R语言是主要用于统计分析、绘图的语言和操作环境。R本来是由来自新西兰奥克兰大学的Ross Ihaka和Robert Gentleman 开发（也因此称为R），现在由“R开发核心团队”负责。 20170928发布最新版3.4.2 昵称Short Summer （短暂的夏天） 。 NEW FEATURES Setting the LC_ALL category in Sys.setlocale() invalidates any cached locale-specific day/month names and the AM/PM indicator for strptime() (as setting LC_TIME has since R 3.1.0). The version of LAPACK included in the sources has been updated to 3.7.1, a bug-fix release. The default for tools::write_PACKAGES(rds_compress=) has been changed to "xz" to match the compression used by CRAN. c() and unlist() are now more efficient in constructing the names(.) of their return value, thanks to a proposal by Suharto Anggono. (PR#17284) UTILITIES R CMD check checks for and R CMD build corrects CRLF line endings in shell scripts configure and cleanup (even on Windows). INSTALLATION on a UNIX-ALIKE The order of selection of OpenMP flags has been changed: Oracle Developer Studio 12.5 accepts -fopenmp and -xopenmp but only the latter enables OpenMP so it is now tried first. BUG FIXES within(List, rm(x1, x2)) works correctly again, including when List[["x2"]] is NULL. regexec(pattern, text, *) now applies as.character(.) to its first two arguments, as documented. write.table() and related functions, writeLines(), and perhaps other functions writing text to connections did not signal errors when the writes failed, e.g. due to a disk being full. Errors will now be signalled if detected during the write, warnings if detected when the connection is closed. (PR#17243) rt() assumed the ncp parameter was a scalar. (PR#17306) menu(choices) with more than 10 choices which easily fit into one getOption("width")-line no longer erroneously repeats choices. (PR#17312) length()<- on a pairlist succeeds. (https://stat.ethz.ch/pipermail/r-devel/2017-July/074680.html) Language objects such as quote(("\n")) or R functions are correctly printed again, where R 3.4.1 accidentally duplicated the backslashes. Construction of names() for very large objects in c() and unlist() now works, thanks to Suharto Anggono's patch proposals in PR#17292. Resource leaks (and similar) reported by Steve Grubb fixed. (PR#17314, PR#17316, PR#17317, PR#17318, PR#17319, PR#17320) model.matrix(~1, mf) now gets the row names from mf also when they differ from 1:nrow(mf), fixing PR#14992 thanks to the suggestion by Sebastian Meyer. sigma(fm) now takes the correct denominator degrees of freedom for a fitted model with NA coefficients. (PR#17313) hist(x, "FD") no longer “dies” with a somewhat cryptic error message when x has extreme outliers or IQR() zero: nclass.FD(x) tries harder to find a robust bin width h in the latter case, andhist.default(*, breaks) now checks and corrects a too large breaks number. (PR#17274) callNextMethod() works for ... methods. qr.coef(qd, y) now has correct names also when qd is a complex QR or stems from qr(*, LAPACK=TRUE). Setting options(device = *) to an invalid function no longer segfaults when plotting is initiated. (PR#15883) encodeString(<very large string>) no longer segfaults. (PR#15885) It is again possible to use configure --enable-maintainer-mode without having installed notangle (it was required in R 3.4.[01]). S4 method dispatch on ... calls the method by name instead of .Method (for consistency with default dispatch), and only attempts to pass non-missing arguments from the generic. readRDS(textConnection(.)) works again. (PR#17325) (1:n)[-n] no longer segfaults for n <- 2.2e9 (on a platform with enough RAM). x <- 1:2; tapply(x, list(x, x), function(x) "")[1,2] now correctly returns NA. (PR#17333) Running of finalizers after explicit GC request moved from the R interface do_gc to the C interface R_gc. This helps with reclaiming inaccessible connections. help.search(topic) and ??topic matching topics in vignettes with multiple file name extensions (e.g., ‘*.md.rsp’ but not ‘*.Rmd’) failed with an error when using options(help_type = "html"). The X11 device no longer uses the Xlib backing store (PR#16497). array(character(), 1) now gives (a 1D array with) NA as has been documented for a long time as in the other cases of zero-length array initialization and also compatibly with matrix(character(), *). As mentioned there, this also fixes PR#17333. splineDesign(.., derivs = 4) no longer segfaults. fisher.test(*, hybrid=TRUE) now (again) will use the hybrid method when Cochran's conditions are met, fixing PR#16654. R 语言更新到 3.4.2 版本，昵称 Short Summer 下载地址
