| 摘要 |
PURPOSE:To execute the circular graphic display with high speed and high accuracy by making the number of angles of a polygon into 2<n> with two integers (n) or above as a square number, changing successively the value of (n) until an approximate error goes to be a prescribed reference value or below to the desired radius and selecting a necessary (n) value. CONSTITUTION:When the optional peak and adjacent peak of an approximate 2<n> square inscribed to a circle O are assumed as An, B a point with the largest error to the inner circumference on the approximate 2<n> square is the middle point Mn of one side BAn corresponding to a chord, and when the intersection of a straight line OMn and the circle O is assigned as Cn, an MnCn goes to be a maximum approximate error, and by making an approximate error MnCn into a prescribed value or below, the optimization of (n) to a radius (r) is executed. An intersection Cn is inscribed to the circle O, is a peak An+1 of a 2<n+1> square including B and An into one peak and MnCn (or MnAn+1) can be easily calculated. This is successively repeated, and the 2<n> square is drawn by the (n) when a maximum approximate error MnCn comes to be a reference value epsilonor below, and then, an actual circular graphic and an approximate circle without generating the error of one dot or above can be drawn. |
