13 #include "qwt_global.h" 
   77     void setSplineType( SplineType );
 
   78     SplineType splineType() 
const;
 
   80     bool setPoints( 
const QPolygonF& points );
 
   81     QPolygonF points() 
const;
 
   86     double value( 
double x ) 
const;
 
   88     const QVector<double> &coefficientsA() 
const;
 
   89     const QVector<double> &coefficientsB() 
const;
 
   90     const QVector<double> &coefficientsC() 
const;
 
   93     bool buildNaturalSpline( 
const QPolygonF & );
 
   94     bool buildPeriodicSpline( 
const QPolygonF & );