This blog is updated daily..
A general description is here.
Package help is now converted from Rd by the R-based converters that were first introduced in 2.9.0. This means
- Packages that were installed by R-devel after 2009-08-09 should not be used with earlier versions of R, and some aspects of package help will be missing if therey are so used. (Text, HTML and latex help and the runnable examples.)
- Text, HTML and latex help and examples for packages installed under the new system are converted on-demand from stored parsed Rd files. (Conversions stored in R < 2.10.0 are used if no parsed Rd files are found.)
- Rd version 2 is required in help files.
Name subscripts in data.frame methods for [ and [[ now gives a
warning. (Names are ignored in the default method, but could
have odd semantics for other methods, and do for the
data.frame ones.)
Naming subscripts (e.g. x[i=1, j=2]) in data.frame methods for [ and [[ now gives a warning. (Names are ignored in the default method, but could have odd semantics for other methods, and do for the data.frame ones.)
New print() (S3) method for class "function", also used for auto-printing. Further, .Primitive functions now print and auto-print identically. The new method is based on code suggestions by Romain Franççois.
for(), while(), and repeat() loops now always return NULL as their (invisible) value. This change was needed to address a reference counting bug without creating performance penalties for some common use cases.
factor(NULL) now returns the same as factor(''[0])character(0)) instead of an error, and table(NULL) consequently does analogously.
New function xzfile() for use with xz-compressed files, if suitable OS support is found at configuration. (This can also read files compressed by some versions of 'lzma'.) The new capabilities("xz") reports if it is supported.
gzfile() looks at the file header and so can now also read bzip2-ed files and xv-compressed files (where supported).
There isare the new options of save(compress = "bzip2") and "xz" to use bzip2 or xz compression (which will be slower, but can give substantially smaller files).smaller files). Argument compression_level gives finer control over the space/time tradeoffs.
load() can read such saves (but only as from this version of R). Also "xz" where supported.
R CMD INSTALL has a new option --data-compress to control the compression used when lazy-loading data. One new option is --data-compress=bzip2 which will give ca 15% better compression at the expense of slower installation times. Also --data-compress=xz where supported, often giving even better compression on large datasets at the expense of much slower installation times.
Assigning into a raw vector with an index vector containing NA could cause a segfault. Reported by Hervé Pagès.
Rscript would segfault if its filename argument was not provided. Reported by Martin Morgan.
gregexpr() no longer segfaults when "" is given as the search pattern. Thanks to Hervéé Pagèès for the bug report.
CHAR() now returns (const char *) since CHARSXPs should no longer be modified in place. This change allows compilers to warn or error about improper modification. Thanks to Hervéé Pagèès for the suggestion.