December 2006 - GiNaC-list

(const) ostream&
by Harald Devos 27 Dec '06

27 Dec '06

Hi, the print functions declared in ginac/print.h all take "std::ostream &" as an argument. I wonder if this could be changed to "const std::ostream &". Else functions receiving a "const std::ostream &" (in any program using the GiNaC library) cause troubles when calling the print functions of the ginac library. Kind regards and best wishes for 2007. Harald Devos. -------------------------------------------------------------------------- Harald Devos Electronics and Information Systems Department, Faculty of Engineering, Ghent University, St. Pietersnieuwstraat 41, O O B-9000 Ghent, Belgium O O work phone: +32-9-264.34.51 fax: +32-9-264.35.94 O email: hmdevos(a)elis.UGent.be

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Serialization of datatypes
by Eric Collins 23 Dec '06

23 Dec '06

Would anyone be interested in helping me figure out how to serialize the datatypes in GiNaC/CLN/GMP? I've looked at the source headers for some of the datatypes and the use of reference counted pointers everywhere makes this seem like a non-trivial task. I need to be able to pack all data relevant to a particular instantiation of a datatype (e.g. numeric or pseries), into a contiguous array. This data would then be passed to another process where it would be unpacked into a new instantiation of the same datatype. Any help, or suggestions of where to begin looking for relevant information would be much appreciated. Eric M. Collins -- Ad Astra Per Aspera

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Release of GiNaC 1.3.6
by Jens Vollinga 13 Dec '06

13 Dec '06

Hello everybody, GiNaC 1.3.6 is out and available. The changes are: - Better worst case behavior in heuristic gcd. - Improved collecting for sparse multivariate polynomials. - Improved collect_common_factors. - Fixed bug in numerical evaluation of multiple polylogs. - Fixed numerical integration of complex functions. - Fixed bug in tensor::replace_contr_index(). As always, this release can be downloaded from http://www.ginac.de/Download.html Best wishes, Jens

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Internal error: statement in file ./real/conv/cl_R_to_double.cc, line 55 has been reached!!
by Pedro Cruz 08 Dec '06

08 Dec '06

Hi, -------------------- this output -------------------- Pi=3.1415926535897932385 Internal error: statement in file ./real/conv/cl_R_to_double.cc, line 55 has been reached!! Please send the authors of the program a description how you produced this error! -------------------- has been produced by -------------------- #include <iostream> #include <sstream> #include <stdexcept> #include <ginac/ginac.h> using namespace std; using namespace GiNaC; int main() { cout << "Pi=" << Pi.evalf() << endl; if (is_a<constant>(Pi)) { double f = ex_to<numeric>(Pi).to_double(); cout << f << endl; } return 0; } --------------------------------------------- on debian (etch testing) with libginac1.3c2a. --------------------------------------------- It was a first example i tried to do in order to understand ginac/cln concepts: <ex> <constant> and <numeric>. How to convert from Pi to C++ double type in one C++ line ? Thanks, Pedro Cruz

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GiNaC as a polynomials manipulator?
by Francesco Biscani 03 Dec '06

03 Dec '06

Hello, I'd like to know if GiNaC can be used as a polynomials manipulator for celestial mechanics. It's needed to multiplicate and add polynomials by polynomials. An important requisite is to be able to extract the degree of the monomials in order to decide whether that particular monomial should be eliminated from the polynomial or not. Example: x^2*y+x^2*y^2+x^3*z If the truncation threshold is set to order 4 this polynomial gets truncated to x^2*y I imagine that a function to place polynomials in some kind of "canonical" form is needed, and then it is needed to inspect each monomial to see if it will be kept or not. Is this possible with GiNaC? Thanks and best regards, Francesco

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Fwd: compute groebner basis?
by fabian＠fseoane.net 03 Dec '06

03 Dec '06

Hello! I'm new to GiNaC and my question is: Has GiNaC got a routine to compute Groebner basis? If the answer is no, then if i tried to implement one, would it be welcome ? Greetings ------------- Fabian

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