-------- Original Message -------- Subject: Re: Strange behavior of numer_denom Date: Mon, 30 Jun 2003 20:07:58 +0200 From: Christian Bauer <Christian.Bauer@Uni-Mainz.DE> Reply-To: ginac-list@zino.physik.uni-mainz.de To: ginac-list@zino.physik.uni-mainz.de References: <3EFFEFC8.2090203@cs.unipr.it> Hi! On Mon, Jun 30, 2003 at 10:07:36AM +0200, Roberto Bagnara wrote:

There are two problems here: (1) the numerator and denominator returned are trivially not coprime;

numer_denom() and normal() have a problem with square roots that get squared in the process, which I suspect is what happens here (1264 = 16*79). Patches are welcome...

and (2) numer_denom does not behave like a mathematical function. With the same input, it produces the sequence of answers

{-1264*d,-1264} {1264*d,1264} [...]

The denominator should always be unit normal (= positive in this case). This problem should now be fixed in CVS. Bye, Christian -- / Physics is an algorithm \/ http://www.uni-mainz.de/~bauec002/ -- Prof. Roberto Bagnara Computer Science Group Department of Mathematics, University of Parma, Italy http://www.cs.unipr.it/~bagnara/ mailto:bagnara@cs.unipr.it