COMPLEX - Functions to manipulate complex numbers

cadd	add two complex numbers
csub	subtract two complex numbers
cmul	multiply two complex numbers
cdiv	divide two complex numbers
cmplx	make a complex number from two real numbers
conjg	complex conjugate of a complex number 
cneg	negate a complex number
cinv	invert a complex number
csqrt	complex square root of a complex number
cexp	complex exponential of a complex number
crmul	multiply a complex number by a real number 
rcabs	real magnitude of a complex number

Structure:
typedef struct _complexStruct {  complex number
	float r,i;
} complex;

Function Prototypes:
complex cadd (complex a, complex b);
complex csub (complex a, complex b);
complex cmul (complex a, complex b);
complex cdiv (complex a, complex b);
float rcabs (complex z);
complex cmplx (float re, float im);
complex conjg (complex z);
complex cneg (complex z);
complex cinv (complex z);
complex csqrt (complex z);
complex cexp (complex z);
complex crmul (complex a, float x);

Notes:
The function "rcabs" was originally called "fcabs". This produced
a collision on some systems so a new name was chosen.

Reference:
Adapted from Press et al, 1988, Numerical Recipes in C (Appendix E).

Author:  Dave Hale, Colorado School of Mines, 06/02/89
Modified:  Dave Hale, Colorado School of Mines, 04/26/90
	Added function cinv().