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- From: Marc Glisse <>
- To:
- Subject: Re: [cgal-discuss] imprecision in Core_Expr.h
- Date: Fri, 17 Aug 2012 15:54:46 +0200 (CEST)
On Thu, 26 Jul 2012, Marc Mörig wrote:
Dear CGAL maintainers,
in CORE_Expr.h there is twice the call
x.approx(53,1024);
meant to improve the internal approximation in x to double quality.
After a call x.approx(r,a) the internal approximation z is such that
|x - z| <= max{ |x|2^{-r}, 2^{-a} }
So that call wastes precision if x is in the underflow range. It should be
x.approx(53,1075);
since the smallest (positive nonzero) double is 2^{-1074}.
Thank you for the detailed report. It makes sense, I have made the suggested change for 4.2.
--
Marc Glisse
- Re: [cgal-discuss] imprecision in Core_Expr.h, Marc Glisse, 08/17/2012
- Re: Re: [cgal-discuss] imprecision in Core_Expr.h, Laurent Rineau (CGAL/GeometryFactory), 08/17/2012
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