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March 2021

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2 discussions

Improving normalisation with negative exponents
by Vladimir V. Kisil 30 Mar '21

30 Mar '21

Dear All, With version 1.8.0 of GiNaC the following code realsymbol x("x"); ex e = (exp(2*t)-exp(-2*t))/(exp(t)-exp(-t)); cout << e.normal() << endl; will through an exception terminate called after throwing an instance of 'std::logic_error' what(): heur_gcd: not an integer polynomial [1] The reason is that internally e will be converted to something like (symbol457^2-symbol457^(-2))/(symbol457 - 1/symbol457) with non-polynomial numerator and denominator. I am attaching a patch which will fix this issue. Some additional tests are included as well. Best wishes, Vladimir -- Vladimir V. Kisil http://www.maths.leeds.ac.uk/~kisilv/ Book: Geometry of Mobius Maps https://doi.org/10.1142/p835 Soft: Geometry of cycles http://moebinv.sourceforge.net/ Jupyter notebooks: https://github.com/vvkisil/MoebInv-notebooks

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[SCM] GiNaC -- a C++ library for symbolic computations branch, master, updated. release_1-4-0-711-gbe112029
by Stefan Weinzierl 24 Mar '21

24 Mar '21

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 be11202909f8014b213065ca85272af403a530f1 (commit) from ab00a3f70e343eaf5ed242e20bd01da75849bc78 (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 be11202909f8014b213065ca85272af403a530f1 Author: Stefan Weinzierl <weinzierl(a)uni-mainz.de> Date: Wed Mar 24 09:43:26 2021 +0100 G_do_hoelder: fix bug related to comparing a float with a rational number in CLN. This bug has been reported by Simone Zoia. ----------------------------------------------------------------------- Summary of changes: ginac/inifcns_nstdsums.cpp | 30 +++++++++++++++++------------- 1 file changed, 17 insertions(+), 13 deletions(-) hooks/post-receive -- GiNaC -- a C++ library for symbolic computations

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