#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);

}