circle

代码说明：

  演示椭圆的曲率圆的动画。该程序演示了椭圆各点的曲率变化及相应的曲率圆圆心的轨迹。(Demonstration of the curvature ellipse circle animation. The program demonstrates the various points of the curvature of the ellipse and the corresponding changes in the curvature of the round locus of the center.)