Date: Wed, 23 Apr 1997 21:25:23 +1200 (NZST) From: Ross Ihaka <ihaka@stat.auckland.ac.nz> Message-Id: <199704230925.VAA24453@stat1.stat.auckland.ac.nz> To: r-announce@stat.math.ethz.ch Subject: R-beta: Version 0.49 Released The newest version of R for Unix (version 0.49) is now available (or soon will be) from the following sites. NORTH AMERICA: http://lib.stat.cmu.edu/R/Alpha EUROPE: ftp://ftp.stat.math.ethz.ch/R/ ftp://statlab.uni-heidelberg.de/pub/mirrors/auckland/R/ JAPAN: ftp://ftp.u-aizu.ac.jp/pub/lang/R/ NEW ZEALAND: ftp://stat.auckland.ac.nz/pub/R/ Please obtain a copy from site close to you. Note that New Zealand is not close to anywhere other than itself :-). This version adds considerable functionality and (we hope) stability to R. Most notably, the object system is now very close to that of S and we now have a fairly full implementation of complex arithmetic. The jump in version number (from 0.16) relects the fact that we feel that this version of R represents quite a jump toward what we hope will be in our eventual 1.0 release. However the version is numbered 0.49 rather than the 0.50 we touted because it falls a little short of what we really want for 0.50. Immediate development of R will focus on creating a coherent way of loading and unloading "libraries" and creating a good framework for documentation (can you say "SGML" - I knew you could). A (partial) list of changes from 0.16.1 follows. A list of known problems is kept in the file "TASKS" in the distribution and a list of problems we think are solved is in "TASKS.OLD" R + R ------------------------------------------------------------------- CHANGES IN VERSION R VERSION 0.49 ALPHA NEW FEATURES o The ``object'' system has been changed substantially. The behavior of both "UseMethod" and "NextMethod" should match that in S. Group methods for "Math", "Ops" and "Summary" are available. o Complex arithmetic is now implemented. Many mathematical functions are now defined for complex arguments (e.g. sqrt, exp, log, sin, cos, tan, asin, acos, atan). There is no complex gamma function or log gamma function yet. The summary functions "mean", "sum", "prod", "cumsum" and "cumprod" work correctly when (some of) their arguments are complex. Other functions such as "solve" are not "complex aware" yet, but do print warning messages about coercion of complex values to real by the dropping of imaginary parts. S and R do not return identical results in all cases: S> atan(tan(1i)) [1] 0-1i R> atan(tan(1i)) [1] 0+1i [ Is this just a difference on the branch cut boundary? ] o The full set of S graphics symbols is now available with pch=0:18. In addition, there is a special set of R plotting symbols which can be obtained with pch=29:25. pch=19 solid circle pch=20 bullet pch=21 circle pch=22 square pch=23 diamond pch=24 triangle point-up pch=25 triangle point down The symbols 21:25 can be colored and filled with different colors. For example, the expression points(x, y, pch=21, col="red", bg="yellow") will plot the points using a symbol consisting of a red circle with a yellow interior. o There is a new "family" argument to the postscript graphics driver which can be set to any of "AvantGarde", "Bookman", "Courier", "Helvetica", "Helvetica-Narrow", "NewCenturySchoolbook", "Palatino" or "Times". In addition, setting font=5 will cause the "Symbol" family to be used. This is still experimental and it is hard to see it being useful without some sort of math capability. [ Such a facility is "on the drawing board". ] o The graphics parameter "las" is now implemented and can be used to rotate axis labels. E.g. plot(1:10, las=1) . o The hyperbolic and inverse hyperbolic functions cosh, sinh, tanh, acosh, asinh and atanh are now implemented for both real and complex arguments. (Q: are the underlying functions available on all platforms, or do we need compatibility fixes?) o "log" has changed so that it will accept an optional "base" argument. "log2" and "log10" are implemented this way. o "atan" can now either be invoked as atan(x) or atan(x,y). o The behavior of "fft" has been modified to match that of S (i.e. it returns a complex value. There is also a function "mvfft" which performs a "vector transform" when passed a matrix (i.e. it applies the fft to each column, rather than doing a 2d spatial transform). o A new functon "polyroot" can be used to find the roots of polynomials with (real or) complex coefficients. o Vectors and lists are now "stretchy". This means that the following is legal x <- 1:10 x[20] <- 12 [ Note that there is a bug in S. When you try this kind of extension - the "dim" and "dimname" attributes are not dropped, leading to "invisible" elements in the result. ] o Symbolic differention is now available using the functions "D" and "deriv". The results are slightly difference in appearance from those of S (which tends to put in a few too many parentheses), but should provide identical semantics. To see the nature of the difference, try the expression D(expression(tan(x)/x^2),"x") in both systems. These functions are implemented as internal code in R (what's the point in having a nice little underlying lisp if you don't use it for obvious list processing applications?). o A new function "grep" has been implemented. It performs regular expression matching based on POSIX 1003.3. The function uses the "regex" library written by Henry Spencer (the same one that Perl uses). Grep is now used to provide a pattern matching facility in "objects" and "ls". In addition, there are functions "sub" and "gsub" which operate the same way as those in "nawk". Note that "\" must be escaped to get it into a string, so if you want a literal "\" you must type "\\\\" :-(. o A new "methods" function written by Martin Maechler replaces the older less sophisticated one. This has also been converted to use the new "grep" function. o A new version of model.frame from Thomas Lumley is included. o Factors and ordered factors are now "objects" with class attributes which match those in S. This change is primarily so that applications written for S will work in R. The underlying implementation for factors and ordered factors still uses special underlying types. o R will now do conditioning plots as described in the S "Models" book. Some thought is going into "doing trellis". o Thomas Lumley's "require" and "provide" functions for library organization added. o There is a new graphical parameter "gamma" which is designed to let users apply a ``gamma'' correction for their graphics displays. Most monitors produce a color intensity which is related to voltage by the equation intensity = voltage ^ gamma with gamma about 2.5 for most PC monitors. A typical symptom of this non-linearity is that a colorwheel produced by piechart(rep(1,48), col=48) shows a marked over representation of the red, green and blue and blue primaries. If this is the case try par(gamma=1/2.5) and redraw the color wheel. Vary gamma till you have a "nice" spectrum. This is experimental and feedback would be welcome. (If this is useful we will do the same for postscript). BUG FIXES & ENHANCEMENTS o The internals of the postscript device drivers have been rewritten in preparation for "doing equations". The Adobe font metrics are no longer processed during the build process. The original files are now processed directly by the driver. The postscript emitted by the drivers should conform to the Adobe 3.0 standard. o Typos and logic errors in "crossprod" pointed out by Arne Kovac have been fixed. o "round" now works using IEEE rounding on platforms which support it. E.g. > round(.5 + -3:7) [1] -2 -2 0 0 2 2 4 4 6 6 8 o A change to the PostScript graphics device driver change should stop plots from rotating unexpectedly when viewed with ghostview and other postscript viewers. o Patches from Kurt Hornik for "structure" and "help" have been applied. o "names" applied to 1-d arrays now does the "right thing" i.e. it returns the first component of the "dimnames" attribute rather than NULL. Subsetting a 1-d array as a vector will produce a "names" attribute on the result. o "atan" will now accept either 1 or 2 arguments ("atan2" still exists). o "nchar" and "format" preserve "dim" and "dimname" attributes where possible. o There were problems with arguments in "switch". These have been fixed. There appears to be a bug in S with the expression z <- switch(1, a=, b=10, 20) mode(z) They appear to return a "missing argument". We die with an error message. What is the right thing to do here? o Problems deparsing arguments of the form "a"= and a=, have been fixed. o The default graphics line width is now 1 rather than 0. o "as.is" problem in "read.table" pointed out by Peter Dalgaard fixed. o paste(list(character(0),""), 1:2) no longer causes a segfault. "as.character" applied to a list now returns the vector obtained by deparsing each element of the list. o "attach" now attaches objects at pos=2 when directed. o Memory usage was measured in 1000 byte chunks with the -v flag. This has been changed to 1024 byte chunks. o Dependency on the "OSF sprintf bug" has been removed. =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-= r-help mailing list -- Read http://www.ci.tuwien.ac.at/~hornik/R/R-FAQ.html Send "info", "help", or "[un]subscribe" (in the "body", not the subject !) To: r-help-request@stat.math.ethz.ch =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=