[GiNaC-devel] [SCM] GiNaC -- a C++ library for symbolic computations branch, master, updated. release_1-4-0-659-gfa1ffcfd

[Alexey Sheplyakov]

Hello,

17.06.2020, 21:54, "Richard B. Kreckel via GiNaC-devel" <ginac-devel at ginac.de>:
> 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 fa1ffcfdc9da97a6fb7cc2c9c36fe1fc45c808a9 (commit)
>       from 63453e8120d2e2eb9f1b836fc1b5651c2494ef1f (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 fa1ffcfdc9da97a6fb7cc2c9c36fe1fc45c808a9
> Author: Pierangelo Masarati <pierangelo.masarati at polimi.it>
> Date: Wed Jun 17 19:52:49 2020 +0200
>
>     Improve diff(abs(x)) for real x.

I think this patch is wrong and should be reverted.
diff(abs(x)) does not exist at x -> 0.
Alternatively one can modify the definition of numeric::step() function [1]
so it throws an exception when being evaluated at 0.

[1] https://www.ginac.de/ginac.git/?p=ginac.git;a=blob;f=ginac/numeric.cpp;hb=HEAD#l1070

There's no way to "patch" math.

Best regards,
      Alexey