Re: Complex square root of -1 : zsqrt(-1)

Hi,
Here is another definition for |z|.
It is based on the formula : z = |z| * exp(i*arg(z)).
One can get: |z| = z * exp(-i*arg(z)).
Here is the code:
: zarg ( z: a+bi -- ) ( f: -- theta)
    fswap fatan2
;
: |z| ( z: a+bi -- ) ( f: -- |z|)
    zdup zarg 0e 0e -1e z* ( z: -i*arg[z])
    zexp z*  ( z: z*exp(-i*arg[z])
    fdrop    ( z: --) ( f: |z|)
;
But it is slower than the defintion using pythag( about 3-6 times
(tested gforth)).
Ahmed