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/*
* -- SuperLU routine (version 2.0) --
* Univ. of California Berkeley, Xerox Palo Alto Research Center,
* and Lawrence Berkeley National Lab.
* November 15, 1997
*
*/
/*
* This file defines common arithmetic operations for complex type.
*/
#include <math.h>
#include <stdio.h>
#include "scomplex.h"
/* Complex Division c = a/b */
void c_div(complex *c, complex *a, complex *b)
{
float ratio, den;
float abr, abi, cr, ci;
if( (abr = b->r) < 0.)
abr = - abr;
if( (abi = b->i) < 0.)
abi = - abi;
if( abr <= abi ) {
if (abi == 0) {
fprintf(stderr, "z_div.c: division by zero");
exit (-1);
}
ratio = b->r / b->i ;
den = b->i * (1 + ratio*ratio);
cr = (a->r*ratio + a->i) / den;
ci = (a->i*ratio - a->r) / den;
} else {
ratio = b->i / b->r ;
den = b->r * (1 + ratio*ratio);
cr = (a->r + a->i*ratio) / den;
ci = (a->i - a->r*ratio) / den;
}
c->r = cr;
c->i = ci;
}
/* Returns sqrt(z.r^2 + z.i^2) */
double c_abs(complex *z)
{
float temp;
float real = z->r;
float imag = z->i;
if (real < 0) real = -real;
if (imag < 0) imag = -imag;
if (imag > real) {
temp = real;
real = imag;
imag = temp;
}
if ((real+imag) == real) return(real);
temp = imag/real;
temp = real*sqrt(1.0 + temp*temp); /*overflow!!*/
return (temp);
}
/* Approximates the abs */
/* Returns abs(z.r) + abs(z.i) */
double c_abs1(complex *z)
{
float real = z->r;
float imag = z->i;
if (real < 0) real = -real;
if (imag < 0) imag = -imag;
return (real + imag);
}
/* Return the exponentiation */
void c_exp(complex *r, complex *z)
{
float expx;
expx = exp(z->r);
r->r = expx * cos(z->i);
r->i = expx * sin(z->i);
}
/* Return the complex conjugate */
void r_cnjg(complex *r, complex *z)
{
r->r = z->r;
r->i = -z->i;
}
/* Return the imaginary part */
double r_imag(complex *z)
{
return (z->i);
}
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