Re: Slaying the HYPOTamus

On Tue, Aug 25, 2009 at 1:14 AM, Tom Lane<tgl@sss.pgh.pa.us> wrote:
> Paul Matthews <plm@netspace.net.au> writes:
>> Just trying to implement correct C99 behaviour here.
>
> Around here we tend to read the Single Unix Spec before C99, and SUS
> saith something different:

It doesn't seem to anticipate NaN at all.

Neither of these seems on-point since we're neither implementing SuS
nor a C compiler. In fact we're not even implementing hypot().

We're implementing things like box_distance and point_distance which
as it happens will already be doing earlier arithmetic on the doubles,
so whatever HYPOT() does had better be consistent with that or the
results will be just an inexplicable mishmash.

Incidentally, what on earth does it mean to multiply or divide a
circle by a point?




-- 
greg
http://mit.edu/~gsstark/resume.pdf