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Collect() with a list of variables doesn't work in ginsh
by Vitaly Magerya 24 Mar '21

24 Mar '21

Hi, all. In section 5.7.2 of the docs (Expanding and collecting) there is this example of ginsh usage: > a=expand((sin(x)+sin(y))*(1+p+q)*(1+d)); > collect(a,{p,q}); The docs say I should get this: d*sin(x)+(d*sin(x)+sin(y)+d*sin(y)+sin(x))*p ... but actually: cannot modify multiply referenced object This is with GiNaC V1.7.6, V1.7.8, and the latest commit of V1.8.0. How do I make this work?

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Differentiate matrix wrt vector
by Orxan Shibliyev 04 Mar '21

04 Mar '21

Suppose, I have a 5x5 matrix and I want to differentiate the matrix wrt to a 5x1 matrix in order to obtain a 3D matrix or tensor. In the following code, A.diff(uL); cannot compile. Is it possible to differentiate a matrix with symbolic elements wrt to a vector which also contains symbols? #include <iostream> #include <ginac/ginac.h> using namespace std; using namespace GiNaC; int main() { const int DIM = 5; symbol g("g"); symbol uL1("uL1"); symbol uL2("uL2"); symbol uL3("uL3"); symbol uL4("uL4"); symbol uL5("uL5"); matrix uL = { {uL1}, {uL2}, {uL3}, {uL4}, {uL5} }; auto qL = matrix(DIM, 1); qL(0,0) = sqrt(uL1); qL(1,0) = uL2 / qL(0,0); qL(2,0) = uL3 / qL(0,0); qL(3,0) = uL4 / qL(0,0); qL(4,0) = (uL5 + (g - 1) * (uL5 - 0.5 * (pow(uL2,2) + pow(uL3,2) + pow(uL4,2)) / uL1)) / uL1; symbol uR1("uR1"); symbol uR2("uR2"); symbol uR3("uR3"); symbol uR4("uR4"); symbol uR5("uR5"); matrix uR = { {uR1}, {uR2}, {uR3}, {uR4}, {uR5} }; auto qR = matrix(DIM, 1); qR(0,0) = sqrt(uR1); qR(1,0) = uR2 / qR(0,0); qR(2,0) = uR3 / qR(0,0); qR(3,0) = uR4 / qR(0,0); qR(4,0) = (uR5 + (g - 1) * (uR5 - 0.5 * (pow(uR2,2) + pow(uR3,2) + pow(uR4,2)) / uR1)) / uR1; auto q = qL.add(qR); q.mul_scalar(0.5); matrix B = { {2*q(0,0), 0, 0, 0, 0}, {q(1,0), q(0,0), 0, 0, 0}, {q(1,0), q(0,0), 0, 0, 0}, {q(2,0), 0, q(0,0), 0, 0}, {q(3,0), 0, 0, q(0,0), 0}, {q(4,0)/g, (g-1)*q(1,0)/g, (g-1)*q(2,0)/g, (g-1)*q(3,0)/g, q(0,0)/g} }; matrix C = { {q(1,0), q(0,0), 0, 0, 0}, {(g-1)*q(4,0)/g, (g+1)*q(1,0)/g, (1-g)*q(2,0)/g, (1-g)*q(3,0)/g, (g-1)*q(0,0)/g}, {0, q(2,0), q(1,0), 0, 0}, {0, q(3,0), 0, q(1,0), 0}, {0, q(4,0), 0, 0, q(1,0)} }; auto A = B.mul(C.inverse()); A.diff(uL); return 0; }

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Some problem Installing GiNaC on Linux
by 이재욱 16 Jan '21

16 Jan '21

Hello GiNac-list, I have some problems installing the GiNaC on Linux. May I ask you for advice? I followed the tutorial PDF to install, and the linux computer showed a message that "See check/test-suite.log Please report to ginac-list(a)ginac.de ". So, I sent an email to get some advice. I have the below prerequisite software version. $ g++ --version : 4.8.5 $ git --version : 1.8.3.1 $ autoconf --version : 2.69 $ libtool --version : 2.4.6 $ automake --version : 1.13.4 These files are in the '/usr/bin/' and I will install the GiNaC in the '/home/{USERNAME}/Package/' (I think these points make some problems.) First, I install the CLN before installing the GiNaC. $ ./configure --prefix=/home/{USERNAME}/Package $ make $ make check (--> all Pass) $ make install And then, I try to install the GiNaC $ export PKG_CONFIG_PATH=/home/{USERNAME}/Package/lib/pkgconfig $ ./configure --prefix=/home/{USERNAME}/Package $ make $ make check (--> there are 7 fail, and 51 PASS; it shows me the above message) Related log file(test-suite.log) is attached, I do not know what is wrong. Please let me help to install GiNaC well Thanks, ljw.

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cln::notreached_exception
by Dario Pellegrini 05 Jan '21

05 Jan '21

I am on v1.8.0, I have no experience with older versions. This trivial program results in a cln::notreached_exception being thrown. #include <ginac/ginac.h> > int main() { > GiNaC::ex a = GiNaC::Pi; > GiNaC::ex b = 1; > std::cout << GiNaC::ex_to<GiNaC::numeric>(a+b).to_double() << std::endl; > return 0; > } Compiled with: g++ test.cpp -lginac -lcln Here is the full exception message: what(): Internal error: statement in file real/conv/cl_R_to_double.cc, > line 48 has been reached!! > Please send the authors of the program a description how you produced this > error! I would expect that to work, am I wrong?

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cannot compile cpp code that uses GiNaC on Mac OS 10.15.7 (Catalina)
by Di Gi 20 Dec '20

20 Dec '20

Hello, I'm trying to compile cpp code that depends on GiNaC. The code is in this file: https://arxiv.org/src/1912.09099v1/anc/GPLs.cpp and I tried compiling it with the following command: g++ -std=c++11 GPLs.cpp -o GPLs.out -w -lcln -lginac I tried several alternatives for the -std option, but c++11 is the one producing the smallest amount of errors. The output I get is in the attached GPLs.log file. My OS is Mac OS Catalina (10.15.7). My compiler options are as follows: Configured with: --prefix=/Applications/Xcode.app/Contents/Developer/usr --with-gxx-include-dir=/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/c++/4.2.1 Apple clang version 12.0.0 (clang-1200.0.32.21) Target: x86_64-apple-darwin19.6.0 Thread model: posix InstalledDir: /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin I get the very same errors if I use the GNU compiler, but I understand that, under Mac, g++ = gcc = clang. I installed GiNaC through homebrew, and this is the version I have: ginac: stable 1.8.0 (bottled) Not a Computer algebra system https://www.ginac.de/ /usr/local/Cellar/ginac/1.8.0 (66 files, 8.9MB) * Poured from bottle on 2020-12-19 at 16:28:49 From: https://github.com/Homebrew/homebrew-core/blob/HEAD/Formula/ginac.rb License: GPL-2.0 ==> Dependencies Build: pkg-config ✔ Required: cln ✔, python(a)3.9 ✔, readline ✔ I had also tried to install GiNaC as well as CLN from git, but I get similar errors. I inspected GiNaC's lst header (the constructor producing the errors) but I cannot find anything wrong with it. Any help is greatly appreciated. Beste Grüße, Diego

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GiNaC 1.8.0 released
by Richard B. Kreckel 15 Oct '20

15 Oct '20

Hi, GiNaC 1.8.0 has just been tagged. Here are the news: * New routines for the numerical evaluation of iterated integrals like elliptic multiple polylogarithms or iterated integrals of modular forms. * Stronger normalization methods for expressions with powers. Where this is safe, GiNaC now tries replacing various kinds of powers in order to find and cancel common subexpressions. * Improved CMake build. Stay healthy, and happy hacking! -richy. -- Richard B. Kreckel <https://in.terlu.de/~kreckel/>

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Release 1.7.11
by Richard B. Kreckel 03 Aug '20

03 Aug '20

Hi, GiNaC 1.7.11 contains some bugfixes. Upgrade, if you can! :-) Take care! -richy. -- Richard B. Kreckel <https://in.terlu.de/~kreckel/>

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issue about series involving positive symbol
by Feng Feng 28 Jul '20

28 Jul '20

Hi all, I come across an issue about the series on an expression involving positive symbol, i.e., possymbol in GiNaC. the problem can be reproduced by the following program (test.cpp), for example, we compile the test.cpp to test, and then run the test program several times, we will see different outputs. for example, we can run the bash script in the terminal: for n in {1..20}; do ./test; done PS: if we change the possymbol to symbol in the test.cpp, we will always get correct result. Best regards! Feng --- #include "ginac/ginac.h" using namespace std; using namespace GiNaC; int main() { possymbol t("t"); symbol m("m"), ep("ep"); symtab table; table["ep"] = ep; table["t"] = t; table["m"] = m; parser reader(table); ex in1 = reader("(-3/2*t^2*(2*t*m^2-3*m^2*(-1+t))^(-1)*(-1+t)^(-1))"); ex in2 = reader("((3*pow(m,-2)*pow(-3+t,-1)*pow(-1+t,-1)*pow(t,2))/2)"); cout << "in1-in2 = " << normal(in1-in2) << endl; in1 = pow(in1,-1+ep)*tgamma(ep); in2 = pow(in2,-1+ep)*tgamma(ep); ex diff = series_to_poly(series(in1-in2,ep,1)); lst repl = lst{ep==2,m==1,t==1/ex(3)}; cout << "diff = " << normal(diff.subs(repl)) << endl; return 0; }

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Sqrfree_parfrac Issue GiNaC
by Konstantin Leyde 24 Jul '20

24 Jul '20

Hello, My name is Konstantin Leyde, and I am a master student in physics at the ETH Zurich. For my thesis project, I have been working with the GiNaC library, and I have encountered an issue with the partial fractioning (sqrfree_parfrac) routine: Unless I misunderstood the way the sqrfree_parfrac routine works, it appears that for special cases, the output of the sqrfree_parfrac routine misses a numerical prefactor for one term, and thus returns the wrong answer. Please find attached a pdf, that explains the problem in more detail. In this pdf (as well as separately) we have attached the code that shows the issue. Many thanks in advance, Best wishes, Konstantin

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Release 1.7.10
by Richard B. Kreckel 28 Jun '20

28 Jun '20

Hi, GiNaC 1.7.10 has just been released. The changes are: * Fix collect_common_factors() for hidden zero arguments. * Fix build on modern systems (C++20 and Python3). Take care! -richy. -- Richard B. Kreckel <https://in.terlu.de/~kreckel/>

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