Message 134203 - Python tracker

Message134203

Author	mark.dickinson
Recipients	jcea, mark.dickinson, rhettinger, vstinner
Date	2011-04-21.09:16:30
SpamBayes Score	4.024073e-09
Marked as misclassified	No
Message-id	<1303377391.11.0.971336768502.issue11888@psf.upfronthosting.co.za>
In-reply-to

Content
> it may be worth looking at what numpy does here. ... or it may not. NumPy just uses (approximation to 1/log(2)) * log(x) when log2 doesn't already exist. And indeed, on Windows: Python 2.7.1 \|EPD 7.0-2 (64-bit)\| (r271:86832, Dec 2 2010, 10:23:25) [MSC v.1500 64 bit (AMD64)] on win32 Type "help", "copyright", "credits" or "license" for more information. >>> import numpy >>> numpy.log2(8.0) 2.9999999999999996 I think we should be able to do better than this. :-)

Content

> it may be worth looking at what numpy does here.

... or it may not.  NumPy just uses (approximation to 1/log(2)) * log(x) when log2 doesn't already exist.  And indeed, on Windows:

Python 2.7.1 |EPD 7.0-2 (64-bit)| (r271:86832, Dec  2 2010, 10:23:25) [MSC v.1500 64 bit (AMD64)] on win32
Type "help", "copyright", "credits" or "license" for more information.
>>> import numpy
>>> numpy.log2(8.0)
2.9999999999999996

I think we should be able to do better than this. :-)

History
Date	User	Action	Args
2011-04-21 09:16:31	mark.dickinson	set	recipients: + mark.dickinson, rhettinger, jcea, vstinner
2011-04-21 09:16:31	mark.dickinson	set	messageid: <1303377391.11.0.971336768502.issue11888@psf.upfronthosting.co.za>
2011-04-21 09:16:30	mark.dickinson	link	issue11888 messages
2011-04-21 09:16:30	mark.dickinson	create