Signed zeros: is this a bug?
Terry Reedy
tjreedy at udel.edu
Sun Mar 11 12:13:36 EDT 2007
"Dan Bishop" <danb_83 at yahoo.com> wrote in message
news:1173629090.993914.55570 at 30g2000cwc.googlegroups.com...
| On Mar 11, 9:31 am, "Mark Dickinson" <dicki... at gmail.com> wrote:
| > I get the following behaviour on Python 2.5 (OS X 10.4.8 on PowerPC,
| > in case it's relevant.)
| >
| > >>> x, y = 0.0, -0.0
| > >>> x, y
| > (0.0, 0.0)
| > >>> x, y = -0.0, 0.0
| > >>> x, y
| >
| > (-0.0, -0.0)
|| IIRC, float.__repr__ just does whatever libc does. Have you tried
| using printf("%g, %g", 0.0, -0.0) in a C program?
Detailed FP behavior like this is system (and yes, libc) dependent. On
WinXP
IDLE 1.1.3
>>> x,y = 0.0, -0.0
>>> x,y
(0.0, 0.0)
>>> x,y = -0.0, 0.0
>>> x,y
(0.0, 0.0)
>>> -0.0
0.0
Terry Jan Reedy
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