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Re: Change definition of complex::norm
- To: Brad Lucier <lucier at math dot purdue dot edu>
- Subject: Re: Change definition of complex::norm
- From: Benjamin Kosnik <bkoz at redhat dot com>
- Date: Thu, 1 Nov 2001 18:17:15 -0800 (PST)
- cc: Gabriel Dos Reis <gdr at codesourcery dot com>, Brad Lucier <lucier at math dot purdue dot edu>, gcc at gcc dot gnu dot org, hjstein at bloomberg dot com, nbecker at fred dot net
We might want to consider moving this over to the libstdc++ list, instead
> Sorry, I forgot that the exponent range is not symmetric, the formula I
> gave for the absolute error tolerance is incorrect. The smallest
> nonzero denormal in double precision IEEE is 4.940656e-324. And in the
> example I gave, the answer in exact arithmetic is exactly halfway between
> 4.940656e-324 and 0.0, so there is little to choose between them.
I'm hoping Gaby will summarize this argument.
I would think that this patch could go in, or be provided for float,
double specializations of complex.
Can you generate a patch and post it to firstname.lastname@example.org?
Does this impact the performance noted here: