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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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[bug] pi example program does not report correct accuracy
by xt knight 28 Jul '07

28 Jul '07

This is a simple bug and it's reproducible on every machine. Using the pi example in libcln (./examples), type this: pi 5 3.1415927 is not 5 digits. pi 1 3.1416 is not 1 digit. https://bugs.launchpad.net/debian/+source/cln/+bug/128851 This bug reporter also mentions that it rounds the last number and that's not documented anywhere. Thank you for your time, xtknight

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Re: GiNaC-list Digest, Vol 29, Issue 1
by Jan Bos 25 Jul '07

25 Jul '07

Dear Richard, Thanks for the prompt reply. I'm no expert and not aware of LIA-3. Maybe you could give me a reference as where to obtain it? The reason I posted the question is that since GiNaC is embedded in C++ (beautiful concept by the way) it seems odd to have different definitions for the case at hand. Of course I can't oversee the consequences of a change, it would be convenient to code decisions based on the argument in a uniform way though. Best regards Jan Bos On Sun, 2007-07-22 at 12:00 +0200, ginac-list-request(a)ginac.de wrote: > Send GiNaC-list mailing list submissions to > ginac-list(a)ginac.de > > To subscribe or unsubscribe via the World Wide Web, visit > https://www.cebix.net/mailman/listinfo/ginac-list > or, via email, send a message with subject or body 'help' to > ginac-list-request(a)ginac.de > > You can reach the person managing the list at > ginac-list-owner(a)ginac.de > > When replying, please edit your Subject line so it is more specific > than "Re: Contents of GiNaC-list digest..." > > > Today's Topics: > > 1. atan2(0,-4) = -Pi? (Jan Bos) > 2. Re: atan2(0,-4) = -Pi? (Richard B. Kreckel) > > > ---------------------------------------------------------------------- > > Message: 1 > Date: Sat, 21 Jul 2007 21:24:57 +0200 > From: Jan Bos <jb68(a)xs4all.nl> > Subject: [GiNaC-list] atan2(0,-4) = -Pi? > To: ginac-list(a)ginac.de > Message-ID: <1185045897.9600.20.camel@jbos1> > Content-Type: text/plain > > Dear All, > > Is there a reason for GiNaC (or ginsh) to evaluate > atan2(0,-4) as -Pi instead of +Pi the definition used by for instance > C/C++? Looking at the code, inifcns_trans.cpp last shown case below, > explicitly states it should. Or can I expect it to be changed in the > future? > > static ex atan2_eval(const ex & y, const ex & x) > { > if (y.info(info_flags::numeric) && x.info(info_flags::numeric)) { > > if (y.is_zero()) { > > // atan(0, 0) -> 0 > if (x.is_zero()) > return _ex0; > > // atan(0, x), x real and positive -> 0 > if (x.info(info_flags::positive)) > return _ex0; > > // atan(0, x), x real and negative -> -Pi > if (x.info(info_flags::negative)) > return _ex_1*Pi; > } > > ... > > The code fragment is from version 1.3.7 > > best regards > > Jan Bos > > > > > > ------------------------------ > > Message: 2 > Date: Sun, 22 Jul 2007 01:16:38 +0200 > From: "Richard B. Kreckel" <kreckel(a)ginac.de> > Subject: Re: [GiNaC-list] atan2(0,-4) = -Pi? > To: GiNaC discussion list <ginac-list(a)ginac.de> > Message-ID: <46A293D6.9040301(a)ginac.de> > Content-Type: text/plain; charset=ISO-8859-1; format=flowed > > Dear Jan, > > Jan Bos wrote: > > Is there a reason for GiNaC (or ginsh) to evaluate > > atan2(0,-4) as -Pi instead of +Pi the definition used by for instance > > C/C++? Looking at the code, inifcns_trans.cpp last shown case below, > > explicitly states it should. Or can I expect it to be changed in the > > future? > > > > static ex atan2_eval(const ex & y, const ex & x) > > { > > if (y.info(info_flags::numeric) && x.info(info_flags::numeric)) { > > > > if (y.is_zero()) { > > > > // atan(0, 0) -> 0 > > if (x.is_zero()) > > return _ex0; > > > > // atan(0, x), x real and positive -> 0 > > if (x.info(info_flags::positive)) > > return _ex0; > > > > // atan(0, x), x real and negative -> -Pi > > if (x.info(info_flags::negative)) > > return _ex_1*Pi; > > } > > > > I don't suppose anybody lightly intends to change such definitions. :) > > Well, I looked in my notes and didn't find anything motivating that > choice for atan2. > > I recall that back when I wrote this, CLTL 2nd edition provided guidance > when choosing branch cuts of single-argument functions in the complex > domain. And later at some point I realized that the C99 standard agrees > with CLTL for all single-argument functions. (That appeared to be too > good to be true, but it is true.) Nobody was aware of LIA-3 at that time > but I'm quite sure that all of GiNaC's single-argument functions agree > with LIA-3, simply because they agree with C99. > > Our two-argument function atan2, however, may never have been checked > against any standard. I just did that with C99 and CLTL, and they both > specify atan2(0,-4) to be +Pi, indeed. Maybe, we ought to change this? > Before we do so: What does LIA-3 say? > > Our choice may be bad but I frankly admit that I don't know why +Pi is > any better than -Pi, or a more symmetric choice a la Mathematica like > atan2(0,x>0)=Pi/2, atan2(0,x<0)=-Pi/2, or 0 for all x. Can you explain > that choice? > > Cheers > -richy. > > PS: In any case, this is a good lesson how not to write comments, sigh. > -- > Richard B. Kreckel > <http://www.ginac.de/~kreckel/> > > > ------------------------------ > > _______________________________________________ > GiNaC-list mailing list > GiNaC-list(a)ginac.de > https://www.cebix.net/mailman/listinfo/ginac-list > > > End of GiNaC-list Digest, Vol 29, Issue 1 > ***************************************** >

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atan2(0,-4) = -Pi?
by Jan Bos 22 Jul '07

22 Jul '07

Dear All, Is there a reason for GiNaC (or ginsh) to evaluate atan2(0,-4) as -Pi instead of +Pi the definition used by for instance C/C++? Looking at the code, inifcns_trans.cpp last shown case below, explicitly states it should. Or can I expect it to be changed in the future? static ex atan2_eval(const ex & y, const ex & x) { if (y.info(info_flags::numeric) && x.info(info_flags::numeric)) { if (y.is_zero()) { // atan(0, 0) -> 0 if (x.is_zero()) return _ex0; // atan(0, x), x real and positive -> 0 if (x.info(info_flags::positive)) return _ex0; // atan(0, x), x real and negative -> -Pi if (x.info(info_flags::negative)) return _ex_1*Pi; } ... The code fragment is from version 1.3.7 best regards Jan Bos

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Expression order changing
by Martin Sandve Alnæs 05 Jun '07

05 Jun '07

Hi, when generating code from ginac expressions (with csrc), the order of the printed expressions will vary depending on previous operations in the program, in particular the previous construction of symbols. I understand this is because ginac uses an internal symbol id counter of some kind. Is it possible to "reset" this counter, or somehow make sure a set of newly created symbols keep the same relative order independent of previous operations in the program? It would save us a tremendous amount of recompilation and code verification if we could do this. -- --- Martin Sandve Alnæs PhD student, Cardiac Computations Simula Research Laboratory, Norway

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Problem simplifying exponents in polynomials
by Gerry Boland 05 Jun '07

05 Jun '07

Hi all, I'm fairly new to GiNaC, but it's most impressive so far. But I've a problem, I'm struggling to perform the following: I have a polynomial with lots of terms (beta,e,t1 & t2 are realsymbols) like: 1/6+1/36*e^(-beta)*e^t1*e^(-t1)+1/36*e^(-t1)*e^(-beta)*e^t1+ 25/36*e^t1*e^(-beta)*e^(-t1)-1/36*e^(-t1)-1/36*e^(-t1)- 1/36*e^t1*e^(-beta)-1/36*e^t1*e^(-beta)-1/36*e^(-beta)*e^t1+ 5/36*e^(-t1)-1/36*e^(-t1)+1/36*e^(-t1)*e^t1*e^(-beta)- 1/36*e^(-t1)+1/36*e^(-beta)*e^(-t1)*e^t1-1/36*e^(-beta)*e^t1- 1/36*e^(-beta)*e^t1+1/36*e^t1*e^(-t1)*e^(-beta)-1/36*e^(-t1)+ 5/36*e^t1*e^(-beta) which should simply evaluate to: 1/6+5/6*e^(-beta) I've not managed to make the expand() & collect() functions do this, it seems to not want to perform something like: e^t*e^(1-t)=e^1 I also tried this using actual exp() instead of e^ symbol, but I found it harder to collect terms then too. Is there something I'm missing or doing wrong? Many thanks in advance, -Gerry

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