1 This file records noteworthy changes.
4 * degree(), ldegree(), coeff(), lcoeff(), tcoeff() and collect() can now
5 be used with constants, functions and indexed expressions as well, so you
6 can use it to collect by powers of Pi or sin(x), or to find the coefficient
9 - it only works with symbols, constants, functions and indexed expressions,
10 trying to find the coefficient of, e.g., "x^2" or "x+y" won't work;
11 - it does not know about dummy index summations; the coefficient of
12 gamma~0 in p.mu*gamma~mu should be p.0 but is returned as 0;
13 - using coeff(), tcoeff(), lcoeff() or collect() on elements of
14 noncommutative products might return wrong or surprising results.
15 * subs() no longer only substitutes symbols and indices but performs a more
16 general "syntactic substitution", i.e. it substitutes whole objects in sub-
17 expressions. You can subs((a+b)^2,a+b==3) and get 9, but subs(a+b+c,a+b==3)
20 - substituting numerics (subs(expr, 2==4)) will not replace then in all
21 occurences; in general, you shouldn't substitute numerics, though.
22 * Added preliminary (re)implementations of color and clifford classes.
23 * simplify_indexed(): contraction of symmetric and antisymmetric tensors
25 * Replaced the various print*() member functions by a single print() that
26 takes a print_context object that determines the output formatting. This
27 should make it easier to add more output types, such as LaTeX output,
28 which is based on work by Stefan Weinzierl.
29 * Added functions to retrieve the properties stored in archive objects
30 outside of unarchive() (for printing or debugging purposes).
31 * Some bugfixes (indexed objects, archive writing).
32 * .collect() on non-polynomials is now algebraically correct.
35 * Complete revamp of indexed objects. Instead of multiple classes for
36 indexed things and their indices there is now only one "indexed" class
37 and two types of indices: "idx" for simple indices and "varidx" for
38 indices with variance. There are predefined delta, epsilon and metric
39 tensors, and a function simplify_indexed() that performs canonicalization
40 and dummy index summations. Matrix objects can be indexed for doing simple
42 * Added an option "expand_indexed" to expand() to perform expansion of
43 indexed objects like (a+b).i -> a.i + b.i
44 * Renamed get_indices() to get_free_indices(), which no longer returns
45 dummy indices and checks the consistency of indices in sums.
46 * sqrfree() factorization fixed and improved syntactically.
47 * subs() works on matrices.
48 * Matrices can be constructed from flat list of elements; diagonal matrices
49 can be constructed from list of diagonal elements with diag_matrix().
50 * Fixed memory leak in expand().
51 * Operator% for objects of class ncmul has gone. Use operator* now for that
52 case too, which is much more natural.
54 0.7.3 (28 February 2001)
55 * Several bugfixes and minor performance tunings.
56 * Added a section to the tutorial about adding new algebraic classes to GiNaC.
57 * Closed many in-source documentation gaps.
59 0.7.2 (17 February 2001)
60 * Several bugfixes in power series expansion, one of them critical.
62 0.7.1 (7 February 2001)
63 * Fix problems with Cint that were caused by CLN's overloaded operator new.
64 * Fix compilation errors with GCC3.
65 * normal() handles large sums of fractions better and normalizes the exponent
67 * expand() always expands the exponent and transforms x^(a+b) -> x^a*x^b.
68 * Some bugfixes of series expansion around branch cuts of special functions.
70 0.7.0 (15 December 2000)
71 * Requires CLN 1.1 now. Class numeric doesn't use an indirect pointer to the
72 actual representation any more. This is a speedup.
73 * mul::expand() was reengineered to not allocate excess temporary memory.
74 * Non-integer powers of a symbol are treated as constants by (l)degree() and
75 coeff(). Using these functions on an expression containing such powers used
76 to fail with an internal error message. The side-effect is that collect()
77 can be used on expressions which are not polynomials.
78 * Added a man page for the ginac-config script.
79 * Ctor of numeric from char* honors Digits.
81 0.6.4 (10 August 2000)
82 * Complete revamp of methods in class matrix. Some redundant (and poor)
83 implementations of elimination schemes were thrown out. The code is now
84 highly orthogonal, more flexible and much more efficient.
85 * Some long standing and quite nasty bugs were discovered and fixed in the
86 following functions: add::normal(), heur_gcd(), sr_gcd() and Order_eval().
89 * Derivatives are now assembled in a slightly different manner (i.e. they
90 might 'look' different on first sight). Under certain circumstances this
91 can result in a dramatic speedup because it gives hashing a better chance,
92 especially when computing higher derivatives.
93 * Some series expansions of built-in functions have been reengineered.
94 * The algorithm for computing determinants can be chosen by the user. See
95 ginac/flags.h and ginac/matrix.h.
96 * The Dilogarithm (Li2) now has floating point evaluation, derivative and a
97 proper series expansion.
98 * Namespace 'std' cleanly disentangled, as demanded by ISO/EIC 14882-1998(E).
99 * Some minor bugfixes, one major lsolve()-bugfix and documentation updates.
102 * ginaccint.bin is now launched by a binary program instead of by a scripts.
103 This allows us to write #!-scripts. A small test suite for GiNaC-cint was
105 * Several minor bugfixes.
108 * Cleanup in the interface to Cint. The required version is now Cint 5.14.38.
109 * Several bugfixes in target install.
112 * IMPORTANT: Several interface changes make programs written with GiNaC
113 much clearer but break compatibility with older versions:
114 - f(x).series(x,p[,o]) -> f(x).series(x==p,o)
115 - series(f(x),x,p[,o]) -> series(f(x),x==p,o)
116 - gamma() -> tgamma() (The true Gamma function, there is now also
117 log(tgamma()), called lgamma(), in accord with ISO/IEC 9899:1999.)
118 - EulerGamma -> Euler
119 * #include'ing ginac.h defines the preprocessor symbols GINACLIB_MAJOR_VERSION,
120 GINACLIB_MINOR_VERSION, and GINACLIB_MICRO_VERSION with the respective GiNaC
121 library version numbers.
122 * Expressions can be constructed from strings like this:
123 ex e("2*x+y", lst(x, y));
124 * ex::to_rational() provides a way to extend the domain of functions like
125 gcd() and divide() that only work on polynomials or rational functions (the
126 good old ex::subs() method reverses this process)
127 * Calling diff() on a function that has no derivative defined returns the
128 inert derivative function "Derivative".
129 * Several new timings in the check target. Some of them may be rather rude
130 at your machine, feel free to interrupt them.
132 0.5.4 (15 March 2000)
133 * Some algorithms in class matrix (notably determinant) were replaced by
134 less brain-dead ones and should now have much better performance.
135 * Checks were completely reorganized and split up into three parts:
136 a) exams (small regression tests with predefined input)
137 b) checks (lenghty coherence checks with random input)
138 c) timings (for coherence and crude benchmarking)
139 * Behaviour of .evalf() was changed: it doesn't .evalf() any exponents.
140 * Expanded expressions now remember they are expanded to prevent
141 superfluous expansions.
142 * Small bugfixes and improvements in the series expansion.
144 0.5.3 (23 February 2000)
145 * A more flexible scheme for registering functions was implemented,
146 allowing for remembering, too.
149 0.5.2 (16 February 2000)
150 * Mainly fixes a bug in the packaging of release 0.5.1.
152 0.5.1 (14 February 2000)
153 * Fixes a small number of bugs.
155 0.5.0 (7 February 2000)
156 * Expressions can be written ("archived") to files and read therefrom.
157 * Addition of GiNaC-cint, which lets you write complete programs in
158 an interactive shell-like manner in your favoured programming
161 0.4.1 (13 December 1999)
162 * Series Expansion of Gamma function and some other trigonometric
163 functions at their poles works now.
164 * Many more evaluations of special functions at points where
166 * info_flags::rational doesn't return true for complex extensions
167 any more---use info_flags::crational for the old behaviour.
168 info_flags::integer and -::cinteger work similarly, the same
169 holds for types like info_flags::rational_polynomial.
171 0.4.0 (26 November 1999)
172 * First public release.