- GiNaC-list - ginac.de

About CLN and GiNaC
by 777 threed 03 Nov '07

03 Nov '07

<ginac-list(a)ginac.de> Hello！ Recently I was interested in migrating the GiNaC from Unix to Windows, but I only need the symbolic operation not the large number operation, so I was wondering whether I can get rid of the CLN lib from the GiNaC, can any one tell me that where and how the GiNaC uses the CLN? Is it practicable that exclude the CLN lib? Best Regards! Daniel 2007-11-2

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Change precision of numeric
by Timo Schlüßler 03 Nov '07

03 Nov '07

Hello, how can I change the precision of a numeric? E.g. when I've got a numeric with 10,000 digits and then want that numeric truncated to 10 digits. I can't find anything in your tutorial, your reference nor via google. Thanks in advance, Timo

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indexed object
by Gilson Dallabona 02 Nov '07

02 Nov '07

Hi, I'm a new user of Ginac and I have found a problem. I need to define an indexed object with six indices or more. However, for an indexed object with more than four indices the compilation returns an error. A simple example is: symbol Delta("Delta"); varidx mu(symbol("mu"),4), nu(symbol("nu"),4), alpha(symbol("alpha"),4), beta(symbol("beta"),4), sigma(symbol("sigma"),4), lambda(symbol("lambda"),4); ex e = indexed(Delta,mu,nu,alpha,beta,alpha,beta); cout << e << endl; returns a compilation error like this "error: no matching function for call to 'GiNaC::indexed::indexed(GiNaC::symbol&, GiNaC::varidx&, GiNaC::varidx&, GiNaC::varidx&, GiNaC::varidx&, GiNaC::varidx&, GiNaC::varidx&)" Is there a way to define an indexed object with more than four indices in Ginac? Thanks, Gilson.

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new tinfo method makes is_a less efficient
by Diego Conti 13 Sep '07

13 Sep '07

Hi, I'm a mathematician and I find GiNaC very useful for doing calculations. Unfortunately, the new tinfo mechanism in version 1.4.0 breaks my code, and I am not sure how to fix that. Basically, what I need is an efficient version of is_a (actually, is_a<ncmul>) that does not rely on dynamic_cast. With the old tinfo method, I could simply redefine: template<> inline bool is_a<ncmul>(const basic & obj) { return (obj.tinfo()&TINFO_MASK)==TINFO_ncmul; } where TINFO_MASK is the constant 0x001fffffU, and the classes I derived from ncmul had appropriate tinfo constants. With the new method, where the tinfo_key is a pointer, the above code does not work. One obvious alternative is the following: struct tinfo_static_t <http://www.ginac.de/reference/structGiNaC_1_1tinfo__static__t.html> { const tinfo_static_t* derives_from; //NULL if derived from void, otherwise points to tinfo_static member in superclass <http://www.ginac.de/reference/structGiNaC_1_1tinfo__static__t.html> }; typedef const tinfo_static_t * tinfo_t; and then template <class T> inline bool is_a(const basic &obj) { const tinfo_static_t* tinfo=obj.tinfo(); do { if (tinfo==&T::tinfo_static) return true; tinfo = tinfo->derives_from <http://www.ginac.de/reference/structGiNaC_1_1tinfo__static__t.html>; } while (tinfo!=NULL); return false; } This appears reasonably efficient, but it will not work because, for instance, add::return_type_tinfo <http://www.ginac.de/reference/classGiNaC_1_1add.html#b2>() can return this, which can be converted to a pointer to void but not to a pointer to tinfo_static_t. I really do not understand the meaning of this choice. Can someone explain? What would I need to change in order to make the above code work? Thanks in advance Diego Conti

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Installation ginac(1.4) + cln(1.1.13) on powermac
by Hans-Jürgen Greif 11 Sep '07

11 Sep '07

Hi to all, because octave can't install symbolic package, I have tried to install ginac on powermac G4 v. 10.4.10. The ginac configure script ends with: checking for pkg-config... /sw/bin/pkg-config checking pkg-config is at least version 0.9.0... yes checking for CLN... configure: error: Package requirements (cln >= 1.1.6) were not met. Consider adjusting the PKG_CONFIG_PATH environment variable if you installed software in a non-standard prefix. Alternatively you may set the CLN_CFLAGS and CLN_LIBS environment variables to avoid the need to call pkg-config. See the pkg-config man page for more details. ________________________ I have no experience with pkg-config, so I decided to use environments variables bash shell: declare -x CLN_CFLAGS="-I/usr/local/include/cln" declare -x CLN_ LIBS="-L/usr/local/libs/ -lcln" for installed cln 1.1.13 which is definitely greater (newer) as 1.1.6. However, this does not work. Can anyone tell to me, how to set the variables above. Or can anyone give a pkg file to handle this problem? Sincerely, Hans-Jürgen Greif

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Installation ginac(1.4) +cln(1.1.3) on powermac
by Hans-Jürgen Greif 08 Sep '07

08 Sep '07

The system I use is (uname -a) Darwin alpha.local 8.10.0 Darwin Kernel Version 8.10.0: Wed May 23 16:50:59 PDT 2007; root:xnu-792.21.3~1/RELEASE_PPC Power Macintosh powerpc The config.log is attached. Regards, Hans-Jürgen Greif

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GiNaC release 1.4.0
by Jens Vollinga 31 Aug '07

31 Aug '07

Hello everybody, GiNaC 1.4.0 is out and available. The changes are: - New tinfo mechanism. - Removed rtt from class symbol. - Faster archiving by adding a map from strings to indices in the atoms vector. - Improved unarchiving: algorithms order N instead of order N^2. - Added compile function, excompiler class. - Added exset type. - Added step function to GiNaCs built-in functions. - Added is_polynomial() method. - Added real_part() and imag_part() methods. - Added matrix::is_zero_matrix() method. - Added evalm() method to pseries class. - Improved dummy index renaming. - Many improvements for class clifford. - New flag for positive symbols/numbers, added possymbol class. - Added programming examples in doc/examples *Note*: the tinfo mechanism has changed from fixed magic numbers to dynamically assigned tinfo-ids. If have written your own GiNaC classes, you need to adjust your code! As always, this release can be downloaded from http://www.ginac.de/Download.html Best wishes, Jens

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GiNaC release 1.3.8
by Jens Vollinga 28 Aug '07

28 Aug '07

Hello everybody, GiNaC 1.3.8 is out and available. The changes are: - Drop support of ginac-config and ginac.m4. Please use pkg-config instead. - atan2(y,x) branch cut correction. - Fixed bug in series expansion. - Additional transformations for mul and power. - Clifford units now honor representation labels. - Correct csrc output for idx and fderivative. - Improved handling of convergence transformationis for Li/G. - Fix compilation issues with prereleases of GCC 4.3. - info_flags::expanded added. - input_parser also accepts pow(). - texinfo.tex removed from package. As always, this release can be downloaded from http://www.ginac.de/Download.html Best wishes, Jens

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'Nice' output of GiNaC in C++ CGI
by Yigal Asnis 06 Aug '07

06 Aug '07

Hi, I'm building web site for interactive solving school math problems using GiNaC and cgicc. My question is how to output GiNaC's expressions into web-page in form of formatted formulae (image file) rather than one-row string. Thanks for your help in advance. Yigal. ____________________________________________________________________________________ Choose the right car based on your needs. Check out Yahoo! Autos new Car Finder tool. http://autos.yahoo.com/carfinder/

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dirac_slash(0) Does'nt work !!!
by J. gallardo 06 Aug '07

06 Aug '07

I'm trying to write an expression wich uses a Dirac " gamma 0 " for calculations on spin polarization projector, the line looks like: ex XAA=dirac_slash(0)* dirac_slash(k,4)*proj1* dirac_slash(E,4)* (dirac_slash(p,4)+ m * dirac_ONE()) * dirac_slash(E,4) * dirac_slash(k,4)*proj1* dirac_slash(E1,4) * (dirac_slash(p1,4)+m * dirac_ONE()); i'm not surethis is right, but I can't find other way to put a "gamma 0" in the expression... For instance I get the error: /usr/local/include/ginac/clifford.h: In function ‘int main()’: /usr/local/include/ginac/clifford.h:231: error: too few arguments to function ‘GiNaC::ex GiNaC::dirac_slash(const GiNaC::ex&, const GiNaC::ex&, unsigned char)’ QED_slasshes.cc:80: error: at this point in file what is wrong ? How I have to do it? Thanks. Jorge. -- View this message in context: http://www.nabble.com/dirac_slash%280%29-Does%27nt-work-%21%21%21-tf4167675… Sent from the Ginac - General mailing list archive at Nabble.com.

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