#define ON  1
#define OFF 0

void spline(float x[],float y[],int n,float yp1,float ypn,float y2[],float u[]);
void splint(float xa[],float ya[],float y2a[],int n,float x,float *y);
int dsplint(float xa[],float ya[],float y2a[],int n,float x,float *y,
		float *dist,float dely);

extern float UScale;		/* spline flexibility -- 0=linear 1=cubic spline */
extern int IsoV;			/* limits violations to limits of isopleths if ON */
extern int Extrapolate; /* if OFF sets Y to end point value */
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