cabs

Complex absolute value.

SYNOPSIS:

double cabs();
cmplx z;
double a;
a = cabs(&z);

DESCRIPTION:

If z = x + iy

then

       a = sqrt(x**2 + y**2).

Overflow and underflow are avoided by testing the magnitudes of x and y before squaring. If either is outside half of the floating point full scale range, both are rescaled.

ACCURACY:

                      Relative error:
arithmetic   domain     # trials      peak         rms
    DEC       -30,+30     30000       3.2e-17     9.2e-18
    IEEE      -10,+10    100000       2.7e-16     6.9e-17

JavaScript:

var z = {"r":3.14,"i":3.14};
var a = cephes.cabs(z);

where a is an object of schema

{
"r" : double,
"i" : double
}