--- On Sun, 10/17/10, Vladimir V. Kisil <kisilv@maths.leeds.ac.uk> wrote:
From: Vladimir V. Kisil <kisilv@maths.leeds.ac.uk> Subject: Re: [GiNaC-devel] About a (poor) parity in expressions. To: "GiNaC development list" <ginac-devel@ginac.de>, "Francois Maltey" <fmaltey@nerim.fr> Cc: "Vladimir V. Kisil" <kisilv@maths.leeds.ac.uk> Date: Sunday, October 17, 2010, 10:28 AM Dear Francois,
On Sun, 17 Oct 2010 16:31:20 +0200, Francois Maltey <fmaltey@nerim.fr> said: FM> After some computations, I offen get a result as sin(x)+sin(-x) FM> or cos(x)-cos(-x).
I am facing similar situations very often. If there is a predictable pattern in the answer I am employing a custom replacement (subs() method) with wildcards. This is rather effective and much safer than to put it into the core GiNaC.
So far software is not smart enough to make all possible tricks, it may be reasonable to leave the final touch to humans.
Best wishes, Vladimir -- Vladimir V. Kisil email: kisilv@maths.leeds.ac.uk -- www: http://www.maths.leeds.ac.uk/~kisilv/ _______________________________________________ GiNaC-devel mailing list GiNaC-devel@ginac.de https://www.cebix.net/mailman/listinfo/ginac-devel
To me it looks like two missing rewriting rules. Regards, Sergei.