【摘要】 本文提出了一种决定双园弧样条节点处切向的极值原理,指出了“切线”与“切向”在决定曲线形态方面的差异。文中还给出了公切点参数与其它各参数间的一个简单关系,并对公切点的选取问题作了较系统的讨论,指出了它与保凸性的一定关系。更多还原

【Abstract】 Let the knotes Pi(i=0,1,…,n)be given in a plane,T~0、T~n be the tangent dire- ction at P_o and P_n respectively.In this paker,the authors propose a principle of extreme (α_i-β_i)~2=min and determine the other tangent directions T~i with these α_i A simple and important formula is as follows with this,the relation between the convexity and the locaticn of common tangent point is discussed in detail. A convenient algorithm is also given in this paper.更多还原