[Python-Dev] Signalling NANs
Chris Barker
chris.barker at noaa.gov
Fri Nov 9 16:17:09 EST 2018
works for me, too:
In [9]: x = cast_int2float(0x7ff8000000000001)
In [10]: hex(cast_float2int(x))
Out[10]: '0x7ff8000000000001'
In [11]: x = cast_int2float(0x7ff0000000000001)
In [12]: hex(cast_float2int(x))
Out[12]: '0x7ff0000000000001'
OS-X, conda build:
Python 3.7.0 | packaged by conda-forge | (default, Aug 27 2018, 17:24:52)
[Clang 6.1.0 (clang-602.0.53)] on darwin
I suspect it depends on the compiler's math library
But neither is raising an exception:
In [3]: x = cast_int2float(0x7ff0000000000001)
In [4]: y = cast_int2float(0x7ff8000000000001)
In [5]: 2.0 / x
Out[5]: nan
In [6]: 2.0 / y
Out[6]: nan
When should it?
-CHB
On Fri, Nov 9, 2018 at 3:46 AM, Serhiy Storchaka <storchaka at gmail.com>
wrote:
> 09.11.18 13:05, Steven D'Aprano пише:
>
>> py> x = cast_int2float(0x7ff0000000000001)
>> py> x
>> nan
>> py> hex(cast_float2int(x))
>> '0x7ff8000000000001'
>>
>
> I got '0x7ff0000000000001'.
>
>
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Christopher Barker, Ph.D.
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Chris.Barker at noaa.gov
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