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How can I get the values of the solved vars from the returned expression from lsolve?
by Zach 12 Oct '12

12 Oct '12

Hi I stumbled across this incredibly useful library and I wanted to use the lsolve function. I was reading the tutorial pdf to figure out how to use it. So from lsolve i end up with an expression like: *{a==3,b==4} > * I was wondering how I could get a value of the a and b symbols from this? I would ideally like to store them in an int to use in another library. I have been looking for an answer for a while so I would really appreciate if anyone knows? I could parse it like a string but Im assuming there is a better way? Thank you for your time, Zach

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Invitación para conectarse en LinkedIn
by Jose Antonio Garcia Peiro 19 Sep '12

19 Sep '12

LinkedIn ------------ Me gustaría añadirte a mi red profesional en LinkedIn. -Jose Antonio Jose Antonio Garcia Peiro Estudiante de Universidad Miguel Hernández de Elche Murcia y alrededores, España Confirma que conoces a Jose Antonio Garcia Peiro: https://www.linkedin.com/e/-qmwzwc-h79z92jy-5r/isd/4281101300/r-1XX1c3/?hs=… -- Estás recibiendo invitaciones a conectar. Haz clic para darte de baja: http://www.linkedin.com/e/-qmwzwc-h79z92jy-5r/kGy7Yg-6HHAoBPMg-Y4n5eWUQMwWs… (c) 2012 LinkedIn Corporation. 2029 Stierlin Ct, Mountain View, CA 94043, EE.UU.

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Possible bug in csrc output format.
by Javier Ros 12 Sep '12

12 Sep '12

Hi, I've been exporting C code from GiNaC using "csrc_double" output format during a long time. Now we are dealing with rather long real expressions, that involve only +-*\ and pow. In a benchmark and for comparison purposes we've end up comparing the results of evaluate the same function through "dflt" (used to generate output for MATLAB) and csrc_double (used to generate same code for C). Numerical discrepancies where found and traced back to to small symbolic differences in the output obtained through both formats. To avoid the problem and due to the symbolical simplicity of our expressions (only +-*\ and pow) we've developed our own -very simple- exporting format for C. Basically we derive our format from "dflt" and change the way in which natural numbers and powers are written (we append a .0 to natural numbers) and we change a^b with pow(a,b). Right now we are obtaining a correct behaviour the export based on our new format, coherent with "dflt" numerical results (in a particular case), and obtaining different results with csrc_double (I think too with csrc alone). So I think I'm facing a bug in csrc output format. I wonder if anybody wants me to report further on this (I don't feel confident as to dig into GiNaC's implementation of crsc). If so please let me know the way in which I can report back the error (or what I think is an error) with the required detail. Cheers, Javier

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Re: [GiNaC-list] Compiling Ginac with MinGW failed in Ginsh compile eventhough, I dont wish to compile it
by Christiand 04 Sep '12

04 Sep '12

Hi all, Thanks for your helps. First of all, I am actually super duper new in linux things and cross compiling, so frankly I don't understand about all things that I did, including also the commands for compiler and configure. I gathered all those by searching internet and reading some forums and just "try and error". My final goal is to compile ginac so that I have *.lib (static) or *.dll (shared) in to use in MSVC. That what brought me to that website link. I tried to follow all the steps with correction necessary according to my situation. As far as understand, CC=cl CXX=cl CCAS=cl is necessary if we want to compile library with cl.exe (microsoft compiler and linker), of course CC = cl shows that intention. I dont understand for the remaining two. That is the reason I put those options in configure. As said previously, missing in installing libreadline make error in ginsh compiling process. I am aware of that issue. However, (as i asked initially) I just dont get it when it is said that ginsh will not be compiled but in fact it is being compiled. I finally managed this problem by manually edit the makefile. I erased ginsh doc tool option in SUBDIRS = ginac check ginsh tools doc DIST_SUBDIRS = ginac check ginsh tools doc becoming SUBDIRS = ginac check DIST_SUBDIRS = ginac check then ginac is compiled succesfully. All tests are passed too. Now, I get the *.lib, I tested it in visual studio, It works well in release mode but not in debug. I dont know why. I am also trying to make *.dll. It is succesfully compiled, but all tests are failed. Again, I dont know what is the reason. related to Jan's suggestion about putting in .ll ( is it ginsh_lexer.ll ??), it is failed. Same error appeared. #ifdef _MSC_VER #define YY_NO_UNISTD_H #endif about alex Here is my setting : environment : msys (MinGW) compiler : cl ginac : ginac-1.6.2 cln : cln-1.3.2 gmp : gmp-5.0.5 XP ~ chris ~

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Re: [GiNaC-list] GiNaC-list Digest, Vol 82, Issue 2
by Christiand 04 Sep '12

04 Sep '12

Hi all, Thanks for your helps. First of all, I am actually super duper new in linux things and cross compiling, so frankly I don't understand about all things that I did, including also the commands for compiler and configure. I gathered all those by searching internet and reading some forums and just "try and error". My final goal is to compile ginac so that I have *.lib (static) or *.dll (shared) in to use in MSVC. That what brought me to that website link. I tried to follow all the steps with correction necessary according to my situation. As far as understand, CC=cl CXX=cl CCAS=cl is necessary if we want to compile library with cl.exe (microsoft compiler and linker), of course CC = cl shows that intention. I dont understand for the remaining two. That is the reason I put those options in configure. As said previously, missing in installing libreadline make error in ginsh compiling process. I am aware of that issue. However, (as i asked initially) I just dont get it when it is said that ginsh will not be compiled but in fact it is being compiled. I finally managed this problem by manually edit the makefile. I erased ginsh doc tool option in SUBDIRS = ginac check ginsh tools doc DIST_SUBDIRS = ginac check ginsh tools doc becoming SUBDIRS = ginac check DIST_SUBDIRS = ginac check then ginac is compiled succesfully. All tests are passed too. Now, I get the *.lib, I tested it in visual studio, It works well in release mode but not in debug. I dont know why. I am also trying to make *.dll. It is succesfully compiled, but all tests are failed. Again, I dont know what is the reason. related to Jan's suggestion about putting in .ll ( is it ginsh_lexer.ll ??), it is failed. Same error appeared. #ifdef _MSC_VER #define YY_NO_UNISTD_H #endif about alex Here is my setting : environment : msys (MinGW) compiler : cl ginac : ginac-1.6.2 cln : cln-1.3.2 gmp : gmp-5.0.5 XP ~ chris ~

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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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