[Numpy-discussion] Division by zero doesn't raise exception in the integer case.

Christopher Barker Chris.Barker at noaa.gov
Wed Sep 20 17:17:58 CDT 2006

Travis Oliphant wrote:
>> In [77]: arange(5, dtype=int)/0
>> Out[77]: array([0, 0, 0, 0, 0])

> It is deliberate.   Numarray introduced it (the only difference being 
> that by default NumPy has division-by-zero erros turned off). It's tied 
> to the way floating-point division-by zero is handled.   There is a 
> valid argument for having a separate integer-division flag so that you 
> can raise exceptions for integer-division but not for floating-point 
> division.  I'm open to that change for 1.0rc1

+1  (+inf)

There is a BIG difference between getting an inf with a floating point 
computation and getting a 0 with an integer one!

Also, the default integer-division flag should be set to raise an exception.

It sure would be nice to have special values for integers too....

Travis Oliphant wrote:
> Simulating and "integer-division-by-zero"
> hardware flag is not trivial as we would have to manage context 
> switching ourselves.   So, at least for 1.0, integer and floating-point 
> division by zero are going to be handled the same.

Darn. Oh well.


Christopher Barker, Ph.D.
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Chris.Barker at noaa.gov

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