[GiNaC-list] Bug with matrix subtraction

Martin Sandve Alnæs martinal at simula.no
Thu Mar 22 11:24:03 CET 2007


2007/3/22, Sheplyakov Alexei <varg at theor.jinr.ru>:
> Hello!
>
> On Thu, Mar 22, 2007 at 09:44:03AM +0100, Martin Sandve Alnæs wrote:
>
> > If I subtract two equal matrices, I get the scalar 0.
>
> In GiNaC (A-A) is always transformed into 0 (number). I admit this is
> ugly, but fixing it would be very difficult (if possible at all).

I see.

> > If I do a+(-b) instead of a-b, I get a zero matrix as wanted.
>
> Interesting. I get zero (a number) in both ways:

Seems like the matrix with zeros only happens when using the swiginac
bindings, so techniqually the bug is there.

Thanks for the quick response, anyway.

martin


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