.NET wrapper for GeographicLib::CassiniSoldner. More...

#include <CassiniSoldner.h>

Public Member Functions
	CassiniSoldner (double lat0, double lon0)

	CassiniSoldner (double lat0, double lon0, Geodesic^earth)

void	Forward (double lat, double lon, [System::Runtime::InteropServices::Out] double%x, [System::Runtime::InteropServices::Out] double%y, [System::Runtime::InteropServices::Out] double%azi, [System::Runtime::InteropServices::Out] double%rk)

void	Forward (double lat, double lon, [System::Runtime::InteropServices::Out] double%x, [System::Runtime::InteropServices::Out] double%y)

void	Reset (double lat0, double lon0)

void	Reverse (double x, double y, [System::Runtime::InteropServices::Out] double%lat, [System::Runtime::InteropServices::Out] double%lon, [System::Runtime::InteropServices::Out] double%azi, [System::Runtime::InteropServices::Out] double%rk)

void	Reverse (double x, double y, [System::Runtime::InteropServices::Out] double%lat, [System::Runtime::InteropServices::Out] double%lon)

	~CassiniSoldner ()

Public Attributes
Inspector functions
property double	LatitudeOrigin { double get()

property double	LongitudeOrigin { double get()

property double	MajorRadius { double get()

property double	Flattening { double get()

Private Member Functions
	!CassiniSoldner ()

Private Attributes
GeographicLib::CassiniSoldner *	m_pCassiniSoldner

Detailed Description

.NET wrapper for GeographicLib::CassiniSoldner.

This class allows .NET applications to access GeographicLib::CassiniSoldner.

Cassini-Soldner projection centered at an arbitrary position, lat0, lon0, on the ellipsoid. This projection is a transverse cylindrical equidistant projection. The projection from (lat, lon) to easting and northing (x, y) is defined by geodesics as follows. Go north along a geodesic a distance y from the central point; then turn clockwise 90° and go a distance x along a geodesic. (Although the initial heading is north, this changes to south if the pole is crossed.) This procedure uniquely defines the reverse projection. The forward projection is constructed as follows. Find the point (lat1, lon1) on the meridian closest to (lat, lon). Here we consider the full meridian so that lon1 may be either lon0 or lon0 + 180°. x is the geodesic distance from (lat1, lon1) to (lat, lon), appropriately signed according to which side of the central meridian (lat, lon) lies. y is the shortest distance along the meridian from (lat0, lon0) to (lat1, lon1), again, appropriately signed according to the initial heading. [Note that, in the case of prolate ellipsoids, the shortest meridional path from (lat0, lon0) to (lat1, lon1) may not be the shortest path.] This procedure uniquely defines the forward projection except for a small class of points for which there may be two equally short routes for either leg of the path.

Because of the properties of geodesics, the (x, y) grid is orthogonal. The scale in the easting direction is unity. The scale, k, in the northing direction is unity on the central meridian and increases away from the central meridian. The projection routines return azi, the true bearing of the easting direction, and rk = 1/k, the reciprocal of the scale in the northing direction.

The conversions all take place using a Geodesic object (by default Geodesic::WGS84). For more information on geodesics see geodesic. The determination of (lat1, lon1) in the forward projection is by solving the inverse geodesic problem for (lat, lon) and its twin obtained by reflection in the meridional plane. The scale is found by determining where two neighboring geodesics intersecting the central meridian at lat1 and lat1 + dlat1 intersect and taking the ratio of the reduced lengths for the two geodesics between that point and, respectively, (lat1, lon1) and (lat, lon).

C# Example:

using System;
using NETGeographicLib;
namespace example_CassiniSoldner
{
    class Program
    {
        static void Main(string[] args)
        {
            try {
                Geodesic geod = new Geodesic(); // WGS84
                const double lat0 = 48 + 50/60.0, lon0 = 2 + 20/60.0; // Paris
                CassiniSoldner proj = new CassiniSoldner(lat0, lon0, geod);
                {
                    // Sample forward calculation
                    double lat = 50.9, lon = 1.8; // Calais
                    double x, y;
                    proj.Forward(lat, lon, out x, out y);
                    Console.WriteLine(String.Format("X: {0} Y: {1}", x, y));
                }
                {
                    // Sample reverse calculation
                    double x = -38e3, y = 230e3;
                    double lat, lon;
                    proj.Reverse(x, y, out lat, out lon);
                    Console.WriteLine(String.Format("Latitude: {0} Longitude: {1}", lat, lon));
                }
            }
            catch (GeographicErr e) {
                Console.WriteLine( String.Format( "Caught exception: {0}", e.Message ) );
            }
        }
    }
}

Managed C++ Example:

// Example of using the GeographicLib::CassiniSoldner class
#include <iostream>
#include <exception>
#include <GeographicLib/Geodesic.hpp>
#include <GeographicLib/CassiniSoldner.hpp>
using namespace std;
using namespace GeographicLib;
int main() {
  try {
    Geodesic geod(Constants::WGS84_a(), Constants::WGS84_f());
    // Alternatively: const Geodesic& geod = Geodesic::WGS84();
    const double lat0 = 48 + 50/60.0, lon0 = 2 + 20/60.0; // Paris
    CassiniSoldner proj(lat0, lon0, geod);
    {
      // Sample forward calculation
      double lat = 50.9, lon = 1.8; // Calais
      double x, y;
      proj.Forward(lat, lon, x, y);
      cout << x << " " << y << "\n";
    }
    {
      // Sample reverse calculation
      double x = -38e3, y = 230e3;
      double lat, lon;
      proj.Reverse(x, y, lat, lon);
      cout << lat << " " << lon << "\n";
    }
  }
  catch (const exception& e) {
    cerr << "Caught exception: " << e.what() << "\n";
    return 1;
  }
}

Visual Basic Example:

Imports NETGeographicLib
Module example_CassiniSoldner
    Sub Main()
        Try
            Dim geod As Geodesic = New Geodesic() ' WGS84
            Dim lat0 As Double = 48 + 50 / 60.0, lon0 = 2 + 20 / 60.0 ' Paris
            Dim proj As CassiniSoldner = New CassiniSoldner(lat0, lon0, geod)
            ' Sample forward calculation
            Dim lat As Double = 50.9, lon = 1.8 ' Calais
            Dim x, y As Double
            proj.Forward(lat, lon, x, y)
            Console.WriteLine(String.Format("X: {0} Y: {1}", x, y))
            ' Sample reverse calculation
            x = -38000.0 : y = 230000.0
            proj.Reverse(x, y, lat, lon)
            Console.WriteLine(String.Format("Latitude: {0} Longitude: {1}", lat, lon))
        Catch ex As GeographicErr
            Console.WriteLine(String.Format("Caught exception: {0}", ex.Message))
        End Try
    End Sub
End Module

INTERFACE DIFFERENCES:
The LatitudeOrigin, LongitudeOrigin, MajorRadius and Flattening functions are implimented as properties.

Definition at line 70 of file CassiniSoldner.h.

Constructor & Destructor Documentation

CassiniSoldner::!CassiniSoldner ( )

private

Definition at line 22 of file dotnet/NETGeographicLib/CassiniSoldner.cpp.

CassiniSoldner::CassiniSoldner	(	double	lat0,
		double	lon0
	)

Constructor for CassiniSoldner specifying a center point and assuming the WGS84 ellipsoid.

Parameters

[in]	lat0	latitude of center point of projection (degrees).
[in]	lon0	longitude of center point of projection (degrees).

Definition at line 32 of file dotnet/NETGeographicLib/CassiniSoldner.cpp.

CassiniSoldner::CassiniSoldner	(	double	lat0,
		double	lon0,
		Geodesic^	earth
	)

Constructor for CassiniSoldner specifying a center point.

Parameters

[in]	lat0	latitude of center point of projection (degrees).
[in]	lon0	longitude of center point of projection (degrees).
[in]	earth	the Geodesic object to use for geodesic calculations. By default this uses the WGS84 ellipsoid.

lat0 should be in the range [−90°, 90°].

Definition at line 46 of file dotnet/NETGeographicLib/CassiniSoldner.cpp.

NETGeographicLib::CassiniSoldner::~CassiniSoldner ( )

inline

The destructor calls the finalizer.

Definition at line 103 of file CassiniSoldner.h.

Member Function Documentation

void CassiniSoldner::Forward	(	double	lat,
		double	lon,
		[System::Runtime::InteropServices::Out] double%	x,
		[System::Runtime::InteropServices::Out] double%	y,
		[System::Runtime::InteropServices::Out] double%	azi,
		[System::Runtime::InteropServices::Out] double%	rk
	)

Forward projection, from geographic to Cassini-Soldner.

Parameters

[in]	lat	latitude of point (degrees).
[in]	lon	longitude of point (degrees).
[out]	x	easting of point (meters).
[out]	y	northing of point (meters).
[out]	azi	azimuth of easting direction at point (degrees).
[out]	rk	reciprocal of azimuthal northing scale at point.

lat should be in the range [−90°, 90°]. A call to Forward followed by a call to Reverse will return the original (lat, lon) (to within roundoff). The routine does nothing if the origin has not been set.

Definition at line 70 of file dotnet/NETGeographicLib/CassiniSoldner.cpp.

void CassiniSoldner::Forward	(	double	lat,
		double	lon,
		[System::Runtime::InteropServices::Out] double%	x,
		[System::Runtime::InteropServices::Out] double%	y
	)

CassiniSoldner::Forward without returning the azimuth and scale.

Definition at line 99 of file dotnet/NETGeographicLib/CassiniSoldner.cpp.

void CassiniSoldner::Reset	(	double	lat0,
		double	lon0
	)

Set the central point of the projection

Parameters

[in]	lat0	latitude of center point of projection (degrees).
[in]	lon0	longitude of center point of projection (degrees).

lat0 should be in the range [−90°, 90°].

Definition at line 64 of file dotnet/NETGeographicLib/CassiniSoldner.cpp.

void CassiniSoldner::Reverse	(	double	x,
		double	y,
		[System::Runtime::InteropServices::Out] double%	lat,
		[System::Runtime::InteropServices::Out] double%	lon,
		[System::Runtime::InteropServices::Out] double%	azi,
		[System::Runtime::InteropServices::Out] double%	rk
	)

Reverse projection, from Cassini-Soldner to geographic.

Parameters

[in]	x	easting of point (meters).
[in]	y	northing of point (meters).
[out]	lat	latitude of point (degrees).
[out]	lon	longitude of point (degrees).
[out]	azi	azimuth of easting direction at point (degrees).
[out]	rk	reciprocal of azimuthal northing scale at point.

A call to Reverse followed by a call to Forward will return the original (x, y) (to within roundoff), provided that x and y are sufficiently small not to "wrap around" the earth. The routine does nothing if the origin has not been set.

Definition at line 85 of file dotnet/NETGeographicLib/CassiniSoldner.cpp.

void CassiniSoldner::Reverse	(	double	x,
		double	y,
		[System::Runtime::InteropServices::Out] double%	lat,
		[System::Runtime::InteropServices::Out] double%	lon
	)

CassiniSoldner::Reverse without returning the azimuth and scale.

Definition at line 110 of file dotnet/NETGeographicLib/CassiniSoldner.cpp.

Member Data Documentation

property double NETGeographicLib::CassiniSoldner::Flattening { double get()

Returns: f the flattening of the ellipsoid. This is the value inherited from the Geodesic object used in the constructor.

Definition at line 195 of file CassiniSoldner.h.

property double NETGeographicLib::CassiniSoldner::LatitudeOrigin { double get()

Returns: lat0 the latitude of origin (degrees).

Definition at line 178 of file CassiniSoldner.h.

property double NETGeographicLib::CassiniSoldner::LongitudeOrigin { double get()

Returns: lon0 the longitude of origin (degrees).

Definition at line 183 of file CassiniSoldner.h.

GeographicLib::CassiniSoldner* NETGeographicLib::CassiniSoldner::m_pCassiniSoldner

private

Definition at line 74 of file CassiniSoldner.h.

property double NETGeographicLib::CassiniSoldner::MajorRadius { double get()

Returns: a the equatorial radius of the ellipsoid (meters). This is the value inherited from the Geodesic object used in the constructor.

Definition at line 189 of file CassiniSoldner.h.

The documentation for this class was generated from the following files:

Public Member Functions

Public Attributes

Private Member Functions

Private Attributes

Detailed Description

Constructor & Destructor Documentation

Member Function Documentation

Member Data Documentation