项目中用到三边定位,c#中没有MATLAB solve函数来解方程,只好人工去解方程了。
- class Program
- {
- static void Main(string[] args)
- {
- Point p1 = new Point() { X = 0, Y = 2, Distance = Math.Sqrt(5) };
- Point p2 = new Point() { X = 2, Y = 2, Distance = Math.Sqrt(5) };
- Point p3 = new Point() { X = 1, Y = 0, Distance = Math.Sqrt(0) };
- var p= GetPiontByThree(p1, p2, p3);
- Console.WriteLine("Point x:{0}",p.X);
- Console.WriteLine("Point y:{0}", p.Y);
- Console.ReadKey();
- }
- /// <summary>
- /// 三点绝对定位
- /// </summary>
- private static Point GetPiontByThree(Point p1, Point p2, Point p3)
- {
- /* Math.Pow(y1-Y)+Math.Pow(X-x1)=Math.Pow(D1)
- * Math.Pow(y2-Y)+Math.Pow(X-x2)=Math.Pow(D2)
- * Math.Pow(y3-Y)+Math.Pow(X-x3)=Math.Pow(D3)
- * 1-3.2-3解得:
- * 2 * (p1.X - p3.X)x + 2 * (p1.Y - p3.Y)y = Math.Pow(p1.X, 2) - Math.Pow(p3.X, 2) + Math.Pow(p1.Y, 2) - Math.Pow(p3.Y, 2) + Math.Pow(p3.Distance, 2) - Math.Pow(p1.Distance, 2);
- * 2 * (p2.X - p3.X)x + 2 * (p2.Y - p3.Y)y = Math.Pow(p2.X, 2) - Math.Pow(p3.X, 2) + Math.Pow(p2.Y, 2) - Math.Pow(p3.Y, 2) + Math.Pow(p3.Distance, 2) - Math.Pow(p2.Distance, 2);
- * 简化:
- * 2Ax+2By=C
- * 2Dx+2Ey=F
- * 简化:
- * x=(BF-EC)/(2BD-2AE)
- * y=(AF-DC)/(2AE-2BD)
- */
- var A = p1.X - p3.X;
- var B = p1.Y - p3.Y;
- var C = Math.Pow(p1.X, 2) - Math.Pow(p3.X, 2) + Math.Pow(p1.Y, 2) - Math.Pow(p3.Y, 2) + Math.Pow(p3.Distance, 2) - Math.Pow(p1.Distance, 2);
- var D = p2.X - p3.X;
- var E = p2.Y - p3.Y;
- var F = Math.Pow(p2.X, 2) - Math.Pow(p3.X, 2) + Math.Pow(p2.Y, 2) - Math.Pow(p3.Y, 2) + Math.Pow(p3.Distance, 2) - Math.Pow(p2.Distance, 2);
- var x = (B * F - E * C) / (2 * B * D - 2 * A * E);
- var y = (A * F - D * C) / (2 * A * E - 2 * B * D);
- Point P = new Point() { X = x, Y = y, Distance = 0 };
- return P;
- }
- }
- public class Point
- {
- public double X { get; set; }
- public double Y { get; set; }
- //表示指定点,据此点的距离
- public double Distance { get; set; }
- }