On 9/19/06, Tim Hochberg <[EMAIL PROTECTED]> wrote:
That sounds right. Nan can't be compared because, well, it is undefined. For instance:
In [73]: a = arange(2)
In [74]: a/0
Out[74]: array([0, 0])
In [75]: a/0.0
Out[75]: array([ nan, inf])
In [76]: a/(-0.0)
Out[76]: array([ nan, -inf])
I.e., 0.0/0.0 is undefined. But unless the hardware generates the exception I would be loath to introduce checks in the code. Putting a check in the innermost loop of the sorts would cost significant time.
But look at the integer division by zero where the IEEE stuff has no relevence. That sure looks like a bug to me.
<snip>
Chuck
Keith Goodman wrote:
> In what order would you like argsort to sort the values -inf, nan, inf?
>
Ideally, -inf should sort first, inf should sort last and nan should
raise an exception if present.
-tim
That sounds right. Nan can't be compared because, well, it is undefined. For instance:
In [73]: a = arange(2)
In [74]: a/0
Out[74]: array([0, 0])
In [75]: a/0.0
Out[75]: array([ nan, inf])
In [76]: a/(-0.0)
Out[76]: array([ nan, -inf])
I.e., 0.0/0.0 is undefined. But unless the hardware generates the exception I would be loath to introduce checks in the code. Putting a check in the innermost loop of the sorts would cost significant time.
But look at the integer division by zero where the IEEE stuff has no relevence. That sure looks like a bug to me.
Chuck
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