Re: Arctan: to use with single or with double arguments?

[Jack Mitchell <jack@home9999.plus.com>]

Am I missing something - surely :-

        z = Force * SIN(ATAN2(x,y))

Is the same as :-

        z = Force * x / sqrt( x^2 + y^2 )

This should be much faster (and probably more accurate)
Perhaps I have got x & y swapped but you see my point.



In message
<dddf2cc2-640c-4878-8ce9-bf9ba13b3736@f6g2000yqa.googlegroups.com>, Ada
novice <ycalleecharan@gmx.com> writes
>On Sep 26, 9:31�am, Jeffrey Carter
><spam.jrcarter....@spam.not.acm.org> wrote:
>> I presume because there are some cases where one has a single-valued tangent
>> that my be used in Arctan (Tangent), but not X and Y values for Arctan
>>(Y, X).
>>
>> --
>> Jeff Carter
>> "We'll make Rock Ridge think it's a chicken
>> that got caught in a tractor's nuts!"
>> Blazing Saddles
>> 87
>
>Yes I guess so. Even simple things can easily create confusion. The
>Arctan and Arctan2 functions
>are well-explained in Norman Cohen's Ada book on page 90.
>

-- 
Jack Mitchell