关于三次B-样条曲线形状的一点注记

A Note on Distributional Shape of a Cubic B-Spline Curve

三次B 样条曲线在实际中得到广泛的运用 .孙家昶对该曲线的形状进行了研究 .关于在曲线上出现双拐点和奇点讨论不详尽 ,本文对之进行补充且进行讨论 ,对A3<0及A1+A2 +A3<0时曲线上出现拐点和奇点的条件 ,得到了一些结论 .

In the paper we probe and complement the theme on emergence of the inflection point and singular point which have not been fully studied in SUN Jia chang. At the same time we display conditions or prerequisites for the inflection point and singular point when it is available that A\-3<0 as well as A\-1+ A\-2+A\-3<0.