X-Git-Url: https://ginac.de/ginac.git/static/gitweb.css/ginac.git?a=blobdiff_plain;f=NEWS;h=14306999cc55bcbf4bf728bf2052e2ea1c5197d3;hb=6d7e9e718bc7236dc29e0ca51a53d6c213296e66;hp=934d6caa9392c747be30feb95379f8a3bd2ac448;hpb=197594750cb42582eb69c8690fea2221e3f72205;p=ginac.git diff --git a/NEWS b/NEWS index 934d6caa..14306999 100644 --- a/NEWS +++ b/NEWS @@ -1,5 +1,52 @@ This file records noteworthy changes. +0.8.3 () +* 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). + +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 + can use it to collect by powers of Pi or sin(x), or to find the coefficient + of gamma~0. + Limitations: + - it only works with symbols, constants, functions and indexed expressions, + trying to find the coefficient of, e.g., "x^2" or "x+y" won't work; + - it does not know about dummy index summations; the coefficient of + gamma~0 in p.mu*gamma~mu should be p.0 but is returned as 0; + - using coeff(), tcoeff(), lcoeff() or collect() on elements of + noncommutative products might return wrong or surprising results. +* subs() no longer only substitutes symbols and indices but performs a more + general "syntactic substitution", i.e. it substitutes whole objects in sub- + expressions. You can subs((a+b)^2,a+b==3) and get 9, but subs(a+b+c,a+b==3) + doesn't do anything. + Limitations: + - substituting numerics (subs(expr, 2==4)) will not replace then in all + occurences; in general, you shouldn't substitute numerics, though. +* Added preliminary (re)implementations of color and clifford classes. +* simplify_indexed(): contraction of symmetric and antisymmetric tensors + is zero. +* Replaced the various print*() member functions by a single print() that + takes a print_context object that determines the output formatting. This + should make it easier to add more output types, such as LaTeX output, + which is based on work by Stefan Weinzierl. +* Added functions to retrieve the properties stored in archive objects + outside of unarchive() (for printing or debugging purposes). +* Some bugfixes (indexed objects, archive writing). +* .collect() on non-polynomials is now algebraically correct. + 0.8.0 (24 March 2001) * Complete revamp of indexed objects. Instead of multiple classes for indexed things and their indices there is now only one "indexed" class