atan2

[jte]

(04-11-2015 03:39 AM)Helge Gabert Wrote:  Don't forget there is also ARG

ARG(x+i*y)=ATAN2(y,x),

and ARG is built-in.

I've just tried ARG for a handful of values and have noticed a few minor details that might be worth keeping in mind.

• Both home ARG and CAS arg respect the angle measure setting (radians / degrees).
• Home ARG returns an error for zero while the CAS arg returns 0.0.
• The CAS arg deals with large and small magnitude arguments in a different manner than home ARG does. (With CAS epsilon as 1E-12 and degrees angle measure, CAS arg returns undef for 1E309+i and for 1E-12*i, 90.0 for 1e-12+1e-11*i, and 84.2894068625 for 1.01e-12+1.01e-11*i.)