This blog is updated daily.
A general description is here.
New function untar() to list or unpack tar archives, possibly compressed. This uses either an external 'tar' command or an internal implementation.
New functions memCompress() and memDecopmress() for in-memory compression and decompression.
bzfile() has a 'compress' argument to select the amount of effort put into compression when writing.
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-comppressed files (where supported).
There is the new option of save(compress = "bzip2") to use bzip2 compression (which will be slower, but can give substantially smaller files). load() can read such saves (but only as from this version of R). Also "xz" where supported.
R CMD INSTALL/check and tools::writePACKAGES accept a wider range of compressed tar archives. Precisely how wide depends on the capabilities of the host system's 'tar' command: they almost always include .tar.bz2 archives, and with modern versions of 'tar' other forms of compression such as lzma and xz, and arbitrary extensions.
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.
New function untar() to list or unpack tar archives, possibly
compressed. This uses either an external 'tar' command or an
internal implementation.
R CMD INSTALL/check and tools::writePACKAGES accept a wider
range of compressed tar archives. Precisely how wide depends
on the capabilities of the host system's 'tar' command: they
almost always include .tar.bz2 archives, and with modern
versions of 'tar' other forms of compression such as lzma and
xz, and arbitrary extensions.
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'.
gzfile() looks at the file header and so can now also read
bzip2-ed files and xv-comppressed files (where supported).
There is the new option of save(compress = "bzip2") to use bzip2
compression (which will be slower, but can give substantially
smaller files). load() can read such saves (but only as from
this version of R).
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.
Where there is suitable OS support --data-compress=xz can be
used, often giving substantially better compression on large
datasets at the expense of much slower installation times.
New function memCompress() memDecopmress() for in-memory
compression and decompression.
In registering an S3 class by a call to setOldClass(), the data part (e.g., the object type) required for the class can be included as one of the superclasses in the Classes argument.
The argument f= to showMethods() can be an expression evaluating to a generic function, allowing methods to be shown for non-exported generics and other nonstandard cases.