2.9BSD - /usr/src/lib/m/hypot.c

   1: /*
   2:  * sqrt(a^2 + b^2)
   3:  *	(but carefully)
   4:  */
   5: 
   6: double sqrt();
   7: double
   8: hypot(a,b)
   9: double a,b;
  10: {
  11:     double t;
  12:     if(a<0) a = -a;
  13:     if(b<0) b = -b;
  14:     if(a > b) {
  15:         t = a;
  16:         a = b;
  17:         b = t;
  18:     }
  19:     if(b==0) return(0.);
  20:     a /= b;
  21:     /*
  22: 	 * pathological overflow possible
  23: 	 * in the next line.
  24: 	 */
  25:     return(b*sqrt(1. + a*a));
  26: }
  27: 
  28: struct  complex
  29: {
  30:     double  r;
  31:     double  i;
  32: };
  33: 
  34: double
  35: cabs(arg)
  36: struct complex arg;
  37: {
  38:     double hypot();
  39: 
  40:     return(hypot(arg.r, arg.i));
  41: }

Defined functions

Defined struct's