- GiNaC-list - ginac.de

symbolic expressions: machine precision calculation
by Dr. Vassilis S. Vassiliadis 10 Jul '03

10 Jul '03

I wonder if there is a possibility to use within GiNaC the C++ native precision arithmetic rather than that of CLN. In particular, following symbolic generation and manipulation of a mathematical model, it would be desirable in many cases to switch to machine arithmetic for numerical computations based on the tree of each constructed expression of interest. Such a possibility would obviate the need to spool external C++ source code, to recompile externally from the application built on GiNaC in the first place, and would lead to usability of GiNaC in limitless domains where eventual efficient numerical computation is paramount. Mathematica, although in a rudimentary and rather cumbersome way, has this option for example (the so-called compiled version of a function). Vassilis. ----------------------------------------------------------------- Dr. Vassilis S. Vassiliadis, Lecturer, UNIVERSITY OF CAMBRIDGE, DEPARTMENT OF CHEMICAL ENGINEERING Pembroke Street, Cambridge CB2 3RA, UK. Tel: (reception): +44 1223 334777 Fax: (departmental): +44 1223 334796 e-mail: vsv20(a)cheng.cam.ac.uk -----------------------------------------------------------------

1 0

nestedsums for GiNaC 1.1
by Christian Bauer 03 Jul '03

03 Jul '03

Hi! Due to the popularity of Stefan Weinzierl's nestedsums library (see http://www.fis.unipr.it/~stefanw/nestedsums/) I have taken the liberty to create a version of the library that works with GiNaC 1.1. Sources and pre-packaged RPM files can be found in ftp://ftpthep.physik.uni-mainz.de/pub/nestedsums/ Changes to the original nestedsums 1.1.1 include: - adapted to GiNaC 1.1 API - testsuite can be run with "make check" - includes a nestedsums.m4 that provides an AM_PATH_NESTEDSUMS macro for autoconf scripts - includes a spec file for RPM generation Happy nesting, Christian -- / Physics is an algorithm \/ http://www.uni-mainz.de/~bauec002/

1 0

Multivariate polynomial factorization
by poulard 02 Jul '03

02 Jul '03

Dear all, I have a great challenge to manage and a deep thinking before beginning the developpement. First before entering into the real subject I wish tell you (if it has not been before) that GiNaC+CLN compile well on W2K under cygwin with gcc (gcc version 3.2 20020927 (prerelease)) All chech and tests are ok! Great job. NOW THE REAL SUBJECT OF THE MAIL -------------------------------- For one of our project WE DEFINITLY need a package for multivariate polynomial factorization under Z. For this I will have rapidely the man.power to begin this great challenge (next week). My great wish would be to work within open-source framework. As this subject is one of the ToDo list of GiNac, and a very difficult task. Before compiling GiNaC, I beleived that I could use it as a native library un Win32. But it seems that not, unless modification. Perhaps someone has did it ? I have a constraint that I can't modify : I MUST BE ABLE to use and link with a classic native win32 application. So, unless someone tell me the modification to do to be able to compile cln + ginac under VC6++ I cannot use ginac as a basis for further developpment. ----------------------------------------------------------- The solution for me today is the use of NTL (which compile well with VC6) as univariate basis. ----------------------------------------------------------- BUT the developpement of this package under NTL could serve as a basis for GiNac also ! So I need you help for this developpement at a information level. --------------------------------------------------------- What is today the best method for multivariate polynomial factorization under Z ? --------------------------------------------------------- I have the old algorithm from Berlekamp & Hensel for univariate (p-adique method) and only an extension for multivariate, but the algorithm complexity seems to be very high, and I guess that new algorithms have been found far now ? Someone could help me to indicate what is today the best algorithm for this task ? REMARK = The rapidity and accuracy of the result of such task made by Maple5 indicates that there should be a quit rapid algorithm ! For finish this - call to contribution - , I must be honest and indicate that the polynom I have to factorize are little special : - they are very very very long in term of monomial : the number of monomial could be 100, 1000 !!! - they could be a lot of variable (when I say a lot, it could be 10 and more) !!!! - THEY ARE homogeneous : the total degree of monomial are always the same - The coefficient of each monomial is : 1, 2 or not very high - IT SEEMS, after lot experiment under Maple5 that they are squarre free (BUT we have not demonstrate this assertion) UNDER this condition I can tell you that the kernel of Maple5 (in Matlab), for a HUGE HUGE polynomial like I describe, result is almost immediate !!!!! Very very speed. I hope that it will interest you to collaborate and help me to develop this piece of software under open-source. Herve PS = If you the modification to do to GiNaC to be able to be a native win32 library is not to complex I promiss to collaborate to do this task. Thank you, if you have read all :-) _/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/ _/ Dr Herve Poulard | ACTIA - ACTIELEC Hold. _/ _/ Research Manager | BP 4215 _/ _/ Tel : (33) 5.61.17.68.79 | 25 Chemin de Pouvourville _/ _/ Fax : (33) 5.61.55.42.31 | 31432 Toulouse Cedex 04 _/ _/ | FRANCE _/ _/ E-Mail | _/ _/ - poulard(a)actia.fr | http://www.actia.com/ _/ _/ - poulard(a)laas.fr | http://www.laas.fr/~poulard/ _/ _/ - poulard.herve(a)wanadoo.fr | http://www.actielec.com/ _/ _/ (plz cc for security) | _/ _/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/

2 1

Strange behavior of numer_denom
by Roberto Bagnara 30 Jun '03

30 Jun '03

Hi there, in the following session, numer_denom is computed several times on the same expression (using the up-arrow history recall mechanism): $ ./ginsh ginsh - GiNaC Interactive Shell (GiNaC V1.1.1) __, _______ Copyright (C) 1999-2003 Johannes Gutenberg University Mainz, (__) * | Germany. This is free software with ABSOLUTELY NO WARRANTY. ._) i N a C | You are welcome to redistribute it under certain conditions. <-------------' For details type `warranty;'. Type ?? for a list of help topics. > numer_denom((-(4/79*I)*(-1/8+(1/8*I)*sqrt(79))*sqrt(79)-(4/79*I)*(1/8+(1/8*I)*sqrt(79))*sqrt(79))*d-(3/79*I)*(1/8-(1/8*I)*sqrt(79))^2*sqrt(79)+(3/79*I)*(1/8+(1/8*I)*sqrt(79))^2*sqrt(79)-(4/79*I)*(-3/32-(3/32*I)*sqrt(79))*sqrt(79)-(4/79*I)*(3/32-(3/32*I)*sqrt(79))*sqrt(79)+(-(4/79*I)*(-1/32-(1/32*I)*sqrt(79))*sqrt(79)-(4/79*I)*(1/32-(1/32*I)*sqrt(79))*sqrt(79)+(4/79*I)*(1/8-(1/8*I)*sqrt(79))^2*sqrt(79)-(4/79*I)*(1/8+(1/8*I)*sqrt(79))^2*sqrt(79))*c-3/4*(-(1/8-(1/8*I)*sqrt(79))^2-(1/4*I)*sqrt(79)+(1/8-(1/8*I)*sqrt(79))*(1/8+(1/8*I)*sqrt(79)))^(-1)*(1/8-(1/8*I)*sqrt(79))^3+3/4*(-(1/8-(1/8*I)*sqrt(79))^2-(1/4*I)*sqrt(79)+(1/8-(1/8*I)*sqrt(79))*(1/8+(1/8*I)*sqrt(79)))^(-1)*(1/8-(1/8*I)*sqrt(79))-3/4*((1/8+(1/8*I)*sqrt(79))^2-(1/4*I)*sqrt(79)+(-1/8+(1/8*I)*sqrt(79))*(1/8+(1/8*I)*sqrt(79)))^(-1)*(1/8+(1/8*I)*sqrt(79))+3/4*((1/8+(1/8*I)*sqrt(79))^2-(1/4*I)*sqrt(79)+(-1/8+(1/8*I)*sqrt(79))*(1/8+(1/8*I)*sqrt(79)))^(-1)*(1/8+(1/8*I)*sqrt(79))^3); {-1264*d,-1264} > numer_denom((-(4/79*I)*(-1/8+(1/8*I)*sqrt(79))*sqrt(79)-(4/79*I)*(1/8+(1/8*I)*sqrt(79))*sqrt(79))*d-(3/79*I)*(1/8-(1/8*I)*sqrt(79))^2*sqrt(79)+(3/79*I)*(1/8+(1/8*I)*sqrt(79))^2*sqrt(79)-(4/79*I)*(-3/32-(3/32*I)*sqrt(79))*sqrt(79)-(4/79*I)*(3/32-(3/32*I)*sqrt(79))*sqrt(79)+(-(4/79*I)*(-1/32-(1/32*I)*sqrt(79))*sqrt(79)-(4/79*I)*(1/32-(1/32*I)*sqrt(79))*sqrt(79)+(4/79*I)*(1/8-(1/8*I)*sqrt(79))^2*sqrt(79)-(4/79*I)*(1/8+(1/8*I)*sqrt(79))^2*sqrt(79))*c-3/4*(-(1/8-(1/8*I)*sqrt(79))^2-(1/4*I)*sqrt(79)+(1/8-(1/8*I)*sqrt(79))*(1/8+(1/8*I)*sqrt(79)))^(-1)*(1/8-(1/8*I)*sqrt(79))^3+3/4*(-(1/8-(1/8*I)*sqrt(79))^2-(1/4*I)*sqrt(79)+(1/8-(1/8*I)*sqrt(79))*(1/8+(1/8*I)*sqrt(79)))^(-1)*(1/8-(1/8*I)*sqrt(79))-3/4*((1/8+(1/8*I)*sqrt(79))^2-(1/4*I)*sqrt(79)+(-1/8+(1/8*I)*sqrt(79))*(1/8+(1/8*I)*sqrt(79)))^(-1)*(1/8+(1/8*I)*sqrt(79))+3/4*((1/8+(1/8*I)*sqrt(79))^2-(1/4*I)*sqrt(79)+(-1/8+(1/8*I)*sqrt(79))*(1/8+(1/8*I)*sqrt(79)))^(-1)*(1/8+(1/8*I)*sqrt(79))^3); {-1264*d,-1264} > numer_denom((-(4/79*I)*(-1/8+(1/8*I)*sqrt(79))*sqrt(79)-(4/79*I)*(1/8+(1/8*I)*sqrt(79))*sqrt(79))*d-(3/79*I)*(1/8-(1/8*I)*sqrt(79))^2*sqrt(79)+(3/79*I)*(1/8+(1/8*I)*sqrt(79))^2*sqrt(79)-(4/79*I)*(-3/32-(3/32*I)*sqrt(79))*sqrt(79)-(4/79*I)*(3/32-(3/32*I)*sqrt(79))*sqrt(79)+(-(4/79*I)*(-1/32-(1/32*I)*sqrt(79))*sqrt(79)-(4/79*I)*(1/32-(1/32*I)*sqrt(79))*sqrt(79)+(4/79*I)*(1/8-(1/8*I)*sqrt(79))^2*sqrt(79)-(4/79*I)*(1/8+(1/8*I)*sqrt(79))^2*sqrt(79))*c-3/4*(-(1/8-(1/8*I)*sqrt(79))^2-(1/4*I)*sqrt(79)+(1/8-(1/8*I)*sqrt(79))*(1/8+(1/8*I)*sqrt(79)))^(-1)*(1/8-(1/8*I)*sqrt(79))^3+3/4*(-(1/8-(1/8*I)*sqrt(79))^2-(1/4*I)*sqrt(79)+(1/8-(1/8*I)*sqrt(79))*(1/8+(1/8*I)*sqrt(79)))^(-1)*(1/8-(1/8*I)*sqrt(79))-3/4*((1/8+(1/8*I)*sqrt(79))^2-(1/4*I)*sqrt(79)+(-1/8+(1/8*I)*sqrt(79))*(1/8+(1/8*I)*sqrt(79)))^(-1)*(1/8+(1/8*I)*sqrt(79))+3/4*((1/8+(1/8*I)*sqrt(79))^2-(1/4*I)*sqrt(79)+(-1/8+(1/8*I)*sqrt(79))*(1/8+(1/8*I)*sqrt(79)))^(-1)*(1/8+(1/8*I)*sqrt(79))^3); {1264*d,1264} > numer_denom((-(4/79*I)*(-1/8+(1/8*I)*sqrt(79))*sqrt(79)-(4/79*I)*(1/8+(1/8*I)*sqrt(79))*sqrt(79))*d-(3/79*I)*(1/8-(1/8*I)*sqrt(79))^2*sqrt(79)+(3/79*I)*(1/8+(1/8*I)*sqrt(79))^2*sqrt(79)-(4/79*I)*(-3/32-(3/32*I)*sqrt(79))*sqrt(79)-(4/79*I)*(3/32-(3/32*I)*sqrt(79))*sqrt(79)+(-(4/79*I)*(-1/32-(1/32*I)*sqrt(79))*sqrt(79)-(4/79*I)*(1/32-(1/32*I)*sqrt(79))*sqrt(79)+(4/79*I)*(1/8-(1/8*I)*sqrt(79))^2*sqrt(79)-(4/79*I)*(1/8+(1/8*I)*sqrt(79))^2*sqrt(79))*c-3/4*(-(1/8-(1/8*I)*sqrt(79))^2-(1/4*I)*sqrt(79)+(1/8-(1/8*I)*sqrt(79))*(1/8+(1/8*I)*sqrt(79)))^(-1)*(1/8-(1/8*I)*sqrt(79))^3+3/4*(-(1/8-(1/8*I)*sqrt(79))^2-(1/4*I)*sqrt(79)+(1/8-(1/8*I)*sqrt(79))*(1/8+(1/8*I)*sqrt(79)))^(-1)*(1/8-(1/8*I)*sqrt(79))-3/4*((1/8+(1/8*I)*sqrt(79))^2-(1/4*I)*sqrt(79)+(-1/8+(1/8*I)*sqrt(79))*(1/8+(1/8*I)*sqrt(79)))^(-1)*(1/8+(1/8*I)*sqrt(79))+3/4*((1/8+(1/8*I)*sqrt(79))^2-(1/4*I)*sqrt(79)+(-1/8+(1/8*I)*sqrt(79))*(1/8+(1/8*I)*sqrt(79)))^(-1)*(1/8+(1/8*I)*sqrt(79))^3); {-1264*d,-1264} > numer_denom((-(4/79*I)*(-1/8+(1/8*I)*sqrt(79))*sqrt(79)-(4/79*I)*(1/8+(1/8*I)*sqrt(79))*sqrt(79))*d-(3/79*I)*(1/8-(1/8*I)*sqrt(79))^2*sqrt(79)+(3/79*I)*(1/8+(1/8*I)*sqrt(79))^2*sqrt(79)-(4/79*I)*(-3/32-(3/32*I)*sqrt(79))*sqrt(79)-(4/79*I)*(3/32-(3/32*I)*sqrt(79))*sqrt(79)+(-(4/79*I)*(-1/32-(1/32*I)*sqrt(79))*sqrt(79)-(4/79*I)*(1/32-(1/32*I)*sqrt(79))*sqrt(79)+(4/79*I)*(1/8-(1/8*I)*sqrt(79))^2*sqrt(79)-(4/79*I)*(1/8+(1/8*I)*sqrt(79))^2*sqrt(79))*c-3/4*(-(1/8-(1/8*I)*sqrt(79))^2-(1/4*I)*sqrt(79)+(1/8-(1/8*I)*sqrt(79))*(1/8+(1/8*I)*sqrt(79)))^(-1)*(1/8-(1/8*I)*sqrt(79))^3+3/4*(-(1/8-(1/8*I)*sqrt(79))^2-(1/4*I)*sqrt(79)+(1/8-(1/8*I)*sqrt(79))*(1/8+(1/8*I)*sqrt(79)))^(-1)*(1/8-(1/8*I)*sqrt(79))-3/4*((1/8+(1/8*I)*sqrt(79))^2-(1/4*I)*sqrt(79)+(-1/8+(1/8*I)*sqrt(79))*(1/8+(1/8*I)*sqrt(79)))^(-1)*(1/8+(1/8*I)*sqrt(79))+3/4*((1/8+(1/8*I)*sqrt(79))^2-(1/4*I)*sqrt(79)+(-1/8+(1/8*I)*sqrt(79))*(1/8+(1/8*I)*sqrt(79)))^(-1)*(1/8+(1/8*I)*sqrt(79))^3); {-1264*d,-1264} > numer_denom((-(4/79*I)*(-1/8+(1/8*I)*sqrt(79))*sqrt(79)-(4/79*I)*(1/8+(1/8*I)*sqrt(79))*sqrt(79))*d-(3/79*I)*(1/8-(1/8*I)*sqrt(79))^2*sqrt(79)+(3/79*I)*(1/8+(1/8*I)*sqrt(79))^2*sqrt(79)-(4/79*I)*(-3/32-(3/32*I)*sqrt(79))*sqrt(79)-(4/79*I)*(3/32-(3/32*I)*sqrt(79))*sqrt(79)+(-(4/79*I)*(-1/32-(1/32*I)*sqrt(79))*sqrt(79)-(4/79*I)*(1/32-(1/32*I)*sqrt(79))*sqrt(79)+(4/79*I)*(1/8-(1/8*I)*sqrt(79))^2*sqrt(79)-(4/79*I)*(1/8+(1/8*I)*sqrt(79))^2*sqrt(79))*c-3/4*(-(1/8-(1/8*I)*sqrt(79))^2-(1/4*I)*sqrt(79)+(1/8-(1/8*I)*sqrt(79))*(1/8+(1/8*I)*sqrt(79)))^(-1)*(1/8-(1/8*I)*sqrt(79))^3+3/4*(-(1/8-(1/8*I)*sqrt(79))^2-(1/4*I)*sqrt(79)+(1/8-(1/8*I)*sqrt(79))*(1/8+(1/8*I)*sqrt(79)))^(-1)*(1/8-(1/8*I)*sqrt(79))-3/4*((1/8+(1/8*I)*sqrt(79))^2-(1/4*I)*sqrt(79)+(-1/8+(1/8*I)*sqrt(79))*(1/8+(1/8*I)*sqrt(79)))^(-1)*(1/8+(1/8*I)*sqrt(79))+3/4*((1/8+(1/8*I)*sqrt(79))^2-(1/4*I)*sqrt(79)+(-1/8+(1/8*I)*sqrt(79))*(1/8+(1/8*I)*sqrt(79)))^(-1)*(1/8+(1/8*I)*sqrt(79))^3); {1264*d,1264} > numer_denom((-(4/79*I)*(-1/8+(1/8*I)*sqrt(79))*sqrt(79)-(4/79*I)*(1/8+(1/8*I)*sqrt(79))*sqrt(79))*d-(3/79*I)*(1/8-(1/8*I)*sqrt(79))^2*sqrt(79)+(3/79*I)*(1/8+(1/8*I)*sqrt(79))^2*sqrt(79)-(4/79*I)*(-3/32-(3/32*I)*sqrt(79))*sqrt(79)-(4/79*I)*(3/32-(3/32*I)*sqrt(79))*sqrt(79)+(-(4/79*I)*(-1/32-(1/32*I)*sqrt(79))*sqrt(79)-(4/79*I)*(1/32-(1/32*I)*sqrt(79))*sqrt(79)+(4/79*I)*(1/8-(1/8*I)*sqrt(79))^2*sqrt(79)-(4/79*I)*(1/8+(1/8*I)*sqrt(79))^2*sqrt(79))*c-3/4*(-(1/8-(1/8*I)*sqrt(79))^2-(1/4*I)*sqrt(79)+(1/8-(1/8*I)*sqrt(79))*(1/8+(1/8*I)*sqrt(79)))^(-1)*(1/8-(1/8*I)*sqrt(79))^3+3/4*(-(1/8-(1/8*I)*sqrt(79))^2-(1/4*I)*sqrt(79)+(1/8-(1/8*I)*sqrt(79))*(1/8+(1/8*I)*sqrt(79)))^(-1)*(1/8-(1/8*I)*sqrt(79))-3/4*((1/8+(1/8*I)*sqrt(79))^2-(1/4*I)*sqrt(79)+(-1/8+(1/8*I)*sqrt(79))*(1/8+(1/8*I)*sqrt(79)))^(-1)*(1/8+(1/8*I)*sqrt(79))+3/4*((1/8+(1/8*I)*sqrt(79))^2-(1/4*I)*sqrt(79)+(-1/8+(1/8*I)*sqrt(79))*(1/8+(1/8*I)*sqrt(79)))^(-1)*(1/8+(1/8*I)*sqrt(79))^3); {-1264*d,-1264} > numer_denom((-(4/79*I)*(-1/8+(1/8*I)*sqrt(79))*sqrt(79)-(4/79*I)*(1/8+(1/8*I)*sqrt(79))*sqrt(79))*d-(3/79*I)*(1/8-(1/8*I)*sqrt(79))^2*sqrt(79)+(3/79*I)*(1/8+(1/8*I)*sqrt(79))^2*sqrt(79)-(4/79*I)*(-3/32-(3/32*I)*sqrt(79))*sqrt(79)-(4/79*I)*(3/32-(3/32*I)*sqrt(79))*sqrt(79)+(-(4/79*I)*(-1/32-(1/32*I)*sqrt(79))*sqrt(79)-(4/79*I)*(1/32-(1/32*I)*sqrt(79))*sqrt(79)+(4/79*I)*(1/8-(1/8*I)*sqrt(79))^2*sqrt(79)-(4/79*I)*(1/8+(1/8*I)*sqrt(79))^2*sqrt(79))*c-3/4*(-(1/8-(1/8*I)*sqrt(79))^2-(1/4*I)*sqrt(79)+(1/8-(1/8*I)*sqrt(79))*(1/8+(1/8*I)*sqrt(79)))^(-1)*(1/8-(1/8*I)*sqrt(79))^3+3/4*(-(1/8-(1/8*I)*sqrt(79))^2-(1/4*I)*sqrt(79)+(1/8-(1/8*I)*sqrt(79))*(1/8+(1/8*I)*sqrt(79)))^(-1)*(1/8-(1/8*I)*sqrt(79))-3/4*((1/8+(1/8*I)*sqrt(79))^2-(1/4*I)*sqrt(79)+(-1/8+(1/8*I)*sqrt(79))*(1/8+(1/8*I)*sqrt(79)))^(-1)*(1/8+(1/8*I)*sqrt(79))+3/4*((1/8+(1/8*I)*sqrt(79))^2-(1/4*I)*sqrt(79)+(-1/8+(1/8*I)*sqrt(79))*(1/8+(1/8*I)*sqrt(79)))^(-1)*(1/8+(1/8*I)*sqrt(79))^3); {1264*d,1264} > numer_denom((-(4/79*I)*(-1/8+(1/8*I)*sqrt(79))*sqrt(79)-(4/79*I)*(1/8+(1/8*I)*sqrt(79))*sqrt(79))*d-(3/79*I)*(1/8-(1/8*I)*sqrt(79))^2*sqrt(79)+(3/79*I)*(1/8+(1/8*I)*sqrt(79))^2*sqrt(79)-(4/79*I)*(-3/32-(3/32*I)*sqrt(79))*sqrt(79)-(4/79*I)*(3/32-(3/32*I)*sqrt(79))*sqrt(79)+(-(4/79*I)*(-1/32-(1/32*I)*sqrt(79))*sqrt(79)-(4/79*I)*(1/32-(1/32*I)*sqrt(79))*sqrt(79)+(4/79*I)*(1/8-(1/8*I)*sqrt(79))^2*sqrt(79)-(4/79*I)*(1/8+(1/8*I)*sqrt(79))^2*sqrt(79))*c-3/4*(-(1/8-(1/8*I)*sqrt(79))^2-(1/4*I)*sqrt(79)+(1/8-(1/8*I)*sqrt(79))*(1/8+(1/8*I)*sqrt(79)))^(-1)*(1/8-(1/8*I)*sqrt(79))^3+3/4*(-(1/8-(1/8*I)*sqrt(79))^2-(1/4*I)*sqrt(79)+(1/8-(1/8*I)*sqrt(79))*(1/8+(1/8*I)*sqrt(79)))^(-1)*(1/8-(1/8*I)*sqrt(79))-3/4*((1/8+(1/8*I)*sqrt(79))^2-(1/4*I)*sqrt(79)+(-1/8+(1/8*I)*sqrt(79))*(1/8+(1/8*I)*sqrt(79)))^(-1)*(1/8+(1/8*I)*sqrt(79))+3/4*((1/8+(1/8*I)*sqrt(79))^2-(1/4*I)*sqrt(79)+(-1/8+(1/8*I)*sqrt(79))*(1/8+(1/8*I)*sqrt(79)))^(-1)*(1/8+(1/8*I)*sqrt(79))^3); {1264*d,1264} > numer_denom((-(4/79*I)*(-1/8+(1/8*I)*sqrt(79))*sqrt(79)-(4/79*I)*(1/8+(1/8*I)*sqrt(79))*sqrt(79))*d-(3/79*I)*(1/8-(1/8*I)*sqrt(79))^2*sqrt(79)+(3/79*I)*(1/8+(1/8*I)*sqrt(79))^2*sqrt(79)-(4/79*I)*(-3/32-(3/32*I)*sqrt(79))*sqrt(79)-(4/79*I)*(3/32-(3/32*I)*sqrt(79))*sqrt(79)+(-(4/79*I)*(-1/32-(1/32*I)*sqrt(79))*sqrt(79)-(4/79*I)*(1/32-(1/32*I)*sqrt(79))*sqrt(79)+(4/79*I)*(1/8-(1/8*I)*sqrt(79))^2*sqrt(79)-(4/79*I)*(1/8+(1/8*I)*sqrt(79))^2*sqrt(79))*c-3/4*(-(1/8-(1/8*I)*sqrt(79))^2-(1/4*I)*sqrt(79)+(1/8-(1/8*I)*sqrt(79))*(1/8+(1/8*I)*sqrt(79)))^(-1)*(1/8-(1/8*I)*sqrt(79))^3+3/4*(-(1/8-(1/8*I)*sqrt(79))^2-(1/4*I)*sqrt(79)+(1/8-(1/8*I)*sqrt(79))*(1/8+(1/8*I)*sqrt(79)))^(-1)*(1/8-(1/8*I)*sqrt(79))-3/4*((1/8+(1/8*I)*sqrt(79))^2-(1/4*I)*sqrt(79)+(-1/8+(1/8*I)*sqrt(79))*(1/8+(1/8*I)*sqrt(79)))^(-1)*(1/8+(1/8*I)*sqrt(79))+3/4*((1/8+(1/8*I)*sqrt(79))^2-(1/4*I)*sqrt(79)+(-1/8+(1/8*I)*sqrt(79))*(1/8+(1/8*I)*sqrt(79)))^(-1)*(1/8+(1/8*I)*sqrt(79))^3); {-1264*d,-1264} > There are two problems here: (1) the numerator and denominator returned are trivially not coprime; and (2) numer_denom does not behave like a mathematical function. With the same input, it produces the sequence of answers {-1264*d,-1264} {-1264*d,-1264} {1264*d,1264} {-1264*d,-1264} {-1264*d,-1264} {1264*d,1264} {-1264*d,-1264} {1264*d,1264} {1264*d,1264} {-1264*d,-1264} All the best Roberto -- Prof. Roberto Bagnara Computer Science Group Department of Mathematics, University of Parma, Italy http://www.cs.unipr.it/~bagnara/ mailto:bagnara@cs.unipr.it

2 1

how to do subs for symmetric indexed objects?
by Yong Xiao 27 Jun '03

27 Jun '03

Hello, I am tring to substitute Y_{imn}t_{nj} by Y_{jmn}t_{ni} where Y is a symmetric indexed object. My code for this is like indexed(Y,sy_symm(),i_,m_,n_)*indexed(t,n_,j_) ==indexed(Y,sy_symm(),j_,n_,m_)*indexed(t,n_,i_) where i_,j_,m_ and n_ are wildcards. But the code doesn't work. Attached is the code. How should I do? Thanks #include <iostream> #include <ginac/ginac.h> using namespace std; using namespace GiNaC; int main() { symbol Y("Y"),t("t"); symbol i_sym("i"),j_sym("j"),m_sym("m"),n_sym("n"); idx i(i_sym,3),j(j_sym,3),m(m_sym,3),n(n_sym,3); wildcard i_(0),j_(1),m_(2),n_(3); ex e1 = indexed(Y,sy_symm(),i,m,n)*indexed(t,n,j); e1 = e1.subs(indexed(Y,sy_symm(),idx(i_,3),idx(m_,3),idx(n_,3)) *indexed(t,idx(n_,3),idx(j_,3)) ==indexed(Y,sy_symm(),idx(j_,3),idx(n_,3),idx(m_,3)) *indexed(t,idx(n_,3),idx(i_,3)), subs_options::subs_algebraic); cout << e1 << endl; return 0; }

2 1

GiNaC 1.1.1 released
by Christian Bauer 18 Jun '03

18 Jun '03

Hi! With one last-minute bug-fix sneaked in by the ever-helpful Chris Dams, we'd like to present GiNaC 1.1.1 which is crunchy on the outside but soft and delicious on the inside: - lst (and exprseq) provide iterators for read-only element access. For sequential access this is one order faster than using op(). - Implemented relational::subs() (this was done in 1.0.9 but inadvertently omitted from the 1.1 branch). - pole_error and do_taylor are available to library users. - Added on-line help and Tab-completion for print(), iprint(), print_latex() and print_csrc() in ginsh. Get it from your favorite FTP server: ftp://ftpthep.physik.uni-mainz.de/pub/GiNaC There's nobody here to drink champagne with, so I can save to money for buying more C++ books... Happy computing, Christian -- / Physics is an algorithm \/ http://www.uni-mainz.de/~bauec002/

1 0

Atoms of an expression
by Dr. Vassilis S. Vassiliadis 10 Jun '03

10 Jun '03

How is it possible to get GiNaC to yield all the atoms occuring in an expression? (i.e. return a list of all the leaves of the expression tree). This is of interest in the generation of sparse jacobian / hessian matrices as one example of applications. Vassilis ----------------------------------------------------------------- Dr. Vassilis S. Vassiliadis, Lecturer, UNIVERSITY OF CAMBRIDGE, DEPARTMENT OF CHEMICAL ENGINEERING Pembroke Street, Cambridge CB2 3RA, UK. e-mail: vsv20(a)cheng.cam.ac.uk -----------------------------------------------------------------

2 1

simplify_indexed() didn't fully simplify the expressions
by Yong Xiao 09 Jun '03

09 Jun '03

Hi! I am using GiNaC1.1.0 It seems that for some expression(suppose it's defined as e1) simplify_indexed() doesn't do simplification fully. However, if I define another ex objec tmp = e1, and e1.simplify_indexed() will give a more simple expression which, although, is still not of the simplest form. Anyone knows a more efficient way? Another problem I met is that when I simplify an expression which is composed of 240 terms, where every term is a simple product of indexed objects, the complilation will stop, saying "out of memory". I don't think that GiNaC can't handle such expressions. Anything wrong?

2 3

cln and compilation!
by Jean-Sebastien Gagne 28 Apr '03

28 Apr '03

Hello, I installed cln in private a dir and am trying to compile some basic c++ code using cl_I class. The problems is I am not able to get an executable out my code. The installation seems to have worked ok. I did not have any error and I can execute the examples. What woul be the correct command to get exe from my code? I known the -I and -l flags are involved but cannot get the right combo. I am a little new at this! Thanks! Jean-Sebastien Gagne

2 1

GiNaC 1.1.0 released
by Christian Bauer 04 Apr '03

04 Apr '03

Lo! Receive now, mylords, version 1.1 of GiNaC, as a gift from one who has nothing, and as a memorial of macros and print_contexts. For now our fate is fulfilled, and-- Oops, I think I got the wrong script here. Anyway... Today, we'd like to present GiNaC 1.1.0. This is the first release since 1.0.0 to introduce incompatible API changes (hence the "1" after the first dot), but unless you are extending GiNaC with your own algebraic classes you probably won't notice (be sure, though, to check the change log for a list of things to watch out for). So rejoice, noble ladies and lords, and behold its mighty features: - Added stream manipulators dflt, latex, python, python_repr, tree, csrc, csrc_float, csrc_double, csrc_cl_N, index_dimensions and no_index_dimensions to control the output format. [That's, like, the coolest thing, if you ask me. Lets you, like, say "cout << latex", and then anything you print will be, like, in LaTeX code. Totally smooth, man...] - subs() accepts an optional "options" argument. The option subs_option::subs_algebraic enables "smart" substitutions in products and powers. [Brought to you by Chris Dams (the real one, not his substitute).] - The scalar_products mechanism allows the specification of an index dimension. [What could be beyond height and width, depth and time?] - Added ex::to_polynomial(). [ex::to_rational()'s evil twin brother.] - Removed deprecated macros is_ex_a, is_ex_exactly_a and friends for good. [Begone, macros! Begone!] - Removed dirac_gamma6/7(). [That's a feature?] - Made the hashing more simple and efficient. [Or so Richy claims...] 'Tis time, methinks, to join the feast: ftp://ftpthep.physik.uni-mainz.de/pub/GiNaC Good night, Christian -- / Coding on PowerPC and proud of it \/ http://www.uni-mainz.de/~bauec002/

1 0