Message 57088 - Python tracker

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Author	inducer
Recipients	inducer
Date	2007-11-03.18:58:57
SpamBayes Score	0.010958483
Marked as misclassified	No
Message-id	<1194116338.25.0.15025018351.issue1381@psf.upfronthosting.co.za>
In-reply-to

Content
This here basically says it all: >>> import cmath;[cmath.asinh(i*1e-17).real for i in range(0,20)] [4.4408920985006257e-16, 4.4408920985006257e-16, 4.4408920985006257e-16, 4.4408920985006257e-16, 4.4408920985006257e-16, 4.4408920985006257e-16, 4.4408920985006257e-16, 4.4408920985006257e-16, 4.4408920985006257e-16, 4.4408920985006257e-16, 4.4408920985006257e-16, 4.4408920985006257e-16, 4.4408920985006257e-16, 4.4408920985006257e-16, 4.4408920985006257e-16, 4.4408920985006257e-16, 4.4408920985006257e-16, 4.4408920985006257e-16, 4.4408920985006257e-16, 4.4408920985006257e-16] The boost.math toolkit at [2] is an implementation that does better in the above (real-only) aspect. [2] http://freespace.virgin.net/boost.regex/toolkit/html/index.html Tim Peters remarks in [1] that basically all of cmath is unsound. http://mail.python.org/pipermail/python-bugs-list/2001-February/004126.html I just wanted to make sure that this issue remains on the radar.

This here basically says it all:

>>> import cmath;[cmath.asinh(i*1e-17).real for i in range(0,20)]
[4.4408920985006257e-16, 4.4408920985006257e-16, 4.4408920985006257e-16,
4.4408920985006257e-16, 4.4408920985006257e-16, 4.4408920985006257e-16,
4.4408920985006257e-16, 4.4408920985006257e-16, 4.4408920985006257e-16,
4.4408920985006257e-16, 4.4408920985006257e-16, 4.4408920985006257e-16,
4.4408920985006257e-16, 4.4408920985006257e-16, 4.4408920985006257e-16,
4.4408920985006257e-16, 4.4408920985006257e-16, 4.4408920985006257e-16,
4.4408920985006257e-16, 4.4408920985006257e-16]

The boost.math toolkit at [2] is an implementation that does better in
the above (real-only) aspect.
[2] http://freespace.virgin.net/boost.regex/toolkit/html/index.html

Tim Peters remarks in [1] that basically all of cmath is unsound.
http://mail.python.org/pipermail/python-bugs-list/2001-February/004126.html

I just wanted to make sure that this issue remains on the radar.

History
Date	User	Action	Args
2007-11-03 18:58:58	inducer	set	spambayes_score: 0.0109585 -> 0.010958483 recipients: + inducer
2007-11-03 18:58:58	inducer	set	spambayes_score: 0.0109585 -> 0.0109585 messageid: <1194116338.25.0.15025018351.issue1381@psf.upfronthosting.co.za>
2007-11-03 18:58:58	inducer	link	issue1381 messages
2007-11-03 18:58:57	inducer	create