cabs.c

gcc-2.95.3 Linux下最常用的C编译器

#ifdef KR_headers
extern double sqrt();
double f__cabs(real, imag) double real, imag;
#else
#undef abs
#include <math.h>
double f__cabs(double real, double imag)
#endif
{
double temp;

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);
}