[Prime] Missing trigonometric/hyperbolic functions, possible navigational enhancement

[StephenG1CMZ]

(10-31-2015 08:37 PM)Han Wrote:  If you are going to eventually take the sine (or cosine, or any trig. function) of the value, then
\[ \sin(362^\circ) = \sin(2^\circ) \]
so why should it matter? I must not be understanding your post correctly...

Han, it is far more likely that it is me not explaining it well. If it is indeed a case of sin 362=sin 2 that I was trying to remember, all I can suggest is perhaps some sin algorithms lose precision or calculate for a longer time when given sin 1e30, rather than reducing the range first. Either that, or they are re-using an algorithm designed for looking up numbers from log tables
Whatever the reason and details, several astronomical algorithms do specify a range reduction - Unfortunately, most of my astronomical code is locked away inside an Amiga 1200 computer for which I no longer have a power supply, so I can't refresh my memory right now.