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Release 0.9.0 just hit the web
by Richard B. Kreckel 07 Jun '01

07 Jun '01

Go, grab your copy now, as long as supply lasts! Don't let others snatch away the few copies left at <ftp://ftpthep.physik.uni-mainz.de/pub/GiNaC/>! Hurry!!! Pronto!! ¡Rapido! Los! The NEWS file says: * 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(<unsigned>)" 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. * More exclamation marks than ever in the announcement. - To UNSUBSCRIBE, email to ginac-list(a)ginac.de with a subject of "unsubscribe".

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Expand does not expands?
by zellerin＠winbase.software602.cz 28 May '01

28 May '01

Hello, I got to GiNaC only recently, and I have some troubles with the expand() function. I would expect following code -------- #include <ginac/ginac.h> using namespace GiNaC; symbol x("x"), y("y"); ex laplace_in_oblates(const ex& potential) { ex x_part=diff((x*x-1)*diff(potential,x), x); ex y_part=diff((1-y*y)*diff(potential,y), y); return normal(x_part+y_part); } int main() { ex R=sqrt(x*x+y*y-1); ex tmp=expand(pow(R, 5)*laplace_in_oblates(1/R)); cout << tmp<<" = "<<tmp.normal() << endl; return 0; } --------- to yield 0 = 0, but it gives 3*(-1+x^2+y^2)*y^2-3*x^2+3*x^4-3*(-1+x^2+y^2)*x^2-3*y^4+3*y^2 = 0 I would say that the polynomial on the left side is not expanded, in spite of the fact that it should be result of an expand. Anyone give me a hint what I am doing/expecting wrong? (tried on GiNaC version 0.6.4 on RedHat Linux 6.1 and GiNaC 0.8.3 on RH 7.1) Thanks Tomas Zellerin - To UNSUBSCRIBE, email to ginac-list(a)ginac.de with a subject of "unsubscribe".

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GiNaC build error (non-local fct uses anonymous type)
by george moudry 15 May '01

15 May '01

Hello GiNaC! I downloaded GiNaC-0.8.3.tar.bz2, but I'm having trouble building it on my system. My computer has SuSE 7.1 with gcc version 2.96 20000731. Here's the build error: make[2]: Entering directory `/home/gg/down2/math/GiNaC-0.8.3/ginac' /bin/sh ../libtool --mode=compile c++ -DHAVE_CONFIG_H -I. -I. -I.. -I/usr/local/include -g -O2 -c inifcns.cpp rm -f .libs/inifcns.lo c++ -DHAVE_CONFIG_H -I. -I. -I.. -I/usr/local/include -g -O2 -c inifcns.cpp -fPIC -DPIC -o .libs/inifcns.lo In file included from inifcns.cpp:31: matrix.h:125: non-local function `GiNaC::ex GiNaC::determinant (const GiNaC::matrix &, unsigned int = GiNaC::determinant_algo::automatic)' uses anonymous type make[2]: *** [inifcns.lo] Error 1 make[2]: Leaving directory `/home/gg/down2/math/GiNaC-0.8.3/ginac' make[1]: *** [all-recursive] Error 1 make[1]: Leaving directory `/home/gg/down2/math/GiNaC-0.8.3' make: *** [all-recursive-am] Error 2 Thanks for any help, /george moudry los angeles PS. I saw on the ginac.de website that some people were installing an RPM. Would you know where to download it from? PPS. The GiNaC screenshot is incredible! I really did think it crashed my browser. - To UNSUBSCRIBE, email to ginac-list(a)ginac.de with a subject of "unsubscribe".

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Version 0.8.3 is on the wire.
by Richard B. Kreckel 11 May '01

11 May '01

This is from the NEWS file: - 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). (*) - Semantics of arithmetic operators now follows the C++ rules more strictly. (*) Hi Julian! ;-) Enjoy -richy. -- Richard Kreckel <Richard.Kreckel(a)Uni-Mainz.DE> <http://wwwthep.physik.uni-mainz.de/~kreckel/> - To UNSUBSCRIBE, email to ginac-list(a)ginac.de with a subject of "unsubscribe".

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gTybalt 0.0.4
by Stefan Weinzierl 03 May '01

03 May '01

Dear all, for those who are interested, I put a new version of gTybalt on the web. (http://www.fis.unipr.it/~stefanw/gtybalt.html) gTybalt is a small program build on top of some other packages (GiNaC, TeXmacs, Root, ...) and provides basically TeX-type fonts output for GiNaC and some basic plotting routines. The installation of the new version has become a little bit more user-friendlier, no modifications or adjustment of TeXmacs or GiNaC are needed any more. Enjoy it, Stefan - To UNSUBSCRIBE, email to ginac-list(a)ginac.de with a subject of "unsubscribe".

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Version 0.8.2...
by Richard B. Kreckel 24 Apr '01

24 Apr '01

...claims to feature the following new stuff: * 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. Enjoy -richy. -- Richard Kreckel <Richard.Kreckel(a)Uni-Mainz.DE> <http://wwwthep.physik.uni-mainz.de/~kreckel/> - To UNSUBSCRIBE, email to ginac-list(a)ginac.de with a subject of "unsubscribe".

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The easter release 0.8.1 has finally landed.
by Richard B. Kreckel 16 Apr '01

16 Apr '01

Hello all, Now let's quickly start finding all those easter eggs that Christian has promised to stuff into the code! This is what's documented in the NEWS file: * 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. Happy hacking -richy. -- Richard Kreckel <Richard.Kreckel(a)Uni-Mainz.DE> <http://wwwthep.physik.uni-mainz.de/~kreckel/> - To UNSUBSCRIBE, email to ginac-list(a)ginac.de with a subject of "unsubscribe".

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collect() eats fractions
by Pearu Peterson 12 Apr '01

12 Apr '01

Hi! In ginsh (ginac V0.8.0): > x/(1+x); (1+x)^(-1)*x > collect(x/(1+x),x); 0 <----??? > collect(1+x/(1+x),x); 1 <----??? > collect(x+x/(1+x),x); (1+(1+x)^(-1))*x Is this GiNaC bug or feature? Pearu - To UNSUBSCRIBE, email to ginac-list(a)ginac.de with a subject of "unsubscribe".

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Is ncmul depreciated?
by Pearu Peterson 09 Apr '01

09 Apr '01

Hi! I have noticed that ncmul(2,a,3) results mul(a,6). Why is this type change ncmul -> mul? Will ncmul be depreciated in future? Pearu - To UNSUBSCRIBE, email to ginac-list(a)ginac.de with a subject of "unsubscribe".

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failed asertion
by Ben Sapp 29 Mar '01

29 Mar '01

I am trying to use GiNaC in, GNU Octave, an interactive scripting language used primarily for numerical analysis. Below, I provide some output from octave. Can you provide any clues as to what I may be doing to make the following assertion to fail? What can I do to fix it? octave:1> symbols installing ex type at type-id = 18 installing sym type at type-id = 19 installing vpa type at type-id = 20 octave:2> page_screen_output = 0; octave:3> x = sym("x") x = x octave:4> x^2 octave: basic.h:77: GiNaC::basic::~basic(): Assertion `(!(flags & status_flags::dynallocated))||(refcount==0)' failed. -- Ben Sapp Los Alamos National Laboratory email: <mailto:bsapp@lanl.gov> Phone: (505)667-3277 Fax: (505)665-7920 URL: http://www.neutrino.lanl.gov/ -- - To UNSUBSCRIBE, email to ginac-list(a)ginac.de with a subject of "unsubscribe".

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