April 2015 - GiNaC-devel

04 Jun '15

Hi, is there any reason not to define the derivative of the built-in abs() function as either abs(x)/x or csgn(x) ? Currently it has not derivative defined at all. Regards, Jan

5 8

Re: [GiNaC-devel] [GiNaC-list] Symbolic Integration of exponential functions
by Vladimir V. Kisil 27 Apr '15

27 Apr '15

Dear All, What is easy to do is to add to function class a primitive feature analogously to their knowledge of derivatives. Then, integral::eval_integ() may call such methods to evaluate simple integrals of plain functions. If this looks reasonable to be included in GiNaC, then I may write such a patch. Best wishes, Vladimir -- Vladimir V. Kisil http://www.maths.leeds.ac.uk/~kisilv/ Book: Geometry of Mobius Transformations http://goo.gl/EaG2Vu Software: Geometry of cycles http://moebinv.sourceforge.net/ >>>>> On Sat, 14 Mar 2015 17:35:10 +0100, Matthias Reis <matthias.reis(a)biologie.hu-berlin.de> said: MR> Dear all, as far as I understand, ginac cannot integrate MR> anything other than polynomials. How hard would it be (for me MR> maybe) to implement exponentials? What needs to be done? This MR> feature would be great for me. I just need to integrate simple MR> e^{x * constant} terms. MR> Best regards, Matthias

2 1

[SCM] GiNaC -- a C++ library for symbolic computations branch, master, updated. release_1-4-0-450-g84e6538
by git＠ginac.de 23 Apr '15

23 Apr '15

This is an automated email from the git hooks/post-receive script. It was generated because a ref change was pushed to the repository containing the project "GiNaC -- a C++ library for symbolic computations". The branch, master has been updated via 84e6538290cbd2b13b755254c62689a404ce91b4 (commit) from 43e31c593da10e6bf3c726236d3d794bc428bd3c (commit) Those revisions listed above that are new to this repository have not appeared on any other notification email; so we list those revisions in full, below. - Log ----------------------------------------------------------------- commit 84e6538290cbd2b13b755254c62689a404ce91b4 Author: Richard Kreckel <kreckel(a)ginac.de> Date: Thu Apr 23 22:33:52 2015 +0200 Add test cases for improved abs(arg). Exam the evaluations abs(±sqrt(p)) -> sqrt(p) for p > 0. ----------------------------------------------------------------------- Summary of changes: check/exam_inifcns.cpp | 6 ++++++ 1 file changed, 6 insertions(+) hooks/post-receive -- GiNaC -- a C++ library for symbolic computations

1 0

[SCM] GiNaC -- a C++ library for symbolic computations branch, master, updated. release_1-4-0-449-g43e31c5
by git＠ginac.de 22 Apr '15

22 Apr '15

This is an automated email from the git hooks/post-receive script. It was generated because a ref change was pushed to the repository containing the project "GiNaC -- a C++ library for symbolic computations". The branch, master has been updated via 43e31c593da10e6bf3c726236d3d794bc428bd3c (commit) via 0f7f5c00470b6f1d10b668e3a7b34438ed005d0f (commit) via 62168ea93d23c81172ad07f9ec2f7044d1570681 (commit) from c814fb2991fc9d44c7466da5bbf20e58c0f4238f (commit) Those revisions listed above that are new to this repository have not appeared on any other notification email; so we list those revisions in full, below. - Log ----------------------------------------------------------------- commit 43e31c593da10e6bf3c726236d3d794bc428bd3c Author: Vladimir Kisil <kisilv(a)maths.leeds.ac.uk> Date: Wed Apr 22 23:21:53 2015 +0200 Improve abs(arg). Make abs(arg) return -arg if arg is negative or if -arg is known to be nonnegative. commit 0f7f5c00470b6f1d10b668e3a7b34438ed005d0f Author: Vladimir Kisil <kisilv(a)maths.leeds.ac.uk> Date: Wed Apr 22 23:06:56 2015 +0200 Fix pow::info(info_flags::nonnegative). This function call was missing the case where a positive base is raised to a real power (where pow::info(info_flags::positive) correctly returned true). commit 62168ea93d23c81172ad07f9ec2f7044d1570681 Author: Vladimir Kisil <kisilv(a)maths.leeds.ac.uk> Date: Wed Apr 22 21:52:15 2015 +0200 Fix mul::info(info_flags::nonnegative). Due to an obvious Boolean inversion, this function call always returned the wrong answer. ----------------------------------------------------------------------- Summary of changes: ginac/inifcns.cpp | 3 +++ ginac/mul.cpp | 2 +- ginac/power.cpp | 3 ++- 3 files changed, 6 insertions(+), 2 deletions(-) hooks/post-receive -- GiNaC -- a C++ library for symbolic computations

1 0

Patches to fix nonnegative info flag
by Vladimir V. Kisil 22 Apr '15

22 Apr '15

Dear All, I am attaching three micro patches to fix problems with the following programme (present output is included): #include "ginac/ginac.h" int main(){ GiNaC::ex half=GiNaC::numeric(1,2), E=-pow(8, half); std::cout << "E nonneg: " << E.info(GiNaC::info_flags::nonnegative) << std::endl; // --> E nonneg: 1 std::cout << "Absolute value of E: " << abs(E) << std::endl; // --> Absolute value of E: -sqrt(8) std::cout << "Absolute value of (-E): " << abs(-E) << std::endl; // --> Absolute value of (-E): abs(sqrt(8)) return 0; } First, the present GiNaC returns mul::info(GiNaC::info_flags::nonnegative) just opposite to the correct one. This is one patch. Second, presently pow::info(GiNaC::info_flags::nonnegative) can be false even if pow::info(GiNaC::info_flags::positive) is true. this the second patch. Finally, I think that abs shall return -arg if arg is negative or (-arg) is nonnegative, this is the third patch. If all three patches are implemented, then the output of the above example is: E nonneg: 0 Absolute value of E: sqrt(8) Absolute value of (-E): sqrt(8) Best wishes, Vladimir -- Vladimir V. Kisil http://www.maths.leeds.ac.uk/~kisilv/ Book: Geometry of Mobius Transformations http://goo.gl/EaG2Vu Software: Geometry of cycles http://moebinv.sourceforge.net/

1 0

[SCM] GiNaC -- a C++ library for symbolic computations branch, master, updated. release_1-4-0-446-gc814fb2
by git＠ginac.de 14 Apr '15

14 Apr '15

This is an automated email from the git hooks/post-receive script. It was generated because a ref change was pushed to the repository containing the project "GiNaC -- a C++ library for symbolic computations". The branch, master has been updated via c814fb2991fc9d44c7466da5bbf20e58c0f4238f (commit) via 5745deb8dbcee040d1012b8260ed317eb2a32f4b (commit) from 0b985d5336debdd396f0fbeca8df850af5f569f4 (commit) Those revisions listed above that are new to this repository have not appeared on any other notification email; so we list those revisions in full, below. - Log ----------------------------------------------------------------- commit c814fb2991fc9d44c7466da5bbf20e58c0f4238f Author: Vladimir Kisil <kisilv(a)maths.leeds.ac.uk> Date: Tue Apr 14 23:14:09 2015 +0200 Make power::expand() (x*p)^c -> x^c * p^c, if p>0. This expansion seems to be helpful in many cases. commit 5745deb8dbcee040d1012b8260ed317eb2a32f4b Author: Martin Vala <mvala(a)saske.sk> Date: Tue Apr 14 22:50:31 2015 +0200 Make compile_ex() work with CMake. Infrastructure fixes to make CMake find libdl and make ginac-excompiler listen to the $CXXFLAGS environment variable. ----------------------------------------------------------------------- Summary of changes: CMakeLists.txt | 5 +++++ check/CMakeLists.txt | 2 +- check/exam_powerlaws.cpp | 32 ++++++++++++++++++++++++++++++ cmake/modules/FindLibDL.cmake | 30 +++++++++++++++++++++++++++++ config.cmake.in | 1 + doc/examples/compile1.cpp | 3 +++ doc/examples/compile2.cpp | 3 +++ doc/examples/compile3.cpp | 3 +++ doc/tutorial/ginac.texi | 8 +++++++- ginac/power.cpp | 45 +++++++++++++++++++++++++++++++++++++++++++ ginsh/CMakeLists.txt | 2 +- tools/CMakeLists.txt | 11 ++++++++++- tools/ginac-excompiler.in | 2 +- 13 files changed, 142 insertions(+), 5 deletions(-) create mode 100644 cmake/modules/FindLibDL.cmake hooks/post-receive -- GiNaC -- a C++ library for symbolic computations

1 0

compile_ex with HAVE_LIBDL with cmake build system
by Martin Vala 14 Apr '15

14 Apr '15

Dear ginac dev, i would like to use function compile_ex and it is not possible to set using cmake build system. I added some cmake configuration and all changes are in tarball http://alice.saske.sk/mvala/ginac/ginac-1.6.3.tar.bz2 Can you add this to 1.6.4? It would help me a lot. Thanks Ciao Martin

3 15