- GiNaC-devel - ginac.de

problem with powers.
by Chris Dams 16 Dec '03

16 Dec '03

Hello, Expanding an expression by calling the .expand() method is obsoleted by the now preferred method of the so-called "repeated reciprocal". You want to expand a*(a+b)? Here is how this is done nowadays. ex test = a*(a+b) ex expanded_test = 1/(1/test) Then again, maybe this was not the idea. A patch that is supposed to remove this feature from GiNaC is attached. Have a nice day, Chris

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want to know about gamma function
by SOMKIAT TRAKULTRAIPRUK 02 Dec '03

02 Dec '03

How to prove that gamma(3x) = 1/2pi * 3^(2x-1/2) * gamma(x) * gamma(x+1/3) * gamma(x+2/3) Thanks. --------------------------------- Do you Yahoo!? Free Pop-Up Blocker - Get it now

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patch for expand.
by Chris Dams 02 Dec '03

02 Dec '03

Hello everybody, I found out that calling the expand() method on an expression like (d*sqrt(a+b)+a*sqrt(c+d))*(b*sqrt(a+b)+a*sqrt(c+d)) results in sqrt(b+a)*b*sqrt(d+c)*a+(d+c)*a^2+d*(b+a)*b+d*sqrt(b+a)*sqrt(d+c)*a This result could be further expanded. A patch that is supposed to make this happen is attached. Best regards, Chris

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Re: ACM Sigsam: Computer Algebra System Bibliography
by Richard B. Kreckel 24 Nov '03

24 Nov '03

Hi Alexander! On Mon, 24 Nov 2003, Alexander Hulpke wrote: > Dear Author(s) of the computer algebra system GiNaC. > > (if you are not (any longer) affiliated with this CAS, but know the current > authors/maintainers, it would be very helpful if you could forward this mail > to them, or if you could send me a short 'not here' reply.) CC'd to <ginac-devel(a)ginac.de>. > As you may know, SIGSAM, the ACM special interest group for symbolic > computation, has started to build a collection of bibliographic references > for computer algebra systems (CAS). > > The aim of such a collection is to persuade publishers, as well as authors, > to cite use of a CAS in the same formal way as use of a paper, thus giving > credit to the CAS developer(s). > (See http://www.acm.org/sigsam/citation/policy.html for more details.) > > Alas the current version of this bibliography is missing many important > CAS or is outdated. > > The aim of this mail is to solicit your input for such a citation for GiNaC. > This citation could be a reference to a journal article describing the > CAS, the CAS manual, or just the CAS itself. In our case, I would suggest to simply cite the (non-)CAS itself. There is a journal article, easily to be found on our web-page. However, I hardly think that a printed description of a snapshot in time can capture any ongoing work in a fair way. I'm afraid most people would not hesitate and give a journal reference. But in the case of evolving software that reference will be outdated ere the paper appears in print. And it would only be in support of the publishing industry. I'm afraid that citing web pages isn't much good either, since "the average lifespan of a Web page today is 100 days. This is no way to run a culture", as the board chairman of the Internet Archive says. (This is certainly exaggerated in our case; but it is appropiate and appeard on slashdot only an hour ago.) Alas, if you think about it, the whole idea about citations is in support of the publishing industry as long as printed papers prevail and free alternatives are still in their infancy (no, non-peer-reviewed arXiv does not count). In this spirit and in the presence of indexes into the internet and packaged versions of the software shipped with some OSes, I would much rather prefer to simply have the package stand for itself. Just imagine, go ask B!ll Gat3z for a reference of M$-Word... ;-) If some other developer thinks that this is too much Nirvana-talk, please go ahead and provide Alexander Hulpke with more conservative input. We should respect this and not object. After all, journal references are still quite relevant for a scientific career. > Some issues you might want to consider for this are: > > - Is the authorship of this citation representative of all the CAS authors? > > - One big advantage of a uniform citation is the possibility to use data > bases such as the science citation index to search for publications citing > your CAS. (Such lists can be useful for example in tenure or promotion > cases.) > For such a search, however the citation has to be reasonably stable. (You > might want to keep author lists and large parts of the title to be stable > between versions to ease such a search.) > > - Some citation bases prefer citations that give a place and year of > publication. > > May I ask you to fill out/correct the appended form (simply as a text file) > and to send the result back to me (hulpke(a)math.colostate.edu) > > If you are happy to be the 'public face' for the CAS ands there is no > separate email for the CAS, simply copy the entry at 4 to the entry at 3 (we > will not publish your address unless you explicitly listed the address there). > > For the citation BiBTeX is easiest to handle for producing the bibliography > in the end, but if you only have a Text version this is fine as well. > If you know MR or ZBl numbers for a review you can add entries for them > as well. > > You can use the final text field to add a sentence or two that describes > what your CAS does (someone stumbling upon the list might otherwise > wonder what all the systems actually are). > > If you have several CAS (or versions of the CAS) that you would like > to be listed separately, please return one copy of the form for each such > CAS. > > Thank you very much for your help and cooperation! > > Alexander Hulpke > > -- Colorado State University, Department of Mathematics, > Weber Building, 1874 Campus Delivery, Fort Collins, CO 80523-1874, USA > email: hulpke(a)math.colostate.edu, Phone: ++1-970-4914288 > http://www.math.colostate.edu/~hulpke > > ----------------------------------------------------------------------------- > > 1. System Name: > GiNaC > > 2. URL (Web page address) for the system: <http://www.ginac.de/> > 3. Public contact: I suggest the mailing lists: <ginac-devel(a)ginac.de> and <ginac-list(a)ginac.de> > 4. Contact (only for updating this list. Will default to 3) [ My Address deleted ] I suggest to let it default to 3. > 5. Citation: As explained, I'ld suggest to leave it at: "GiNaC is Not a CAS". > 6. Descriptive text (at most 5 lines) that will be added to the citation list I base this suggestion from the RPM package description: : GiNaC (which stands for "GiNaC is Not a CAS (Computer Algebra System)") : is an open framework for symbolic computation within the C++ programming : language. Published under the GPL. Best wishes und nix für ungut! -richy. -- Richard B. Kreckel <Richard.Kreckel(a)GiNaC.DE> <http://www.ginac.de/~kreckel/>

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GiNaC 1.1.5 now available
by Christian Bauer 05 Nov '03

05 Nov '03

Hello! "Release Early, Release Often" The GiNaC Group is pleased to announce the immediate availability of GiNaC 1.1.5 which contains lots of improvements to the nestedsums functions: - Harmonic polylogarithms now numerically evaluate for arbitrary arguments (parameter must still be positive integers). - The zeta function now can also be given a lst as a parameter in which case it becomes a multiple zeta value. The use of mZeta is deprecated. - The order of parameters for the multiple polylogarithm has been corrected. - Documentation for the nested sums functions zeta, harmonic polylog, multiple polylog, etc. has been added. Run, don't walk, to everyone's favorite FTP server: ftp://ftpthep.physik.uni-mainz.de/pub/GiNaC/ Have a nice day, Christian -- / Physics is an algorithm \/ http://www.uni-mainz.de/~bauec002/

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Broken link in www.ginac.de
by Roy at SEVENtwentyfour Inc. 30 Oct '03

30 Oct '03

There appears to be a problem on this page of your site. On page http://www.ginac.de/tutorial/tutorial_8.html when you click on "C++-FAQ lite", the link to http://www.cerfnet.com/~mpcline/c++-faq-lite/ gives the error: Domain name lookup failed (may be a transient error). As recommended by the Robot Guidelines, this email is to explain our robots activities and to let you know about one of the broken links we encountered. LinkWalker does not store or publish the content of your pages, but rather uses the link information to update our map of the World Wide Web. Are these reports helpful? I'd love some feedback. If you prefer not to receive these occasional error notices please let me know. Roy Bryant ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Roy Bryant, roybryant(a)seventwentyfour.com President SEVENtwentyfour Inc. ("Always watching the Web") http://www.seventwentyfour.com ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

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Problem report
by John Fletcher 26 Oct '03

26 Oct '03

Hello I attach a program which compiles and runs and asks to be reported. A copy of that message is as a comment in the code. System: Red Hat 9.0 with gcc 3.2 cln 1.1.5 and GiNaC 1.1.4 installed with no extra options (recently installed). A word about what I am trying to do. I want to use the ex class as a template parameter something<ex> and the class something< > makes use of Boost and deep inside wants to convert GiNaC::ex to double and cannot find a way to do this. I want to provide a default way to satisfy that request EVEN IF IT DOES NOT MAKE SENSE to get under way the use of GiNaC for symbolic calculation inside the template class. This is very much a "first action". The later action includes a more thorough use of GiNaC to replace the Boost library within the template class. I have already done something similar with a different symbolic algebra in C++. Thanks John Fletcher ------------------------------------------------------------------- Dr John P. Fletcher Tel: (44) 121 359 3611 ext 4625 Chemical Engineering and Applied Chemistry (CEAC), School of Engineering and Applied Science (SEAS), Aston University, Fax: (44) 121 359 4094 Aston Triangle, Email: J.P.Fletcher(a)aston.ac.uk BIRMINGHAM B4 7ET U.K. CEAC Web site http://www.ceac.aston.ac.uk/ The following section of this message contains a file attachment prepared for transmission using the Internet MIME message format. If you are using Pegasus Mail, or any other MIME-compliant system, you should be able to save it or view it from within your mailer. If you cannot, please ask your system administrator for assistance. ---- File information ----------- File: test.cpp Date: 23 Oct 2003, 23:56 Size: 539 bytes. Type: Program-source

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Announcing GiNaC 1.1.4
by Richard B. Kreckel 17 Oct '03

17 Oct '03

* It has defied the world's greatest mathematicians. * It lies in wait wherever problems gather. * It is a timeless force with the power to change the course of history. Dear software aficionado, It is our pleasure to introduce GiNaC release 1.1.4. For the true software collecting enthusiast, this is a release like no other -- explaining, illuminating, and illustrating in depth how the bits, bytes and exabytes of the computing machinery more often than not solve problems of undreamed complexity. GiNaC 1.1.4 -- an opus like no other available today -- will bring you to the crossroads of mathematics and computing. Quite simply, GiNaC-1.1.4 is an unparalleled resource no serious software connoisseur can afford to overlook. Take advantage of this singular opportunity and download your very own copy today from URL <ftp://ftpthep.physik.uni-mainz.de/pub/GiNaC>. Best regards -rbk. -- Richard B. Kreckel <Richard.Kreckel(a)GiNaC.DE> <http://www.ginac.de/~kreckel/>

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how to construct a ex in GiNaC
by cbq 17 Oct '03

17 Oct '03

I read the GiNaC code ,found a question. Under GiNaC namespace ,the under code works well. //***this is my code: ............ #include "ginac/ginac.h" using namespace GiNaC; ............ int main(void) { symbol a("a"),b("b"); ex ex0(a+b); cout<<"ex0 = "<<ex0<<endl; return 0; } // end the code but i find nothing about method ex(symbol) in GiNaC. how does the above statement ex ex0(a) work? help me !! thanks! best regards, Boqun Cheng 2003.10.17

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installation problem and/or internal error of GiNaC 1.1.3
by anaximander＠gmx.de 29 Sep '03

29 Sep '03

Hallo (in Mainz spricht man noch Deutsch, oder?) anbei schicke ich ein C++ Programm, das bei der Ausfuehrung (bei mir) auf zwei interne Fehler in GiNaC 1.1.3 verweist. Allerdings war, trotz neuester Versionen sämtlicher Bibliotheken, schon die Kompilierung von GiNaC 1.1.3 nicht ganz erfolgreich Ein Test misslang: examining series expansion.........../run_exams: line 3: 12967 segment fault Ich hab's zu Probezwecken dennoch installiert. Alle technischen Details, Compilerversionen etc stehen in der C++ Datei. Mit vielen Gruessen, und Dank fuer euer tolles System!! Volkmar Klatt PS: Habe auf einem anderen Rechner auch die Intel Compiler Version 7.1 installiert, nur falls Testpersonen gesucht werden... -- NEU FÜR ALLE - GMX MediaCenter - für Fotos, Musik, Dateien... Fotoalbum, File Sharing, MMS, Multimedia-Gruß, GMX FotoService Jetzt kostenlos anmelden unter http://www.gmx.net +++ GMX - die erste Adresse für Mail, Message, More! +++

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