This file records noteworthy changes. 0.8.1 () * 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 * Added preliminary (re)implementations of color and clifford classes. * simplify_indexed(): contraction of symmetric and antisymmetric tensors is zero. * Some bugfixes (indexed objects, archive writing). 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 and two types of indices: "idx" for simple indices and "varidx" for indices with variance. There are predefined delta, epsilon and metric tensors, and a function simplify_indexed() that performs canonicalization and dummy index summations. Matrix objects can be indexed for doing simple linear algebra. * Added an option "expand_indexed" to expand() to perform expansion of indexed objects like (a+b).i -> a.i + b.i * Renamed get_indices() to get_free_indices(), which no longer returns dummy indices and checks the consistency of indices in sums. * sqrfree() factorization fixed and improved syntactically. * subs() works on matrices. * Matrices can be constructed from flat list of elements; diagonal matrices can be constructed from list of diagonal elements with diag_matrix(). * Fixed memory leak in expand(). * Operator% for objects of class ncmul has gone. Use operator* now for that case too, which is much more natural. 0.7.3 (28 February 2001) * Several bugfixes and minor performance tunings. * Added a section to the tutorial about adding new algebraic classes to GiNaC. * Closed many in-source documentation gaps. 0.7.2 (17 February 2001) * Several bugfixes in power series expansion, one of them critical. 0.7.1 (7 February 2001) * Fix problems with Cint that were caused by CLN's overloaded operator new. * Fix compilation errors with GCC3. * normal() handles large sums of fractions better and normalizes the exponent of power expressions. * expand() always expands the exponent and transforms x^(a+b) -> x^a*x^b. * Some bugfixes of series expansion around branch cuts of special functions. 0.7.0 (15 December 2000) * Requires CLN 1.1 now. Class numeric doesn't use an indirect pointer to the actual representation any more. This is a speedup. * mul::expand() was reengineered to not allocate excess temporary memory. * Non-integer powers of a symbol are treated as constants by (l)degree() and coeff(). Using these functions on an expression containing such powers used to fail with an internal error message. The side-effect is that collect() can be used on expressions which are not polynomials. * Added a man page for the ginac-config script. * Ctor of numeric from char* honors Digits. 0.6.4 (10 August 2000) * Complete revamp of methods in class matrix. Some redundant (and poor) implementations of elimination schemes were thrown out. The code is now highly orthogonal, more flexible and much more efficient. * Some long standing and quite nasty bugs were discovered and fixed in the following functions: add::normal(), heur_gcd(), sr_gcd() and Order_eval(). 0.6.3 (25 July 2000) * Derivatives are now assembled in a slightly different manner (i.e. they might 'look' different on first sight). Under certain circumstances this can result in a dramatic speedup because it gives hashing a better chance, especially when computing higher derivatives. * Some series expansions of built-in functions have been reengineered. * The algorithm for computing determinants can be chosen by the user. See ginac/flags.h and ginac/matrix.h. * The Dilogarithm (Li2) now has floating point evaluation, derivative and a proper series expansion. * Namespace 'std' cleanly disentangled, as demanded by ISO/EIC 14882-1998(E). * Some minor bugfixes, one major lsolve()-bugfix and documentation updates. 0.6.2 (21 June 2000) * ginaccint.bin is now launched by a binary program instead of by a scripts. This allows us to write #!-scripts. A small test suite for GiNaC-cint was added. * Several minor bugfixes. 0.6.1 (18 May 2000) * Cleanup in the interface to Cint. The required version is now Cint 5.14.38. * Several bugfixes in target install. 0.6.0 (11 May 2000) * IMPORTANT: Several interface changes make programs written with GiNaC much clearer but break compatibility with older versions: - f(x).series(x,p[,o]) -> f(x).series(x==p,o) - series(f(x),x,p[,o]) -> series(f(x),x==p,o) - gamma() -> tgamma() (The true Gamma function, there is now also log(tgamma()), called lgamma(), in accord with ISO/IEC 9899:1999.) - EulerGamma -> Euler * #include'ing ginac.h defines the preprocessor symbols GINACLIB_MAJOR_VERSION, GINACLIB_MINOR_VERSION, and GINACLIB_MICRO_VERSION with the respective GiNaC library version numbers. * Expressions can be constructed from strings like this: ex e("2*x+y", lst(x, y)); * ex::to_rational() provides a way to extend the domain of functions like gcd() and divide() that only work on polynomials or rational functions (the good old ex::subs() method reverses this process) * Calling diff() on a function that has no derivative defined returns the inert derivative function "Derivative". * Several new timings in the check target. Some of them may be rather rude at your machine, feel free to interrupt them. 0.5.4 (15 March 2000) * Some algorithms in class matrix (notably determinant) were replaced by less brain-dead ones and should now have much better performance. * Checks were completely reorganized and split up into three parts: a) exams (small regression tests with predefined input) b) checks (lenghty coherence checks with random input) c) timings (for coherence and crude benchmarking) * Behaviour of .evalf() was changed: it doesn't .evalf() any exponents. * Expanded expressions now remember they are expanded to prevent superfluous expansions. * Small bugfixes and improvements in the series expansion. 0.5.3 (23 February 2000) * A more flexible scheme for registering functions was implemented, allowing for remembering, too. * Some Bugfixes. 0.5.2 (16 February 2000) * Mainly fixes a bug in the packaging of release 0.5.1. 0.5.1 (14 February 2000) * Fixes a small number of bugs. 0.5.0 (7 February 2000) * Expressions can be written ("archived") to files and read therefrom. * Addition of GiNaC-cint, which lets you write complete programs in an interactive shell-like manner in your favoured programming language (i.e. C++). 0.4.1 (13 December 1999) * Series Expansion of Gamma function and some other trigonometric functions at their poles works now. * Many more evaluations of special functions at points where exact results exist. * info_flags::rational doesn't return true for complex extensions any more---use info_flags::crational for the old behaviour. info_flags::integer and -::cinteger work similarly, the same holds for types like info_flags::rational_polynomial. 0.4.0 (26 November 1999) * First public release.