Message 61423 - Python tracker

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Author	christian.heimes
Recipients	Rhamphoryncus, christian.heimes, gmcastil, gvanrossum, mark.dickinson, tim.peters
Date	2008-01-21.17:24:19
SpamBayes Score	0.073250964
Marked as misclassified	No
Message-id	<4794D541.7020109@cheimes.de>
In-reply-to	<1200935690.04.0.874915526538.issue1640@psf.upfronthosting.co.za>

Content
Mark Dickinson wrote: > Sorry: I should have read more carefully. So math.atanh works on Linux > but is producing some strange results on Windows. > > It's still rather puzzling though. I still suspect that it's the > argument to log1p that's coming out wrong rather than the result. It uses t = 0.5 * log1p((x + x) / (1.0 - x)) for t > 0.5. I presume the culprit is in "2 / x" where x is almost 0. Do you have an idea how we can increase the accuracy for values nearly 1.? Christian

Mark Dickinson wrote:
> Sorry:  I should have read more carefully.  So math.atanh works on Linux 
> but is producing some strange results on Windows.
> 
> It's still rather puzzling though.  I still suspect that it's the 
> argument to log1p that's coming out wrong rather than the result.

It uses t = 0.5 * log1p((x + x) / (1.0 - x)) for t > 0.5. I presume the
culprit is in "2 / x" where x is almost 0. Do you have an idea how we
can increase the accuracy for values nearly 1.?

Christian

History
Date	User	Action	Args
2008-01-21 17:24:20	christian.heimes	set	spambayes_score: 0.073251 -> 0.073250964 recipients: + christian.heimes, gvanrossum, tim.peters, mark.dickinson, Rhamphoryncus, gmcastil
2008-01-21 17:24:19	christian.heimes	link	issue1640 messages
2008-01-21 17:24:19	christian.heimes	create