28 Apr
2011
28 Apr
'11
1:53 a.m.
On Thu, Apr 28, 2011 at 12:24 AM, Guido van Rossum <guido@python.org> wrote:
So do new masks get created when the outcome of an elementwise operation is a NaN? Because that's the only reason why one should have NaNs in one's data in the first place.
If this is the case, why Python almost never produces NaNs as IEEE standard prescribes?
0.0/0.0 Traceback (most recent call last): File "<stdin>", line 1, in <module> ZeroDivisionError: float division
-- not to indicate missing values!
Sometimes you don't have a choice. For example when you data comes from a database that uses NaNs for missing values.