atan2(x,x)



-----Raymond Toy <toy.raymond at gmail.com> wrote: -----


>How?is?atan2?defined?for?non-real?arguments?
>
>Ray

x + %i * y = sqrt(x^2 + y^2) * exp(%i * atan2(y,x)), so
atan2(y,x) = -%i*log((y+%i*x)/sqrt(y^2+x^2)). From what
I can tell, Maple and Mathematica are the same as Maxima:

 (%i1) logarc(atan2(x,y));
 (%o1) -%i*log((y+%i*x)/sqrt(y^2+x^2))

The SBCL atan function rejects non-real arguments.

Barton