| 摘要 |
<p>PURPOSE:To eliminate a need of complicated work to suppress the occurrence of error by providing a close loop extracting means which indicates one edge at the time of arrival at a branch point to continue tracing and extracts the edge group returned to the initial edge as a close loop. CONSTITUTION:One edge on a close loop extracted by a close loop extracting part 141 is indicated to an operator as the initial edge. Two continuous edges are taken out from both ends of the initial edge with the middle point or the center of the initial edge as the start point, and one continuous edge is taken out from each of these two edges, and the middle point of a straight line connecting their end points is defined as a relay point, and this operation is repeated; and at the time of arrival at the last edge, the middle point or the center of the last edge is defined as the end point, and the start point, relay points, and the end point are connected by edges adapted to the form of the close loop to form a groove center form. A groove center form extracting means 144 is provided to execute these operations. Thus, complicated work like drawing information read, coordinate calculation, or numerical value input is unnecessary, and error is difficult to occur.</p> |
