Re: atan2_sharp() -- a Motion?
(This is just a quick reply to John Pryce -- I have not yet had time
to dig deeper than I have so far. I'd really appreciate some help.)
On whether atan2_sharp() can be programmed using case() and the two
or three shifted-range atan2x() functions: I suppose I should try,
and identify the sticking point. If it's not possible, could we
still prove the FT(D)IA? And if not, is that the death knell?
> > If 0 is included in both xx and yy, I would pick the regular atan2(),
> > and return an enclosure of [-pi,+pi] -- though a case could be made
> > for returning the union of the two or three ranges mentioned above.
>
> I'm against an "atan2ToPair". At this late stage we couldn't discuss
> it properly & it looks like over-egging the cake.
That was Jürgen's idea (misattributed to John Pryce by Lee Winter).
I misspoke when I said "union" -- I meant "convex hull".
> Yes. I think this strict (but crude) version should be the main one,
> and be called atan2().
...by the standard. Actual names in an implementation are not prescribed,
they only have to be documented and mapped to the 1788 names.
Michel.
---Sent: 2014-02-20 14:28:48 UTC