[Numpy-discussion] Equvalent function for Ceil() and Floor()

[Chris Barker - NOAA Federal]

On Mon, May 20, 2013 at 8:54 AM, Bakhtiyor Zokhidov
<bakhtiyor_zokhidov at mail.ru> wrote:

> what about the following example:
>>>>new_ceil(-0.24, 0.25)
> -0.0

ceil rounds toward +inf (and floor towards -inf) -- this is exactly
what you want if you're doing what I think you are...(note that
round() rounds towards and away from zero -- so different for negative
numbers...)

the minus sign means "minus 0.0", which is a seemingly odd floating
point thing -- but FP numbers have a sign bit, which, in this case, is
set to negative, even though, mathematically speaking, 0.0 doesn't
have a sign. But it will compare to 0.0 as you'd expect:

In [8]: -0.0 == 0.0
Out[8]: True

In [9]: -0.0 <  0.0
Out[9]: False

-Chris

-- 

Christopher Barker, Ph.D.
Oceanographer

Emergency Response Division
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Chris.Barker at noaa.gov