| 摘要 |
PURPOSE:To simplify processing logic and to shorten processing time by retrieving a circular arc along a closed area, adding a code corresponding to the direction the circular arc against the direction of the retrieval to the area of the circular arc, and adding the result to the area of the area less arc-area. CONSTITUTION:As shown in the figure B, the area excluding the circular arc area from contour line data is calculated, and the areal calculation of the circular arc area is executed as follow: assuming the retrieval direction of the circular arc to be a counterclockwise direction as C-E, a positive code is added to the area of the circular arc area l2 since the circular arc l2 has the counterclockwise direction as C. Similarly, since a circular arc l5 has a clockwise direction as D, a negative sign is added to the area of the arc-area l5. Since a circular arc l8 has a counterclockwise direction, a positive code is added to the area of the circular arc area l8. By adding these results with each other, the area of the closed area including the circular arc area can be obtained. |
