" object; prompted by Spencer Graves'
      suggestion.

stopifnot() now allows customizing error messages via argument names,
      thanks to a patch proposal by Neal Fultz in PR#17688.

unlink() gains a new argument expand to disable wildcard and tilde
      expansion.  Elements of x of value "~" are now ignored.

mle() in the stats4 package has had its interface extended so that
      arguments to the negative log-likelihood function can be one or
      more vectors, with similar conventions applying to bounds, start
      values, and parameter values to be kept fixed.  This required a
      minor extension to class "mle", so saved objects from earlier
      versions may need to be recomputed.

The default for pdf() is now useDingbats = FALSE.

The default fill colour for hist() and boxplot() is now col =
      "lightgray".

The default order of the levels on the y-axis for spineplot() and
      cdplot() has been reversed.

If the R_ALWAYS_INSTALL_TESTS environment variable is set to a true
      value, R CMD INSTALL behaves as if the --install-tests option is
      always specified. Thanks to Reinhold Koch for the suggestion.

New function R_user_dir() in package tools suggests paths appropriate
      for storing R-related user-specific data, configuration and cache
      files.

capabilities() gains a new logical option Xchk to avoid warnings about
      X11-related capabilities.

The internal implementation of grid units has changed, but the only
      visible effects at user-level should be

a slightly different print format for some units (especially unit
          arithmetic),

faster performance (for unit operations) and

two new functions unitType() and unit.psum().

      Based on code contributed by Thomas Lin Pedersen.

When internal dispatch for rep.int() and rep_len() fails, there is an
      attempt to dispatch on the equivalent call to rep().

Object .Machine now contains new longdouble.* entries (when R uses long
      doubles internally).

news() has been enhanced to cover the news on R 3.x and 2.x.

For consistency, N <- NULL; N[[1]] <- val now turns N into a list also
      when val) has length one.  This enables dimnames(r1)[[1]] <- "R1"
      for a 1-row matrix r1, fixing PR#17719 reported by Serguei Sokol.

deparse(..), dump(..), and dput(x, control = "all") now include control
      option "digits17" which typically ensures 1:1 invertibility.  New
      option control = "exact" ensures numeric exact invertibility via
      "hexDigits".

When loading data sets via read.table(), data() now uses LC_COLLATE=C
      to ensure locale-independent results for possible
      string-to-factor conversions.

A server socket connection, a new connection type representing a
      listening server socket, is created via serverSocket() and can
      accept multiple socket connections via socketAccept().

New function socketTimeout() changes the connection timeout of a socket
      connection.

The time needed to start a homogeneous PSOCK cluster on localhost with
      many nodes has been significantly reduced (package parallel).

New globalCallingHandlers() function to establish global condition
      handlers.  This allows registering default handlers for specific
      condition classes. Developed in collaboration with Lionel Henry.

New function tryInvokeRestart() to invoke a specified restart if one is
      available and return without signaling an error if no such
      restart is found.  Contributed by Lionel Henry in PR#17598.

str(x) now shows the length of attributes in some cases for a data
      frame x.

Rprof() gains a new argument filter.callframes to request that
      intervening call frames due to lazy evaluation or explicit eval()
      calls be omitted from the recorded profile data.  Contributed by
      Lionel Henry in PR#17595.

The handling of ${FOO-bar} and ${FOO:-bar} in Renviron files now
      follows POSIX shells (at least on a Unix-alike), so the first
      treats empty environment variables as set and the second does
      not.  Previously both ignored empty variables.  There are several
      uses of the first form in etc/Renviron.

New classes argument for suppressWarnings() and suppressMessages() to
      selectively suppress only warnings or messages that inherit from
      particular classes.  Based on patch from Lionel Henry submitted
      with PR#17619.

New function activeBindingFunction() retrieves the function of an
      active binding.

New "cairoFT" and "pango" components in the output of grSoftVersion().

New argument symbolfamily in cairo-based graphics devices and new
      function cairoSymbolFont() that can be used to provide the value
      for that argument.

  Windows:

Rterm now works also when invoked from MSYS2 terminals.  Line editing
      is possible when command winpty is installed.

normalizePath() now resolves symbolic links and normalizes case of long
      names of path elements in case-insensitive folders (PR#17165).

md5sum() supports UTF-8 file names with characters that cannot be
      translated to the native encoding (PR#17633).

Rterm gains a new option --workspace to specify the workspace to be
      restored.  This allows equals to be part of the name when opening
      _via_ Windows file associations (reported by Christian Asseburg).

Rterm now accepts ALT+xxx sequences also with NumLock on.  Tilde can be
      pasted with an Italian keyboard (PR#17679).

R falls back to copying when junction creation fails during package
      checking (patch from Duncan Murdoch).

  DEPRECATED AND DEFUNCT:

Make macro F77_VISIBILITY has been removed and replaced by
      F_VISIBILITY.

Make macros F77, FCPIFCPLAGS and SHLIB_OPENMP_FCFLAGS have been removed
      and replaced by FC, FPICFLAGS and SHLIB_OPENMP_FFLAGS
      respectively.  (Most make programs will set F77 to the value of
      FC, which is set for package compilation.  But portable code
      should not rely on this.)

The deprecated support for specifying C++98 for package installation
      has been removed.

R CMD config no longer knows about the unused settings F77 and
      FCPIFCPLAGS, nor CXX98 and similar.

Either PCRE2 or PCRE1 >= 8.32 (Nov 2012) is required: the deprecated
      provision for 8.20-8.31 has been removed.

Defunct functions mem.limits(), .readRDS(),
      .saveRDS(),..find.package(), and .path.package() from package
      base and allGenerics(), getAccess(), getAllMethods(),
      getClassName(), getClassPackage(), getExtends(), getProperties(),
      getPrototype(), getSubclasses(), getVirtual(), mlistMetaName(),
      removeMethodsObject(), seemsS4Object(), traceOff(), and traceOn()
      from methods have been removed.

  C-LEVEL FACILITIES:

installChar is now remapped in Rinternals.h to installTrChar, of which
      it has been a wrapper since R 3.6.0.  Neither are part of the
      API, but packages using installChar can replace it if they depend
      on R >= 3.6.2.

Header R_ext/Print.h defines R_USE_C99_IN_CXX and hence exposes
      Rvprintf and REvprintf if used with a C++11 (or later) compiler.

There are new Fortran subroutines dblepr1, realpr1 and intpr1 to print
      a scalar variable (gfortran 10 enforces the distinction between
      scalars and length-one arrays).  Also labelpr to print just a
      label.

R_withCallingErrorHandler is now available for establishing a calling
      handler in C code for conditions inheriting from class error.

  INSTALLATION on a UNIX-ALIKE:

User-set DEFS (e.g., in config.site) is now used for compiling packages
      (including base packages).

There is a new variant option --enable-lto=check for checking
      consistency of BLAS/LAPACK/LINPACK calls - see

A C++ compiler default is set only if the C++11 standard is supported:
      it no longer falls back to C++98.

PCRE2 is used if available.  To make use of PCRE1 if PCRE2 is
      unavailable, configure with option --with-pcre1.

The minimum required version of libcurl is now 7.28.0 (Oct 2012).

New make target distcheck checks

R can be rebuilt from the tarball created by make dist,

the build from the tarball passes make check-all,

the build installs and uninstalls,

the source files are properly cleaned by make distclean.

  UTILITIES:

R --help now mentions the option --no-echo (renamed from --slave) and
      its previously undocumented short form -s.

R CMD check now optionally checks configure and cleanup scripts for

R CMD check --as-cran now runs \donttest examples (which are run by
      example()) instead of instructing the tester to do so.  This can
      be temporarily circumvented during development by setting
      environment variable _R_CHECK_DONTTEST_EXAMPLES_ to a false
      value.

  PACKAGE INSTALLATION:

There is the beginnings of support for the recently approved C++20
      standard, specified analogously to C++14 and C++17.  There is
      currently only limited support for this in compilers, with flags
      such as -std=c++20 and -std=c++2a.  For the time being the
      configure test is of accepting one of these flags and compiling
      C++17 code.

  BUG FIXES:



Long-standing issue where the X11 device could lose events shortly
      after startup has been addressed (PR#16702).

The data.frame method for rbind() no longer drops <NA> levels from
      factor columns by default (PR#17562).

available.packages() and hence install.packages() now pass their ...
      argument to download.file(), fulfilling the wish of PR#17532;
      subsequently, available.packages() gets new argument quiet,
      solving PR#17573.





format.default(*, scientific = FALSE) now corresponds to a practically
      most extreme options(scipen = n) setting rather than arbitrary n
      = 100.

format(as.symbol("foo")) now works (returning "foo").

postscript(.., title = *) now signals an error when the title string
      contains a character which would produce corrupt PostScript,
      thanks to PR#17607 by Daisuko Ogawa.

Certain Ops (notably comparison such as ==) now also work for 0-length
      data frames, after reports by Hilmar Berger.

methods(class = class(glm(..))) now warns more usefully and only once.

write.dcf() no longer mangles field names (PR#17589).

Primitive replacement functions no longer mutate a referenced first
      argument when used outside of a complex assignment context.

 A better error message for contour(*, levels = Inf).

The return value of contourLines() is no longer invisible().

The Fortran code for calculating the coefficients component in
      lm.influence() was very inefficient. It has (for now) been
      replaced with much faster R code (PR#17624).

cm.colors(n) _etc_ no longer append the code for alpha = 1, "FF", to
      all colors.  Hence all eight *.colors() functions and rainbow()
      behave consistently and have the same non-explicit default
      (PR#17659).

dnorm had a problematic corner case with sd == -Inf or negative sd
      which was not flagged as an error in all cases. Thanks to Stephen
      D. Weigand for reporting and Wang Jiefei for analyzing this;
      similar change has been made in dlnorm().

The optional iter.smooth argument of plot.lm(), (the plot() method for
      lm and glm fits) now defaults to 0 for all glm fits.  Especially
      for binary observations with high or low fitted probabilities,
      this effectively deleted all observations of 1 or 0.  Also, the
      type of residuals used in the glm case has been switched to
      "pearson" since deviance residuals do not in general have
      approximately zero mean.

In plot.lm, Cook's distance was computed from unweighted residuals,
      leading to inconsistencies.  Replaced with usual weighted
      version. (PR#16056)

Time-series ts(*, start, end, frequency) with fractional frequency are
      supported more consistently; thanks to a report from Johann
      Kleinbub and analysis and patch by Duncan Murdoch in PR#17669.

In case of errors mcmapply() now preserves attributes of returned
      "try-error" objects and avoids simplification, overriding
      SIMPLIFY to FALSE. (PR#17653)

as.difftime() gets new optional tz = "UTC" argument which should fix
      behaviour during daylight-savings-changeover days, fixing
      PR#16764, thanks to


      round(x, dig) for _negative_ digits is much more rational now,
      notably for large |dig|.

Inheritance information on S4 classes is maintained more consistently,
      particularly in the case of class unions (in part due to PR#17596
      and a report from Ezra Tucker).

is() behaves more robustly when its argument class2 is a
      classRepresentation object.

The warning message when attempting to export an nonexistent class is
      now more readable; thanks to Thierry Onkelinx for recognizing the
      problem.

choose() misbehaved in corner cases where it switched n - k for k and n
      was only _nearly_ integer (report from Erik Scott Wright).

mle() in the stats4 package had problems combining use of box
      constraints and fixed starting values (in particular, confidence
      intervals were affected).

Operator ? now has lower precedence than = to work as documented, so =
      behaves like <- in help expressions (PR#16710).

smoothEnds(x) now returns integer type in _both_ cases when x is
      integer, thanks to a report and proposal by Bill Dunlap PR#17693.

The methods package does a better job of tracking inheritance
      relationships across packages.

norm(diag(c(1, NA)), "2") now works.

subset() had problems with 0-col dataframes (reported by Bill Dunlap,
      PR#17721).



dotchart() now places the y-axis label (ylab) much better, not
      overplotting labels, thanks to a report and suggestion by Alexey
      Shipunov.

A rare C-level array overflow in chull() has been worked around.

Some invalid specifications of the day-of-the-year (_via_ %j, e.g. day
      366 in 2017) or week plus day-of-the-week are now detected by
      strptime().  They now return NA but give a warning as they may
      have given random results or corrupted memory in earlier versions
      of R.

socketConnection(server = FALSE) now respects the connection timeout
      also on Linux.

socketConnection(server = FALSE) no longer leaks a connection that is
      available right away without waiting (e.g. on localhost).

Socket connections are now robust against spurious readability and
      spurious availability of an incoming connection.

blocking = FALSE is now respected also on the server side of a socket
      connection, allowing non-blocking read operations.



summaryRprof() now should work correctly for the Rprof(*,
      memory.profiling=TRUE) case with small chunk size (and "tseries"
      or similar) thanks to a patch proposal by Benjamin Tyner, in
      PR#15886.

xgettext() ignores strings passed to ngettext(), since the latter is
      handled by xngettext(). Thanks to Daniele Medri for the report
      and all the recent work he has done on the Italian translations.

data(package = "P") for P in base and stats no longer reports the data
      sets from package datasets (which it did for back compatibility
      for 16 years), fixing PR#17730.



Gamma() family sometimes had trouble storing link name PR#15891

  BUG FIXES (Windows):

Sys.glob() now supports all characters from the Unicode Basic
      Multilingual Plane, no longer corrupting some (less commonly
      used) characters (PR#17638).

Rterm now correctly displays multi-byte-coded characters representable
      in the current native encoding (at least on Windows 10 they were
      sometimes omitted, PR#17632).

scan() issues with UTF-8 data when running in a DBCS locale have been
      resolved (PR#16520, PR#16584).

Rterm now accepts enhanced/arrow keys also with ConPTY.

R can can now be started _via_ the launcher icon in a user documents
      directory whose path is not representable in the system encoding.

socketConnection(server = FALSE) now returns instantly also on Windows
      when connection failure is signalled.

Problems with UTF-16 surrogate pairs have been fixed in several
      functions, including tolower() and toupper() (PR#17645).

CHANGES in previous versions:

Older news can be found in text format in files NEWS.0, NEWS.1, NEWS.2
    and NEWS.3 in the doc directory.  News in HTML format for R
    versions 3.x and from 2.10.0 to 2.15.3 is available at
    doc/html/NEWS.3.html and doc/html/NEWS.2.html.

