#include "complex.h" #include "const.h" double abs(complex z) { register double temp; register double r = z.re; register double i = z.im; if (r < 0) r = -r; if (i == 0) return r; if (i < 0) i = -i; if (r == 0) return i; if (i > r) { temp = r; r = i; i = temp; } temp = i/r; temp = r*sqrt(1.0 + temp*temp); /*overflow!!*/ return temp; } double norm(complex z) { register double r = z.re; register double i = z.im; #define SAFE 6.521908912666391000e+18 /* 0.5*sqrt(GREATEST)*/ if (r<SAFE && i<SAFE) return r*r+i*i; return GREATEST; }