On 2014-09-18 16:20, Ian Cordasco wrote:
On Thu, Sep 18, 2014 at 9:09 AM, Petr Viktorin firstname.lastname@example.org wrote:
On Thu, Sep 18, 2014 at 3:38 PM, Ian Cordasco email@example.com wrote:
On Sep 18, 2014 2:31 AM, "Petr Viktorin" firstname.lastname@example.org wrote:
For the record, this gives inf in Numpy.
> import numpy > numpy.array(float('inf')) // 1
AFAIK this and http://bugs.python.org/issue22198 are the only differences from Python floats, at least on my machine.
That's an interesting bug report and it's significantly different (mathematically speaking) from the discussion here. That aside, I have to wonder if numpy has its own way of representing infinity and how that behaves. I still maintain that it's least surprising for float('inf') // 1 to be NaN. You're trying to satisfy float('inf') = mod + 1 * y and in this case mod and y are both indeterminate (because this is basically a nonsensical equation).
Well, in `x = y // a`, as y tends towards infinity, x will also tend towards infinity, though in discrete steps. Yes, you get an indeterminate value, but one that's larger than any real number.
Sorry? If you've studied mathematics you'd know there's no discrete value that is the same as infinity.
[snip] He didn't say that infinity was a discrete value, he said that x will tend towards infinity in discrete steps.