| 摘要 |
PURPOSE: To easily draw a circle which passes through plural points by storing graphic data and storing the coordinates of input points, finding the circle having two or three inputted points on the same circumference, and registering information on the found circle in a data base and displaying the found circle. CONSTITUTION: The input or cancellation of coordinates is decided (step 1) and when new coordinates are inputted, the number of the coordinates which are currently inputted is decided; when the number of coordinates is 0, 1, or 2, the input coordinates are stored, one is added to the number of input coordinates, and a mark X is displayed on a CRT (step 2-step 6). When the number of coordinates becomes 3, the linear equation of the vertical bisectors of the segments connecting the 1st point and 2nd point, and 2nd point and 3rd point is found, an intersection is found from the two vertical bisectors and stored as the center C of a circle, and the distance between the 1st point and center point C is found and stored as the radius (r) of the circle (step 7-step 10). |
