X-Git-Url: https://www.ginac.de/ginac.git//ginac.git?p=ginac.git;a=blobdiff_plain;f=NEWS;h=d5d29512a9ccdf74aaebe4d2f1eca3860781982a;hp=14306999cc55bcbf4bf728bf2052e2ea1c5197d3;hb=c8e2c9967b23aac88c91771dac5d1f5f04589f18;hpb=fdade42bf337fa1650bb9d69ee06e3bd1562c951 diff --git a/NEWS b/NEWS index 14306999..d5d29512 100644 --- a/NEWS +++ b/NEWS @@ -1,9 +1,35 @@ This file records noteworthy changes. -0.8.3 () +0.8.4 () +* 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". +* New functions/methods: + - canonicalize_clifford() (helpful when comparing expressions containing + Dirac matrices) + - symmetrize() and antisymmetrize() + - numer_denom() (return numerator and denominator) + - map() (apply function to subexpressions) + - evalm() (evaluate sums and products 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. +* Fixed possible crash when calling subs() on expressions with non-commutative + products. +* Positive integer powers of non-commutative expressions are automatically + expanded. + +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. -* Fix some build-problems (with recent libreadline). +* 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