[pstricks] inverse functions

[Jacques L'helgoualc'h]

Herbert Voss a écrit, mardi 30 septembre 2003, à 15:07 :
> Jacques L'helgoualc'h schrieb:
[...]
> > Unfortunately, atan value is not in [-90;+90], but in [0;180] :-/
> 
> it is in a range of [0;360], which makes some sense,
> when using the atan with nominator and denominator

Ok, so it  is rather equal to  (in degrees) 180 + arg(-x,-y),  and I can
plot the True Mathematical Atan(x) with

 \psplot{-8}{8}{x neg -1 atan 180 sub 180 div 3.1416 mul}

Thanks,
-- 
Jacques L'helgoualc'h