Re: Inferring array index type from array object

["John B. Matthews" <nospam@nospam.invalid>]

In article <Xns9DA69DDA9F2AWarrensBlatherings@81.169.183.62>,
 Warren <ve3wwg@gmail.com> wrote:

> >> I was looking for the inverse of a complex  number function.
[...]
> > So, what is the "missing" function?
> > 
> > <http://www.adaic.com/standards/05rm/html/RM-G-1-2.html>
> 
> 1) The "inverse" of a complex number. 

Ah, the multiplicative inverse. I thought you meant inverse of a 
complex valued function, such as Exp/Log or Sin/Arcsin. As Adam 
and Damien suggested, 1.0 / Z looks right:

function "/" (Left : Real'Base; Right : Complex) return Complex;

<http://www.adaic.com/standards/05rm/html/RM-G-1-1.html>

> 2) Also, math libraries usually include atan2(y,x),
> since the error can be large with certain ranges
> of x in the tan(x) form:
> 
> #include <math.h>
> 
> double atan2(double y, double x);
> float atan2f(float y, float x);
> long double atan2l(long double y, long double x);

Adam also mentioned Arctan for real values:

<http://www.adaic.com/standards/05rm/html/RM-A-5-1.html>

For complex values, you may want "the principal value of the 
argument of the complex number x + iy."

<http://en.wikipedia.org/wiki/Inverse_trigonometric_functions>

function Argument (X : Complex) return Real'Base;

<http://www.adaic.com/standards/05rm/html/RM-G-1-1.html>

-- 
John B. Matthews
trashgod at gmail dot com
<http://sites.google.com/site/drjohnbmatthews>