[Numpy-discussion] making the distinction between -0.0 and 0.0..

Christopher Barker Chris.Barker@noaa....
Tue Sep 29 17:48:59 CDT 2009


>> I'm assuming it's a bug that was fixed somewhere in between?

It works on my 2.5, on a PPC:

In [10]: struct.pack('>d', -0.0)
Out[10]: '\x80\x00\x00\x00\x00\x00\x00\x00'

In [11]: struct.pack('<d', -0.0)
Out[11]: '\x00\x00\x00\x00\x00\x00\x00\x80'

But not on 2.3.5 on the same PPC (big endian, yes?)

Python 2.3.5 (#1, Jan 12 2009, 14:43:55)
[GCC 3.3 20030304 (Apple Computer, Inc. build 1819)] on darwin

 >>> struct.pack('>d', -0.0)
'\x00\x00\x00\x00\x00\x00\x00\x00'
 >>> struct.pack('<d', -0.0)
'\x00\x00\x00\x00\x00\x00\x00\x00'

I wonder if this is a gcc difference, rather than a python one? 2.3.5 
was compiled with gcc3.3, and 2.5 with gcc 4.0.1.

I suppose I could test on Windows if I cared..

-Chris


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