| 摘要 |
<p>PURPOSE:To allow an operator to erase properly some part of a plotted picture irrespective of the area to be erased to which a graphic specifies, by deciding an appropriate rectangular erasure area from the graphic specifying the erasure area. CONSTITUTION:While data is fetched to a control part 27 from the digitizer 26 of a system, the image of an erasing curve is outputted on a screen image buffer 28, and simultaneously the extremal value of the Y axis of the erasure curve is obtained. While data is fetched to the control part 27, the image of the erasure curve is outputted on the buffer 28, and the extremal value of the Y axis is obtained when the input of the erasure curve is terminated. In both cases the obtained extremal values are divided into two series of maximum and minimum values, and a regression straight line is obtained according to the maximum and minimum values of each series. Moreover a rectangular area enclosed by straight lines passing through maximum and minimum values with respect to an X axis is obtained. Then a line picture in said area is displayed on a CRT monitor 9 and some part of the drawn picture is properly erased.</p> |
