X-Git-Url: https://www.ginac.de/ginac.git//ginac.git?p=ginac.git;a=blobdiff_plain;f=NEWS;h=af84e795c70f2dd6ca4cd823b1db387a908d346c;hp=8fbd57cdab99ad0c6a542c464b74a4658bc13453;hb=12b715014f888fd191a15b87a8d1b597019f1904;hpb=c359f10c53b7338b6f883f661697cb630cc5ab4a diff --git a/NEWS b/NEWS index 8fbd57cd..af84e795 100644 --- a/NEWS +++ b/NEWS @@ -1,5 +1,48 @@ This file records noteworthy changes. +0.9.0 () +* In the output and in ginsh, lists are now delimited by { } braces, and + matrices are delimited by single [ ] brackets. +* simplify_indexed() renames dummy indices so, e.g., "a.i*a.i+a.j*a.j" gets + simplified to "2*a.i*a.i" (or "2*a.j*a.j"). +* New functions/methods: + - canonicalize_clifford() (helpful when comparing expressions containing + Dirac matrices) + - symmetrize() and antisymmetrize() + - numer_denom() (return numerator and denominator in one call) + - map() (apply function to subexpressions) + - evalm() (evaluate sums, products and integer powers of matrices) +* Added a new function match() for performing pattern matching. subs() and + has() also accept patterns as arguments. A pattern can be any expression, + optionally containing wildcard objects. These are constructed with the + call "wild()" and are denoted as "$0", "$1" etc. in the output + and in ginsh. +* Positive integer powers of non-commutative expressions (except matrices) + are automatically expanded. +* Removed cint subdirectory, ginaccint is a separate package now due to + packaging considerations. +* Several little bugfixes. + +0.8.3 (11 May 2001) +* color and clifford classes are functional and documented. +* New "spinidx" class for dotted/undotted indices. +* Predefined spinor metric tensor (created by spinor_metric()). +* Symbols can have a LaTeX name, e.g. symbol s("s", "\\sigma"); +* LaTeX output of indexed objects is much nicer. +* Fixed some build problems (with recent libreadline). +* Semantics of arithmetic operators now follows the C++ rules more strictly. + +0.8.2 (24 April 2001) +* degree(), ldegree(), coeff(), lcoeff(), tcoeff() and collect() work with + non-symbols as the second argument in ginsh. +* the argument to collect() can be a list of objects in which case the + result is either a recursively collected polynomial, or a polynomial in + a distributed form with terms like coeff*x1^e1*...*xn^en, as specified by + the second argument to collect(). +* Several bugfixes (including a nasty memory leak in .normal()). +* class matrix: solve() doesn't call algorithms redundantly any more and + inverse() falls back to solve() which works in more general cases. + 0.8.1 (16 April 2001) * degree(), ldegree(), coeff(), lcoeff(), tcoeff() and collect() can now be used with constants, functions and indexed expressions as well, so you