/// <summary>
/// 计算IGeometry的椭球面的面积
/// 虚态
/// </summary>
/// <param name="geo">要计算的IGeometry几何对象</param>
/// <returns>(IGeometry as IArea).Area</returns>
public virtual decimal Compute(IGeometry geo)
{
decimal rbc = 0.0M;
if (geo is IArea)
{
rbc = Maths.Todecimal((geo as IArea).Area);
}
return(rbc);
}
/// <summary>
/// 计算IGeometry的椭球面的 理论面积
/// </summary>
/// <param name="geo">输入的分幅图的几何对象IGeometry(矩形状)</param>
/// <returns>(单位：平方米)</returns>
public override decimal Compute(IGeometry geo)
{
decimal P = 0.0M;
//(1)最大最小角计算出WGS84大地经纬度坐标(四个点) 经差/纬差
decimal xmin = Maths.Todecimal(geo.Envelope.XMin);
decimal ymin = Maths.Todecimal(geo.Envelope.YMin);
decimal xmax = Maths.Todecimal(geo.Envelope.XMax);
decimal ymax = Maths.Todecimal(geo.Envelope.YMax);
//(2)转为经纬度坐标
decimal Bmin = 0.0M;//ToWGS84(xmin,ymin)
decimal Lmin = 0.0M;
decimal BMax = 0.0M;//ToWGS84(xmax,ymax)
decimal Lmax = 0.0M;
//double dL = Lmax - Lmin; //经差△L
//double dB = BMax - Bmin; //纬差(B2-B1)
//比例尺 5千
IMapScale scale = new MapScale_5000();
decimal dL = scale.L2_L1; //(单位：弧度)
decimal dB = scale.B2_B1; //(单位：弧度)
//default=西安椭球体参数
decimal b = this.EllipseParameter.b;
decimal a = this.EllipseParameter.a;
decimal A = this.EllipseParameter.A;
decimal B = this.EllipseParameter.B;
decimal C = this.EllipseParameter.C;
decimal D = this.EllipseParameter.D;
decimal E = this.EllipseParameter.E;
decimal Bm = (Bmin + BMax) / 2;
decimal CosBm = Maths.Cos(Bm);
decimal Cos3Bm = Maths.Cos(3 * Bm);
decimal Cos5Bm = Maths.Cos(5 * Bm);
decimal Cos7Bm = Maths.Cos(7 * Bm);
decimal Cos9Bm = Maths.Cos(9 * Bm);
P = ((4 * PI * b * b * dL) / (360 * 60)) * (A * Maths.Sin(dB * 1 / 2) * CosBm
- B * Maths.Sin(dB * 3 / 2) * Cos3Bm
+ C * Maths.Sin(dB * 5 / 2) * Cos5Bm
- D * Maths.Sin(dB * 7 / 2) * Cos7Bm
+ E * Maths.Sin(dB * 9 / 2) * Cos9Bm);
return(P); //(单位：平方米)
}
public SpatialReference_EllipseParameter(ISpatialReference sr)
{
if (sr is IGeographicCoordinateSystem)
{
IGeographicCoordinateSystem system = sr as IGeographicCoordinateSystem;
this.m_a = Maths.Todecimal(system.Datum.Spheroid.SemiMajorAxis); //长半轴
this.m_b = Maths.Todecimal(system.Datum.Spheroid.SemiMinorAxis); //短半轴
this.m_alphi = Maths.Todecimal(system.Datum.Spheroid.Flattening); //扁率
}
//计算A-E参数
this.ComputerAE_Parameter();
}
public decimal GetRingEllipse(IGeometry geo)
{
IPointCollection pointColl = geo as IPointCollection;
IPoint point = null;
decimal x = 0, y = 0;
decimal[] B = new decimal[pointColl.PointCount];
decimal[] L = new decimal[pointColl.PointCount];
for (int i = 0; i < pointColl.PointCount; i++)
{
point = pointColl.get_Point(i);
x = Maths.Todecimal(point.X); y = Maths.Todecimal(point.Y);
B[i] = y;
L[i] = x;
}
decimal sum = 0;
for (int i = 0; i < B.Length; i++)
{
if (i < B.Length - 1)
{
//double n = GetSign(L[i], L[i + 1]) * (Math.Abs(B[i] + B[i + 1]) * Math.Abs(L[i + 1] - L[i])) / 2;
decimal n = this.Compute(B[i + 1], L[i + 1], B[i], L[i]);
//System.Diagnostics.Debug.WriteLine(n.ToString());
sum += n;
}
else
{
//double r = GetSign(L[B.Length - 1], L[0]) * (Math.Abs(B[0] + B[B.Length - 1]) * Math.Abs(L[0] - L[B.Length - 1])) / 2;
decimal r = this.Compute(B[0], L[0], B[B.Length - 1], L[L.Length - 1]);
//System.Diagnostics.Debug.WriteLine(r.ToString());
sum += r;
}
}
sum = Math.Abs(sum);
return(sum);
}
public decimal GetRingEllipse(IGeometry geo)
{
IPointCollection pointColl = geo as IPointCollection;
IPoint point = null;
decimal x = 0;
decimal y = 0;
decimal[] B = new decimal[pointColl.PointCount];
decimal[] L = new decimal[pointColl.PointCount];
int intPart = 0;
if (this.Datum == EnumProjectionDatum.Xian80)
{ //西安80系
for (int i = 0; i < pointColl.PointCount; i++)
{
point = pointColl.get_Point(i);
x = Maths.Todecimal(point.X); y = Maths.Todecimal(point.Y);
intPart = (int)x;
if (intPart.ToString().Length == 6)
{ //x坐标实质是小数坐标
this.IsBigNumber = false;
}
if (intPart.ToString().Length == 8)
{ //x坐标实质是小数坐标
this.IsBigNumber = true;
}
//高斯反算
if (this.gassConv is GSCoordConVertionClass_Xian80_Call2)
{
(this.gassConv as GSCoordConVertionClass_Xian80_Call2).IsBigNumber = this.IsBigNumber;
(this.gassConv as GSCoordConVertionClass_Xian80_Call2).Strip = this.Strip;
(this.gassConv as GSCoordConVertionClass_Xian80_Call2).L0 = this.L0;
(this.gassConv as GSCoordConVertionClass_Xian80_Call2).GetBLFromXY(y, x, ref B[i], ref L[i]);
}
else
{
this.gassConv.GetBLFromXY(y, x, ref B[i], ref L[i], 1, this.Datum, this.Strip, this.L0, this.IsBigNumber);
}
}
}
else if (this.Datum == EnumProjectionDatum.CGCS2000)
{ //2000坐标系
for (int i = 0; i < pointColl.PointCount; i++)
{
point = pointColl.get_Point(i);
x = Maths.Todecimal(point.X); y = Maths.Todecimal(point.Y);
intPart = (int)x;
if (intPart.ToString().Length == 6)
{ //x坐标实质是小数坐标
this.IsBigNumber = false;
}
if (intPart.ToString().Length == 8)
{ //x坐标实质是小数坐标
this.IsBigNumber = true;
}
//高斯反算
if (this.gassConv is GSCoordConvertionClass_CGCS_2000)
{
(this.gassConv as GSCoordConvertionClass_CGCS_2000).IsBigNumber = this.IsBigNumber;
(this.gassConv as GSCoordConvertionClass_CGCS_2000).Strip = this.Strip;
(this.gassConv as GSCoordConvertionClass_CGCS_2000).L0 = this.L0;
(this.gassConv as GSCoordConvertionClass_CGCS_2000).GetBLFromXY(y, x, ref B[i], ref L[i]);
}
else
{
this.gassConv.GetBLFromXY(y, x, ref B[i], ref L[i], 1, this.Datum, this.Strip, this.L0, this.IsBigNumber);
}
}
}
else
{ //北京54
for (int i = 0; i < pointColl.PointCount; i++)
{
point = pointColl.get_Point(i);
x = Maths.Todecimal(point.X); y = Maths.Todecimal(point.Y);
//高斯反算
this.gassConv.GetBLFromXY(y, x, ref B[i], ref L[i], 1, this.Datum, this.Strip, this.L0, this.IsBigNumber);
}
}
decimal sum = 0;
for (int i = 0; i < B.Length; i++)
{
if (i < B.Length - 1)
{
//double n = GetSign(L[i], L[i + 1]) * (Math.Abs(B[i] + B[i + 1]) * Math.Abs(L[i + 1] - L[i])) / 2;
decimal n = this.Compute(B[i + 1], L[i + 1], B[i], L[i]);
//System.Diagnostics.Debug.WriteLine(n.ToString());
sum += n;
}
else
{
//double r = GetSign(L[B.Length - 1], L[0]) * (Math.Abs(B[0] + B[B.Length - 1]) * Math.Abs(L[0] - L[B.Length - 1])) / 2;
decimal r = this.Compute(B[0], L[0], B[B.Length - 1], L[L.Length - 1]);
//System.Diagnostics.Debug.WriteLine(r.ToString());
sum += r;
}
}
sum = Math.Abs(sum);
return(sum);
}
/// <summary>
/// 计算IGeometry的椭球面的 理论面积
/// </summary>
/// <param name="geo">输入的分幅图的几何对象IGeometry(矩形状)</param>
/// <returns>(单位：平方米)</returns>
public override decimal Compute(IGeometry geo)
{
decimal P = 0.0M;
decimal Lany = 60.0M;
decimal ShapeArea = 0;
//(1)最大最小角计算出WGS84大地经纬度坐标(四个点) 经差/纬差
decimal xmin = Maths.Todecimal(geo.Envelope.XMin);
decimal ymin = Maths.Todecimal(geo.Envelope.YMin);
decimal xmax = Maths.Todecimal(geo.Envelope.XMax);
decimal ymax = Maths.Todecimal(geo.Envelope.YMax);
ShapeArea = Maths.Todecimal((geo as IArea).Area);
//double blxs = (geo as IArea).Area / (geo.Envelope as IArea).Area;
//(2)转为经纬度坐标 //ToWGS84(xmax,ymax)
decimal Bmin = 0, Lmin = 0, Bmax = 0, Lmax = 0;
this.gassConv.GetBLFromXY(ymin, xmin, ref Bmin, ref Lmin, 0, this.Datum, this.Strip, this.L0, this.IsBigNumber); //ToWGS84(xmin,ymin)
this.gassConv.GetBLFromXY(ymax, xmax, ref Bmax, ref Lmax, 0, this.Datum, this.Strip, this.L0, this.IsBigNumber); //ToWGS84(xmin,ymin)
decimal dL = (Lmax + Lmin) / 2 - Lany; //经差△L
decimal dB = Bmax - Bmin; //纬差(B2-B1)
dL = dL * PI / 180; //(单位：弧度)
dB = dB * PI / 180; //(单位：弧度)
//default=西安椭球体参数
decimal b = this.EllipseParameter.b;
decimal a = this.EllipseParameter.a;
decimal A = this.EllipseParameter.A;
decimal B = this.EllipseParameter.B;
decimal C = this.EllipseParameter.C;
decimal D = this.EllipseParameter.D;
decimal E = this.EllipseParameter.E;
decimal Bm = (Bmin + Bmax) / 2;
Bm = Bm * PI / 180; //(单位：弧度)
decimal CosBm = Maths.Cos(Bm);
decimal Cos3Bm = Maths.Cos(3 * Bm);
decimal Cos5Bm = Maths.Cos(5 * Bm);
decimal Cos7Bm = Maths.Cos(7 * Bm);
decimal Cos9Bm = Maths.Cos(9 * Bm);
//求geo几何体的包络矩形的椭球面积
P = (2 * b * b * dL) * (A * Maths.Sin(dB * 1 / 2) * CosBm
- B * Maths.Sin(dB * 3 / 2) * Cos3Bm
+ C * Maths.Sin(dB * 5 / 2) * Cos5Bm
- D * Maths.Sin(dB * 7 / 2) * Cos7Bm
+ E * Maths.Sin(dB * 9 / 2) * Cos9Bm);
//正算经纬度矩形的另外两个点的投影坐标值
decimal x2 = 0, y2 = 0, x4 = 0, y4 = 0;
this.gassConv.GetXYFromBL(Bmin, Lmax, ref y2, ref x2, 0, this.Datum, EnumStrip.Strip3, this.IsBigNumber);
this.gassConv.GetXYFromBL(Bmax, Lmin, ref y4, ref x4, 0, this.Datum, EnumStrip.Strip3, this.IsBigNumber);
//求经纬度矩形的投影梯形面积(上底+下底)*高/2
decimal BLTrapeziaArea = ((x2 - xmin) + (xmax - x4)) * (ymax - ymin) / 2;
decimal LLmj = P * ShapeArea / BLTrapeziaArea;
return(LLmj); //(单位：平方米)
}