[RGEOS]数学基础

1.向量Vector3d

  1 using System;
  2 
  3 namespace RGeos.Geometry
  4 {
  5     /// <summary>
  6     /// 3D向量类
  7     /// </summary>
  8     public class Vector3d
  9     {
 10         public double[] vector;
 11         private const double E = 0.0000001f;
 12         /// <summary>
 13         /// 
 14         /// </summary>
 15         /// <param name="x"></param>
 16         /// <param name="y"></param>
 17         /// <param name="z"></param>
 18         /// 
 19         public Vector3d()
 20         {
 21             vector = new double[3];
 22         }
 23         public Vector3d(double x, double y, double z)
 24         {
 25             vector = new double[3] { x, y, z };
 26         }
 27         public Vector3d(Vector3d vct)
 28         {
 29             vector = new double[3];
 30             vector[0] = vct.X;
 31             vector[1] = vct.Y;
 32             vector[2] = vct.Z;
 33         }
 34         #region 属性
 35         /// <summary>
 36         /// X向量
 37         /// </summary>
 38         public double X
 39         {
 40             get { return vector[0]; }
 41             set { vector[0] = value; }
 42         }
 43         /// <summary>
 44         /// Y向量
 45         /// </summary>
 46         public double Y
 47         {
 48             get { return vector[1]; }
 49             set { vector[1] = value; }
 50         }
 51         /// <summary>
 52         /// Z向量
 53         /// </summary>
 54         public double Z
 55         {
 56             get { return vector[2]; }
 57             set { vector[2] = value; }
 58         }
 59         #endregion
 60 
 61         #region 向量操作
 62         /// <summary>
 63         /// /// <summary>
 64         /// 向量加法+
 65         /// </summary>
 66         /// <param name="lhs"></param>
 67         /// <param name="rhs"></param>
 68         /// <returns></returns>
 69         public static Vector3d operator +(Vector3d lhs, Vector3d rhs)//向量加
 70         {
 71             Vector3d result = new Vector3d(lhs);
 72             result.X += rhs.X;
 73             result.Y += rhs.Y;
 74             result.Z += rhs.Z;
 75             return result;
 76         }
 77         /// <summary>
 78         /// 向量减-
 79         /// </summary>
 80         /// <param name="lhs"></param>
 81         /// <param name="rhs"></param>
 82         /// <returns></returns>
 83         public static Vector3d operator -(Vector3d lhs, Vector3d rhs)//向量减法
 84         {
 85             Vector3d result = new Vector3d(lhs);
 86             result.X -= rhs.X;
 87             result.Y -= rhs.Y;
 88             result.Z -= rhs.Z;
 89             return result;
 90         }
 91         /// <summary>
 92         /// 向量除
 93         /// </summary>
 94         /// <param name="lhs"></param>
 95         /// <param name="rhs"></param>
 96         /// <returns></returns>
 97         public static Vector3d operator /(Vector3d lhs, double rhs)//向量除以数量
 98         {
 99             if (rhs != 0)
100                 return new Vector3d(lhs.X / rhs, lhs.Y / rhs, lhs.Z / rhs);
101             else
102                 return new Vector3d(0, 0, 0);
103         }
104         /// <summary>
105         /// 向量数乘*
106         /// </summary>
107         /// <param name="lhs"></param>
108         /// <param name="rhs"></param>
109         /// <returns></returns>
110         public static Vector3d operator *(double lhs, Vector3d rhs)//左乘数量
111         {
112             return new Vector3d(lhs * rhs.X, lhs * rhs.Y, lhs * rhs.Z);
113         }
114         /// <summary>
115         /// 向量数乘
116         /// </summary>
117         /// <param name="lhs"></param>
118         /// <param name="rhs"></param>
119         /// <returns></returns>
120         public static Vector3d operator *(Vector3d lhs, double rhs)//右乘数量
121         {
122             return new Vector3d(lhs.X * rhs, lhs.Y * rhs, lhs.Z * rhs);
123         }
124 
125         /// <summary>
126         /// 判断量向量是否相等
127         /// </summary>
128         /// <param name="lhs"></param>
129         /// <param name="rhs"></param>
130         /// <returns>True 或False</returns>
131         public static bool operator ==(Vector3d lhs, Vector3d rhs)
132         {
133             if (Math.Abs(lhs.X - rhs.X) < E && Math.Abs(lhs.Y - rhs.Y) < E && Math.Abs(lhs.Z - rhs.Z) < E)
134                 return true;
135             else
136                 return false;
137         }
138         public static bool operator !=(Vector3d lhs, Vector3d rhs)
139         {
140             return !(lhs == rhs);
141         }
142         public override bool Equals(object obj)
143         {
144             return base.Equals(obj);
145         }
146         public override int GetHashCode()
147         {
148             return base.GetHashCode();
149         }
150         public override string ToString()
151         {
152             return "(" + X + "," + Y + "," + Z + ")";
153         }
154         /// <summary>
155         /// 向量叉积,求与两向量垂直的向量
156         /// </summary>
157         public static Vector3d Cross(Vector3d v1, Vector3d v2)
158         {
159             Vector3d r = new Vector3d(0, 0, 0);
160             r.X = (v1.Y * v2.Z) - (v1.Z * v2.Y);
161             r.Y = (v1.Z * v2.X) - (v1.X * v2.Z);
162             r.Z = (v1.X * v2.Y) - (v1.Y * v2.X);
163             return r;
164         }
165         /// <summary>
166         /// 向量数量积
167         /// </summary>
168         /// <param name="lhs"></param>
169         /// <param name="rhs"></param>
170         /// <returns></returns>
171         public static double operator *(Vector3d lhs, Vector3d rhs)//
172         {
173             return lhs.X * rhs.X + lhs.Y * rhs.Y + lhs.Z * rhs.Z;
174         }
175         /// <summary>
176         /// 内积
177         /// </summary>
178         /// <param name="v1"></param>
179         /// <param name="v2"></param>
180         /// <returns></returns>
181         public static double InnerMultiply(Vector3d v1, Vector3d v2)
182         {
183             double inner = 0.0;
184             inner = v1.X * v2.X + v1.Y * v2.Y + v1.Z * v2.Z;
185             return inner;
186         }
187         /// <summary>
188         /// 求向量长度,向量的模
189         /// </summary>
190         public static double Magnitude(Vector3d v1)
191         {
192             return (double)Math.Sqrt((v1.X * v1.X) + (v1.Y * v1.Y) + (v1.Z * v1.Z));
193         }
194         /// <summary>
195         /// 单位化向量
196         /// </summary>
197         public static Vector3d Normalize(Vector3d v1)
198         {
199             double magnitude = Magnitude(v1);
200             v1 = v1 / magnitude;
201             return v1;
202         }
203         #endregion
204     }
205 }
View Code

2. 计算基础

  1 using System;
  2 using RGeos.Geometry;
  3 
  4 namespace RGeos.Basic
  5 {
  6     public class RMath
  7     {
  8         public static double SMALL_NUM = 0.0000000001; // anything that avoids division overflow
  9         /// <summary>
 10         ///  dot product (3D) which allows vector operations in arguments
 11         /// </summary>
 12         /// <param name="u"></param>
 13         /// <param name="v"></param>
 14         /// <returns></returns>
 15         public static double dot(Vector3d u, Vector3d v)
 16         {
 17             return ((u).X * (v).X + (u).Y * (v).Y + (u).Z * (v).Z);
 18         }
 19         /// <summary>
 20         /// 2D数量积,点乘
 21         /// </summary>
 22         /// <param name="u"></param>
 23         /// <param name="v"></param>
 24         /// <returns></returns>
 25         public static double dot2(Vector3d u, Vector3d v)
 26         {
 27             return ((u).X * (v).X + (u).Y * (v).Y);
 28         }
 29         /// <summary>
 30         /// 2D矢量叉积,定义为(0,0),P1,P2和P1P2包围四边形的带符号面积
 31         /// </summary>
 32         /// <param name="u"></param>
 33         /// <param name="v"></param>
 34         /// <returns></returns>
 35         public static double perp(Vector3d u, Vector3d v)
 36         {
 37             return ((u).X * (v).Y - (u).Y * (v).X);
 38         }
 39         /// <summary>
 40         /// 向量的模
 41         /// </summary>
 42         /// <param name="v"></param>
 43         /// <returns></returns>
 44         public static double norm(Vector3d v)
 45         {
 46             return Math.Sqrt(dot(v, v));  // norm = length of vector
 47         }
 48         /// <summary>
 49         /// 两点间距离
 50         /// </summary>
 51         /// <param name="u"></param>
 52         /// <param name="v"></param>
 53         /// <returns></returns>
 54         public static double d(Vector3d u, Vector3d v)
 55         {
 56             return norm(u - v);       // distance = norm of difference
 57         }
 58 
 59         public static double d(RPoint P1, RPoint P2)
 60         {
 61             return GetDistance(P1, P2);       // distance = norm of difference
 62         }
 63 
 64         // 判断点P2在直线P0P1的左边还是在右边,还是在直线上
 65         //isLeft(): tests if a point is Left|On|Right of an infinite line.
 66         //    Input:  three points P0, P1, and P2
 67         //    Return: >0 for P2 left of the line through P0 and P1
 68         //            =0 for P2 on the line
 69         //            <0 for P2 right of the line
 70         public static int isLeft(RPoint P0, RPoint P1, RPoint P2)
 71         {
 72             double l = ((P1.X - P0.X) * (P2.Y - P0.Y) - (P2.X - P0.X) * (P1.Y - P0.Y));
 73             return (int)l;
 74         }
 75         /// <summary>
 76         /// 获取由两个点所形成的向量的象限角度
 77         /// </summary>
 78         /// <param name="preCoord">第一个点的坐标</param>
 79         /// <param name="nextCoord">第二个点的坐标</param>
 80         /// <returns></returns>
 81         public static double GetQuadrantAngle(RPoint preCoord, RPoint nextCoord)
 82         {
 83             return GetQuadrantAngle(nextCoord.X - preCoord.X, nextCoord.Y - preCoord.Y);
 84         }
 85         /// <summary>
 86         /// 由增量X和增量Y所形成的向量的象限角度
 87         /// 区别方位角:方位角以正北方向顺时针
 88         /// |                    |
 89         /// |  /                 |b /
 90         /// | / a                |^/
 91         /// |/_)____象限角       |/______方位角
 92         /// </summary>
 93         /// <param name="x">增量X</param>
 94         /// <param name="y">增量Y</param>
 95         /// <returns>象限角</returns>
 96         public static double GetQuadrantAngle(double x, double y)
 97         {
 98             double theta = Math.Atan(y / x);
 99             if (x > 0 && y == 0) return 0;
100             if (x == 0 && y > 0) return Math.PI / 2;
101             if (x < 0 && y == 0) return Math.PI;
102             if (x == 0 && y < 0) return 3 * Math.PI / 2;
103 
104             if (x > 0 && y > 0) return theta;
105             if (x > 0 && y < 0) return Math.PI * 2 + theta;
106             if (x < 0 && y > 0) return theta + Math.PI;
107             if (x < 0 && y < 0) return theta + Math.PI;
108             return theta;
109         }
110         /// <summary>
111         /// 获取由相邻的三个点A-B-C所形成的两个向量之间的夹角
112         /// 向量AB,BC形成的夹角
113         /// </summary>
114         /// <param name="preCoord">第一个点</param>
115         /// <param name="midCoord">中间点</param>
116         /// <param name="nextCoord">第三个点</param>
117         /// <returns></returns>
118         public static double GetIncludedAngle(RPoint preCoord, RPoint midCoord, RPoint nextCoord)
119         {
120             double innerProduct = (midCoord.X - preCoord.X) * (nextCoord.X - midCoord.X) + (midCoord.Y - preCoord.Y) * (nextCoord.Y - midCoord.Y);
121             double mode1 = Math.Sqrt(Math.Pow((midCoord.X - preCoord.X), 2.0) + Math.Pow((midCoord.Y - preCoord.Y), 2.0));
122             double mode2 = Math.Sqrt(Math.Pow((nextCoord.X - midCoord.X), 2.0) + Math.Pow((nextCoord.Y - midCoord.Y), 2.0));
123             return Math.Acos(innerProduct / (mode1 * mode2));
124         }
125         /// <summary>
126         /// 获取由两个点所形成的向量的模(长度)
127         /// </summary>
128         /// <param name="preCoord">第一个点</param>
129         /// <param name="nextCoord">第二个点</param>
130         /// <returns>由两个点所形成的向量的模(长度)</returns>
131         public static double GetDistance(RPoint preCoord, RPoint nextCoord)
132         {
133             return Math.Sqrt(Math.Pow((nextCoord.X - preCoord.X), 2) + Math.Pow((nextCoord.Y - preCoord.Y), 2));
134         }
135     }
136 }
RMath
原文地址:https://www.cnblogs.com/yhlx125/p/3438857.html