#include "f2c.h"

#ifdef KR_headers
double d_sign(a, b) doublereal *a, *b;
#else
double d_sign(doublereal *a, doublereal *b)
#endif
{
  double x;
  x = (*a >= 0 ? *a : - *a);
  return(*b >= 0 ? x : -x);
}
