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Compiling Ginac with MinGW failed in Ginsh compile eventhough, I dont wish to compile it
by Christiand 03 Sep '12

03 Sep '12

Dear All, I am new user of Ginac. I am using mingw to for compiling to MSVC. I have succesfully reached several check point according to following link : http://sourceforge.net/apps/mediawiki/ooo-imath/index.php?title=Compiling_u… - Compile GMP -> succesful - Compile CLN -> succesful Now , I am in the step of compiling Ginac. The ./configure results : $ ./configure CC=cl CXX=cl CCAS=cl CXXFLAGS="-DDO_GINAC_ASSERT -ggdb -Wall -ped antic" CPPFLAGS="-DEBUG -MD -EHsc -I../vc/include -I../sdk/include -I../../vc/i nclude -I../../sdk/include -I/usr/local/cln" LIB=../vc/lib:../sdk/lib:../../vc/ lib:../../sdk/lib:/usr/local/lib PKG_CONFIG_PATH=/usr/local/lib/pkgconfig --dis able-shared --enable-static result : === The following minor problems have been detected by configure. === Please check the messages below before running "make". === (see the section 'Common Problems' in the INSTALL file) == ginsh will not compile, because libreadline could not be found. == Documentation may not build, because fig2dev/texinfo is missing. == Reference manual will not build, because doxygen is missing. == Some documentation formats may not build, because latex/pdflatex/dvips is mis sing. As suggested, if I don't want to compile (use) ginsh, I can safely neglect the the warning. However, I got error during make process. ginsh_parser.yy(888) : warning C4100: 'name' : unreferenced formal parameter ginsh_parser.yy(916) : error C3861: 'isatty': identifier not found ginsh_parser.yy(927) : fatal error C1083: Cannot open include file: 'ginsh_op_he lp.h': No such file or directory make[1]: *** [ginsh_parser.obj] Error 2 make[1]: Leaving directory `/mingw/msys/ginac-1.6.2/ginsh' make: *** [all-recursive] Error 1 I dont understand this error message to some extent. It is said that ginsh will not be compiled but why it still compile ginsh. Do I misunderstand the warning ? Please suggest me on this matter. Thanks Chris

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Symbolic Differentiation
by Diego Ariel Hollmann 22 Aug '12

22 Aug '12

Hello, I've seen a thread last month from Martin Ettl, and I'm having the same problem but the solution proposed by Jens Volling does not work for me. I need to derive expressions with variables that depend on others, for example: x(t)^2+sin(y(t)). I need to derive with respect to variable t. The solution proposed by Jens was: DECLARE_FUNCTION_1P(a) DECLARE_FUNCTION_1P(b) REGISTER_FUNCTION(a, dummy()) REGISTER_FUNCTION(b, dummy()) int main() { symbol t("t"); ex expr = a(t) * b(t); cout << expr << endl; cout << expr.diff(t,1) << endl; return 0; } This does not work with all kind of expressions, for example, with the one I wrote before... if I use this solution with: ex expr = a(t)^2 + sin(b(t)) it throws an error with the operator "^". Any idea how can I do this king of derivations? Thank you in advance! Diego H.

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Question regarding symbolic differentiation
by Martin Ettl 22 Jul '12

22 Jul '12

Hello, i have a question regarding symbolic differentiation with GiNAC. Here is what i am trying to do: I have to variables a(t) and b(t), both are dependent from time (t). Suppose, this two variables are multiplied liked this: a(t) * b(t) Is it possible to derive this expression (a(t)*b(t)) according time with ginac. The only function i found in the manual is usefull for partial derivation, which does not help me here. Here is some example code: symbol a("a"), b("b"); // <-- how to tell ginac that variable a and b is dependant from variable t expression f = a*b; std::cout << f.diff(t,1) << std::endl; Many thanks in advance and best regards Martin Ettl

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linking error with ginac example program derivative.cpp
by Robert Durkacz 17 Jul '12

17 Jul '12

I am just starting with ginac but unable to build the derivative.cpp program from doc/examples/ in ginac-1.6.2 Others of the examples that I tried were built successfully, eg compile1.cpp and compile3.exe I am using these versions of ginac and cln: cln-1.3.2 ginac-1.6.2 These libraries were built without problems as per INSTALL instructions. compiler (gcc --version): gcc (GCC) 3.4.4 (cygming special, gdc 0.12, using dmd 0.125) platform (uname -a): CYGWIN_NT-5.1 dell 1.7.15(0.260/5/3) 2012-05-09 10:25 i686 Cygwin command line of compile and link steps: g++ -c -Wall -g -I.. -I../ginac -DIN_GINAC -o gcc/derivative.o derivative.cpp g++ -o derivative gcc/derivative.o ../ginac/.libs/libginac.a /usr/local/lib/libcln.a -ldl ../ginac/.libs/libginac.a(parser.o): In function `_ZNSt16invalid_argumentD1Ev': /home/Owner/technical/ginac-1.6.2/ginac/parser/parser.h:46: multiple definition of `GiNaC::container<std::list>::info(unsigned int) const' ../ginac/.libs/libginac.a(lst.o):/usr/lib/gcc/i686-pc-cygwin/3.4.4/include/c++/bits/list.tcc:(.text+0x0): first defined here collect2: ld returned 1 exit status It is beyond my current abilities to sort out this problem. Could someone tell me what is going wrong?

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internal representation of expressions
by Felipe Bordeu 18 Apr '12

18 Apr '12

Hello, I'm trying to debug a program, and the problems is that the terms in a sum are not ordered in the same way in every run. for example : 1 run : A+B+C gives A+B+C 2 run : A+B+C gives C+B+A ... I know that the 2 expressions are equal but I will like GiNaC to represent the expression always in the same way. It's only for debugging so I don't care about performance. Thanks Felipe -- Felipe Bordeu Weldt Ingénieur de Recherche ------------------------------------- Tél. : 33 (0)2 40 37 16 57 Fax. : 33 (0)2 40 74 74 06 Felipe.Bordeu(a)ec-nantes.fr Institut GeM - UMR CNRS 6183 École Centrale Nantes 1 Rue de La Noë, 44321 Nantes, FRANCE -------------------------------------

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Using clang to build libraries - ginac and cln
by Fletcher, John P 07 Apr '12

07 Apr '12

I sent this to the Clang list, and am sending it here too as I see that GiNaC has been built with Clang. I want to build GiNaC with Clang 31 (SVN) and libc++ to work with code running under -std=c++0x Please let me know if there is somewhere where the makefile is described. Thanks John ________________________________________ From: Fletcher, John P Sent: 07 April 2012 00:11 To: cfe-dev(a)cs.uiuc.edu Subject: Using clang to build libraries - ginac and cln Hi I need to rebuild the libraries ginac and cln to work with clang31 libc++ and C++11. Is there a tutorial anywhere on how to build the makefile to do this? Thanks John

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Number representation
by Michel Dupront 29 Mar '12

29 Mar '12

Hello, I am new to ginac. At the moment I am playing with the tool trying to compute finite element bases as in SyFi. As a solution of a system of linear equations I got: {b0_0==0.25,b0_1==-0.25,b0_2==-0.25,b0_3==0.25} But I would have wanted the fraction 1/4 instead of 0.25. How can I force ginac to not compute fractions ? Thank in advance.

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converting expressions to double
by Tomasz I. Rudny 02 Mar '12

02 Mar '12

Hello, Thank you for GiNaC and your support - I have almost completed my PhD with it :) But I have a little problem still... I have a symbolic expression F(x, y, z, u) and I need to 1) substitute x, y, z, u with values (given as double), 2) calculate F, 3) export F as double. My code looks like this: double my_method(GiNaC::ex & ex, double x1, double y1, double z1, double u1) { numeric _x(x1), _y(y1), _z(z1), _u(u1); ex = ex.subs(lst(x == _x, y == _y, z == _z, u == _u)); ex = ex.evalf(); numeric tmp = ex_to<numeric>(ex); return tmp.to_double(); } Unfortunately, the last instruction (to_double() ) fails and throws the exception: terminate called after throwing an instance of 'cln::notreached_exception' what(): 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! I read the response cited below, but still I can't fix it. Could you please help me? Thank you very much, Tomasz. Warsaw University of Technology ========================= Hi! On 11/02/2010 08:12 AM, Sebastian Luther wrote: > below you'll find a small test program that crashes for me. > > -------------------------------------------- > #include<ginac/ginac.h> > #include<iostream> > > int main(int argc, char* argv[]) > { > GiNaC::parser p; > GiNaC::ex e = p("941480149401/1250000000000000*2^(5/91)"); > GiNaC::numeric n = GiNaC::ex_to<GiNaC::numeric>(e); > double x = n.to_double(); //throws the exception below > return 0; > } Since e is a product (of a rational number and a power of two) it must be converted to a number using evalf() before trying to assign it to a simple numeric object. > Looks like the real problem lays in cln, but I'm not sure how to reproduce it there. It has nothing to do with CLN. Best wishes -richy. -- Richard B. Kreckel <http://www.ginac.de/~kreckel/>

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How to convert epsilon_tensor in a matrix?
by Marco André Ferreira Dias 26 Feb '12

26 Feb '12

Hi, I have a very naive question: my program compute some dirac_traces, and some epsilon_tensors arises in this process. I have to convert the tensorial structure to matricial to compute it numerically, but until now I don't figure out how to manipulate expressions like this ============= [[31],[0.0],[0.0],[-31]]~sigma*[[6.3],[0.0],[0.0],[6.30]]~alpha*[[19.33],[-1.108],[-5.4],[18.6]].gamma*eps.delta.sigma~gamma.alpha*[[16.781197650788506337],[4.96],[11.38],[11.2]]~gamma ============= Note that the episilon tensor is fully contracted by four (4x1) vectors. I will be glad for any suggestion given! Regards, Marco

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Simplifying a hierarchy of rational powers on positive symbols
by DerManu＠WorksLikeClockwork.com 21 Feb '12

21 Feb '12

Hi GiNaC Gurus, Consider the following expression: (2^(2/3)*x^2)^(3/2) where x is positive. I'd expect eval() to reduce this to 2*x^3, but it happens only, when calling evalf(). However, I'd like other possible parts of the expression to stay exact, so evalf() isn't an option. Here's the code for the above expression: possymbol x("x"); ex e = power( power(2,numeric(2)/numeric(3)) * power(x, 2) , numeric(3)/numeric(2) ); std::cout << e.eval() << " " << e.evalf() << std::endl; // I know eval is redundant, but it adds a dramatic element ;) Note this situation is somewhat related yet much simpler than Topic [1] because we're dealing with purely numeric powers here. Still it seems, this kind of simplification is just not wanted. Is that correct? Or is there a trick to make it all work easily? Would it be a sensible approach to write a map_function functor that grabs all powers that have positive muls as base and apply the power to all mul ops individually? Best regards, Emanuel [1] http://www.ginac.de/pipermail/ginac-list/2011-December/001862.html

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