德布尔算法计算B样条曲线的导矢.DOC

/德布尔算法计算 B 样条曲线的导矢double d2(int l,int j,int k,double su,double d,double u)if(l -eps) return 0.0;return (k+1-l)*(d2(l-1,j,k,su,d,u)-d2(l-1,j-1,k,su,d,u)/z;double GetDerValue(int k,double su,double d,int n,int r,double u)int i,j;double s=0.0;for(i=1;i ki-;for(j=i-k+r;j eps|s2 -eps) return s1/s2;else return 0.0;