* When x is missing and names is not false (including the default
value), Sys.getenv(x, names) returns an object of class "Dlist"
and hence prints tidily.
* (Windows.) shell() no longer consults the environment variable
SHELL: too many systems have been encountered where it was set
incorrectly (usually to a path where software was compiled, not
where it was installed). R_SHELL, the preferred way to select a
non-default shell, can be used instead.
* Some unusual arguments to embedFonts() can now be specified as
character vectors, and the defaults have been changed
* Functions in the Summary group duplicate less. (PR#15798)
* (Unix-alikes.) system(cmd, input = ) now uses
'shell-execution-environment' redirection, which will be more
natural if cmd is not a single command (but requires a
POSIX-compliant shell). (Wish of PR#15508)
* read.fwf() and read.DIF() gain a fileEncoding argument, for
* Graphics devices can add attributes to their description in
.Device and .Devices. Several of those included with R use a
* pmatch() uses hashing in more cases and so is faster at the
expense of using more memory. (PR#15697)
* pairs() gains new arguments to select sets of variables to be
plotted against each other.
* file.info(, extra_cols = FALSE) allows a minimal set of columns
to be computed on Unix-alikes: on some systems without
properly-configured caching this can be significantly faster with
large file lists.
* New function dir.exists() in package base to test efficiently
whether one or more paths exist and are directories.
* dput() and friends gain new controls hexNumeric and digits17
which output double and complex quantities as, respectively,
binary fractions (exactly, see sprintf("%a")) and as decimals
with up to 17 significant digits.
* save(), saveRDS() and serialize() now support ascii = NA which
writes ASCII files using sprintf("%a") for double/complex
quantities. This is read-compatible with ascii = TRUE but avoids
binary->decimal->binary conversions with potential loss of
precision. Unfortunately the Windows C runtime's lack of C99
compliance means that the format cannot be read correctly there
in R before 3.1.2.
* The default for formatC(decimal.mark =) has been changed to be
getOption("OutDec"); this makes it more consistent with format()
and suitable for use in print methods, e.g. those for classes
"density", "ecdf", "stepfun" and "summary.lm".
getOption("OutDec") is now consulted by the print method for
class "kmeans", by cut(), dendrogram(), plot.ts() and quantile()
when constructing labels and for the report from legend(trace =
(In part, wish of PR#15819.)
* printNum() and hence format() and formatC() give a warning if
big.mark and decimal.mark are set to the same value (period and
comma are not uncommonly used for each, and this is a check that
conventions have not got mixed).
* merge() can create a result which uses long vectors on 64-bit
* dget() gains a new argument keep.source which defaults to FALSE
for speed (dput() and dget() are most often used for data objects
where this can make dget() many times faster).
* Packages may now use a file of common macro definitions in their
help files, and may import definitions from other packages.
* A number of macros have been added in the new share/Rd directory
for use in package overview help pages, and promptPackage() now
makes use of them.
* tools::parse_Rd() gains a new permissive argument which converts
unrecognized macros into text. This is used by
utils:::format.bibentry to allow LaTeX markup to be ignored.
* options(OutDec =) can now specify a multi-byte character, e.g.,
options(OutDec = "\u00b7") in a UTF-8 locale.
* is.recursive(x) is no longer true when x is an external pointer,
a weak reference or byte code; the first enables all.equal(x, x)
when x <- getClass(.).
* ls() (aka objects()) and as.list.environment() gain a new
* The "source" attribute (which has not been added to functions by
R since before R version 2.14.0) is no longer treated as special.
* Function returnValue() has been added to give on.exit() code
access to a function's return value for debugging purposes.
* crossprod(x, y) allows more matrix coercions when x or y are
vectors, now equalling t(x) %*% y in these cases (also reported
by Radford Neal). Similarly, tcrossprod(x,y) and %*% work in
more cases with vector arguments.
* Utility function dynGet() useful for detecting cycles, aka
* The byte-code compiler and interpreter include new instructions
that allow many scalar subsetting and assignment and scalar
arithmetic operations to be handled more efficiently. This can
result in significant performance improvements in scalar
* apply(m, 2, identity) is now the same as the matrix m when it has
_named_ row names.
* A new function debuggingState() has been added, allowing to
temporarily turn off debugging.
* example() gets a new optional argument run.donttest and
tools::Rd2ex() a corresponding commentDonttest, with a default
such that example(..) in help examples will run \donttest code
only if used interactively (a change in behaviour).
* rbind.data.frame() gains an optional argument make.row.names, for
* New function extSoftVersion() to report on the versions of
third-party software in use in this session. Currently reports
versions of zlib, bzlib, the liblzma from xz, PCRE, ICU, TRE and
the iconv implementation.
A similar function grSoftVersion() in package grDevices reports
on third-party graphics software.
Function tcltk::tclVersion() reports the Tcl/Tk version.
* Calling callGeneric() without arguments now works with primitive
generics to some extent.
* vapply(x, FUN, FUN.VALUE) is more efficient notably for large
length(FUN.VALUE); as extension of PR#16061.
* as.table() now allows tables with one or more dimensions of
length 0 (such as as.table(integer())).
* names(x) <- NULL now clears the names of call and ... objects.
* library() will report a warning when an insufficient dependency
version is masking a sufficient one later on the library search
* A new plot() method for class "raster" has been added.
* New check_packages_in_dir_changes() function in package tools for
conveniently analyzing how changing sources impacts the check
results of their reverse dependencies.
* Speed-up from Peter Haverty for ls() and
methods:::.requirePackage() speeding up package loading.
* New get0() function, combining exists() and get() in one call,
* match.call() gains an envir argument for specifying the
environment from which to retrieve the ... in the call, if any;
this environment was wrong (or at least undesirable) when the
definition argument was a function.
* topenv() has been made .Internal() for speedup, based on Peter
Haverty's proposal in PR#16140.
* getOption() no longer calls options() in the main case.
* Optional use of libcurl (version 7.28.0 from Oct 2012 or later)
for Internet access:
* capabilities("libcurl") reports if this is available.
* libcurlVersion() reports the version in use, and other
details of the "libcurl" build including which URL schemes it
* curlGetHeaders() retrieves the headers for http://, https://,
ftp:// and ftps:// URLs: analysis of these headers can
provide insights into the `existence' of a URL (it might for
example be permanently redirected) and is so used in R CMD
* download.file() has a new optional method "libcurl" which
will handle more URL schemes, follow redirections, and allows
simultaneous downloads of multiple URLs.
* url() has a new method "libcurl" which handles more URL
schemes and follows redirections. The default method is
controlled by a new option url.method, which applies also to
the opening of URLs _via_ file() (which happens implicitly in
functions such as read.table.)
* When file() or url() is invoked with a https:// or ftps://
URL which the current method cannot handle, it switches to a
suitable method if one is available.
* (Windows.) The DLLs internet.dll and internet2.dll have been
merged. In this version it is safe to switch (repeatedly)
between the internal and Windows internet functions within an R
The Windows internet functions are still selected by flag
--internet2 or setInternet2(). This can be overridden for an
url() connection _via_ its new method argument.
download.file() has new method "wininet", selected as the default
by --internet2 or setInternet2().
* parent.env<- can no longer modify the parent of a locked
namespace or namespace imports environment. Contributed by Karl
* New function isLoadedNamespace() for readability and speed.
* names(env) now returns all the object names of an environment
env, equivalently to ls(env, all.names = TRUE, sorted = FALSE)
and also to the names of the corresponding list,
names(as.list(env, all.names = TRUE)). Note that although
names() returns a character vector, the names have no particular
* The memory manager now grows the heap more aggressively. This
reduces the number of garbage collections, in particular while
data or code are loaded, at the expense of slightly increasing
the memory footprint.
* New function trimws() for removing leading/trailing whitespace.
* cbind() and rbind() now consider S4 inheritance during S3
dispatch and also obey deparse.level.
* cbind() and rbind() will delegate recursively to methods::cbind2
(methods::rbind2) when at least one argument is an S4 object and
S3 dispatch fails (due to ambiguity).
* (Windows.) download.file(quiet = FALSE) now uses text rather
than Windows progress bars in non-interactive use.
* New function hsearch_db() in package utils for building and
retrieving the help search database used by help.search(), along
with functions for inspecting the concepts and keywords in the
help search database.
* New function .getNamespaceInfo(), a no-check version of
getNamespaceInfo() mostly for internal speedups.
* The help search system now takes \keyword entries in Rd files
which are not standard keywords (as given in KEYWORDS in the R
documentation directory) as concepts. For standard keyword
entries the corresponding descriptions are additionally taken as
* New lengths() function for getting the lengths of all elements in
* New function toTitleCase() in package tools, tailored to package
* The matrix methods of cbind() and rbind() allow matrices as
inputs which have 2^31 or more elements. (For cbind(), wish of
* The default method of image() has an explicit check for a numeric
or logical matrix (which was always required).
* URLencode() will not by default encode further URLs which appear
to be already encoded.
* BIC(mod) and BIC(mod, mod2) now give non-NA numbers for arima()
fitted models, as nobs(mod) now gives the number of "used"
observations for such models. This fixes PR#16198, quite
differently than proposed there.
* The print() methods for "htest", "pairwise.htest" and
"power.htest" objects now have a digits argument defaulting to (a
function of) getOption("digits"), and influencing all printed
numbers coherently. Unavoidably, this changes the display of
such test results in some cases.
* Code completion for namespaces now recognizes all loaded
namespaces, rather than only the ones that are also attached.
* The code completion mechanism can now be replaced by a
user-specified completer function, for (temporary) situations
where the usual code completion is inappropriate.
* unzip() will now warn if it is able to detect truncation when
unpacking a file of 4GB or more (related to PR#16243).
* methods() reports S4 in addition to S3 methods; output is
simplified when the class argument is used. .S3methods() and
methods::.S4methods() report S3 and S4 methods separately.
* Higher order functions such as the apply functions and Reduce()
now force arguments to the functions they apply in order to
eliminate undesirable interactions between lazy evaluation and
variable capture in closures. This resolves PR#16093.
INSTALLATION and INCLUDED SOFTWARE:
* The \donttest sections of R's help files can be tested by
make check TEST_DONTTEST=TRUE .
* It is possible to request the use of system valgrind headers
_via_ configure option --with-system-valgrind-headers: note the
possible future incompatibility of such headers discussed in the
'R Installation and Administration' manual. (Wish of PR#16068.)
* The included version of liblzma has been updated to xz-utils
5.0.7 (minor bug fixes from 5.0.5).
* configure options --with-system-zlib, --with-system-bzlib and
--with-system-pcre are now the default. For the time being there
is fallback to the versions included in the R sources if no
system versions are found or (unlikely) if they are too old.
Linux users should check that the -devel or -dev versions of
packages zlib, bzip2/libbz2 and pcre as well as
xz-devel/liblzma-dev (or similar names) are installed.
* configure by default looks for the texi2any script from texinfo
5.1 or later, rather than the makeinfo program. (makeinfo is a
link to the Perl script texi2any in texinfo 5.x.)
* R CMD INSTALL gains an option --built-timestamp=STAMP allowing
100% reproducible package building, thanks to Dirk Eddelbuettel.
* There is support for testing the \dontrun and \donttest parts of
examples in packages.
tools::testInstalledPackage() accepts new arguments
commentDontrun = FALSE and commentDonttest = FALSE.
R CMD check gains options --run-dontrun and --run-donttest.
* The HTML generated by tools::Rd2HTML() and tools::toHTML()
methods is now 'XHTML 1.0 Strict'.
* The compiler package's utility function setCompilerOptions() now
returns the old values invisibly. The initial optimization level
can also be set with the environment variable
* R CMD build adds a NeedsCompilation field if one is not already
present in the DESCRIPTION file.
* R CMD check gains option --test-dir to specify an alternative set
of tests to run.
* R CMD check will now by default continue with testing after many
types of errors, and will output a summary count of errors at the
end if any have occurred.
* R CMD check now checks that the Title and Description fields are
* R CMD check --as-cran now:
* checks a README.md file can be processed: this needs pandoc
* checks the existence and accessibility of URLs in the
DESCRIPTION, CITATION, NEWS.Rd and README.md files and in the
help files (provided the build has libcurl support).
* reports non-ASCII characters in R source files when there is
no package encoding declared in the DESCRIPTION file.
* reports (apparent) S3 methods exported but not registered.
* reports overwriting registered S3 methods from
base/recommended packages. (Such methods are replaced in the
affected package for the rest of the session, even if the
replacing namespace is unloaded.)
* reports if the Title field does not appear to be in title
case (see 'Writing R Extensions': there may be false
positives, but note that technical words should be
single-quoted and will then be accepted).
Most of these checks can also be selected by environment
variables: see the 'R Internals' manual.
* New C API utility logspace_sum(logx, n).
* Entry points rbinom_mu, rnbinom_mu and rmultinom are remapped (by
default) to Rf_rbinom_mu etc. This requires packages using them
to be re-installed.
* .C(DUP = FALSE) and .Fortran(DUP = FALSE) are now ignored, so
arguments are duplicated if DUP = TRUE would do so. As their
help has long said, .Call() is much preferred.
* New entry point R_allocLD, like R_alloc but guaranteed to have
sufficient alignment for long double pointers.
* isPairList() now returns TRUE for DOTSXP.
WINDOWS BUILD CHANGES:
A number of changes to the Windows build system are in development.
The following are currently in place.
* Installation using external binary distributions of zlib, bzip2,
liblzma, pcre, libpng, jpeglib and libtiff is now required, and
the build instructions have been revised.
* A new make target rsync-extsoft has been added to obtain copies
of the external libraries from CRAN.
* Building the manuals now requires texi2any from texinfo 5.1 or
later. CRAN binary builds include the manuals, but by default
builds from source will not, and they will be accessed from CRAN.
See the comments in src/gnuwin32/MkRules.dist for how to specify
the location of texi2any.
* (Windows) Changes have been made to support an experimental
Windows toolchain based on GCC 4.9.2. The default toolchain
continues to be based on GCC 4.6.3, as the new toolchain is not
yet stable enough. A change to a new toolchain is expected
during the R 3.2.x lifetime.
* (Windows) The use of macro ZLIB_LIBS in file src/Makevars.win
(which has not been documented for a long time) now requires an
external libz.a to be available (it is part of the 'goodies' used
to compile Windows binary packages). It would be simpler to use
* The default for option pkgType on platforms using binary packages
is now "both", so source packages will be tried if binary
versions are not available or not up to date.
There are options for what install.packages(type = "both")
(possibly called _via_ update.packages()) will do if compilation
of a source package is desirable: see ?options (under utils).
If you intend not to accept updates as source packages, you
should use update.packages(type = "binary").
DEPRECATED AND DEFUNCT:
* download.file(method = "lynx") is defunct.
* Building R using the included versions of zlib, bzip2, xz and
PCRE is deprecated: these are frozen (bar essential bug-fixes)
and will be removed for R 3.3.0.
* The configure option --with-valgrind-instrumentation=3 has been
withdrawn, as it did not work with recent valgrind headers: it is
now treated as level 2.
* The MethodsList class in package methods had been deprecated in R
2.11.0 and is defunct now. Functions using it are defunct if
they had been deprecated in R 2.11.0, and are deprecated now,
* Fixed two obscure bugs in pairlist subassignment, reported by
Radford Neal as part of pqR issue 16.
* Fixes for bugs in handling empty arguments and argument matching
by name in log().
* all.equal() gains methods for environments and refClasses.
* [<- and [[<- gain S4 data.frame methods to avoid corruption of S4
class information by the S3 methods.
* callNextMethod() should now work within a .local call when ... is
absent from formals(.local).
* dput(pairlist(x)) generates a call to the pairlist constructor
instead of the list constructor.
* Fix missing() when arguments are propagated through ... .
* eigen(m) now defaults to symmetric = TRUE even when the dimnames
are asymmetric if the matrix is otherwise symmetric. (PR#16151)
* Fix issues with forwarding ... through callGeneric() and
* callGeneric() now works after a callNextMethod().
* Subclass information is kept consistent when replacing an
ordinary S4 class with an "old class" _via_ the S4Class argument
to setOldClass(). Thus, for example, a data.frame is valid for a
list argument in the signature, and a factor is valid for vector
* In qbeta() the inversion of pbeta() is much more sophisticated.
This works better in corner cases some of which failed completely
previously (PR#15755), or were using too many iterations.
* Auto-printing no longer duplicates objects when printing is
dispatched to a method.
* kmeans(x, k) would fail when nrow(x) >= 42949673. (Comment 6 of
* 'Abbreviated' locale-specific day and month names could have been
truncated in those rare locales where there are the same as the
* An irrelevant warning message from updating subclass information
was silenced (the namespace would not be writable in this case).