| 摘要 |
PURPOSE:To sample a feature point such as an inflection point of high performance by smoothing all curvature function by using an average of angles formed by plural segments for mutually connecting points before and after and in the vicinity of notice points and an optional reference straight line. CONSTITUTION:The angle formed by the segment Lj connecting the points before and after and in the vicinity of the notice point Pi and the reference straight line is obtained and this angle is considered to be psij. As the reference straight line, the straight line in parallel to a quadrature axis on the two-dimensional plane is considered to be the reference straight line and the plural segments Lj are selected, psij is obtained respectively thereon and the average thereof is considered to be PHIi, and then, the PHIi corresponds to the angle formed by a tangent line and the reference straight line. Accordingly, the difference DELTATHETA(DELTATHETA=PHIi-PHIi-1) between the angles PHIi, PHIi-1 of the notice point Pi and an immediately preceding point Pi-1 is the difference in a tangential direction. This DELTATHETAi from a start point to the notice point Pi and an added value thereof is considered to be all curvature value in the Pi, thereby the smoothed all curvature function can be obtained. Thereby, the sampling of the inflection point can be performed with the high performance. |
