.NET wrapper for GeographicLib::CircularEngine. More...
#include <NETGeographicLib/CircularEngine.h>
Public Member Functions | |
CircularEngine (const GeographicLib::CircularEngine &c) | |
~CircularEngine () | |
double | LongitudeSum (double coslon, double sinlon) |
double | LongitudeSum (double lon) |
double | LongitudeSum (double coslon, double sinlon,[System::Runtime::InteropServices::Out] double% gradx,[System::Runtime::InteropServices::Out] double% grady,[System::Runtime::InteropServices::Out] double% gradz) |
double | LongitudeSum (double lon,[System::Runtime::InteropServices::Out] double% gradx,[System::Runtime::InteropServices::Out] double% grady,[System::Runtime::InteropServices::Out] double% gradz) |
.NET wrapper for GeographicLib::CircularEngine.
This class allows .NET applications to access GeographicLib::CircularEngine.
The class is a companion to SphericalEngine. If the results of a spherical harmonic sum are needed for several points on a circle of constant latitude lat and height h, then SphericalEngine::Circle can compute the inner sum, which is independent of longitude lon, and produce a CircularEngine object. CircularEngine::LongitudeSum() can then be used to perform the outer sum for particular values of lon. This can lead to substantial improvements in computational speed for high degree sum (approximately by a factor of N / 2 where N is the maximum degree).
CircularEngine is tightly linked to the internals of SphericalEngine. For that reason, the constructor for this class is for internal use only. Use SphericalHarmonic::Circle, SphericalHarmonic1::Circle, and SphericalHarmonic2::Circle to create instances of this class.
CircularEngine stores the coefficients needed to allow the summation over order to be performed in 2 or 6 vectors of length M + 1 (depending on whether gradients are to be calculated). For this reason the constructor may throw a GeographicErr exception.
C# Example:
using System; using NETGeographicLib; namespace example_CircularEngine { class Program { static void Main(string[] args) { // This computes the same value as example-SphericalHarmonic.cpp using a // CircularEngine (which will be faster if many values on a circle of // latitude are to be found). try { int N = 3; // The maxium degree double[] ca = {10, 9, 8, 7, 6, 5, 4, 3, 2, 1}; // cosine coefficients double[] sa = {6, 5, 4, 3, 2, 1}; // sine coefficients double a = 1; SphericalHarmonic h = new SphericalHarmonic(ca, sa, N, a, SphericalHarmonic.Normalization.SCHMIDT); double x = 2, y = 3, z = 1, p = Math.Sqrt(x*x+y*y); CircularEngine circ = h.Circle(p, z, true); double v, vx, vy, vz; v = circ.LongitudeSum(x/p, y/p, out vx, out vy, out vz); Console.WriteLine(String.Format("{0} {1} {2} {3}", v, vx, vy, vz)); } catch (GeographicErr e) { Console.WriteLine(String.Format("Caught exception: {0}", e.Message)); } } } }
Managed C++ Example:
using namespace System; using namespace NETGeographicLib; int main(array<System::String ^> ^/*args*/) { // This computes the same value as example-SphericalHarmonic.cpp using a // CircularEngine (which will be faster if many values on a circle of // latitude are to be found). try { int N = 3; // The maxium degree array<double>^ ca = {10, 9, 8, 7, 6, 5, 4, 3, 2, 1}; // cosine coefficients array<double>^ sa = {6, 5, 4, 3, 2, 1}; // sine coefficients double a = 1; SphericalHarmonic^ h = gcnew SphericalHarmonic(ca, sa, N, a, SphericalHarmonic::Normalization::SCHMIDT); double x = 2, y = 3, z = 1, p = Math::Sqrt(x*x+y*y); CircularEngine^ circ = h->Circle(p, z, true); double v, vx, vy, vz; v = circ->LongitudeSum(x/p, y/p, vx, vy, vz); Console::WriteLine(String::Format("{0} {1} {2} {3}", v, vx, vy, vz)); } catch (GeographicErr^ e) { Console::WriteLine(String::Format("Caught exception: {0}", e->Message)); return -1; } return 0; }
Visual Basic Example:
Imports NETGeographicLib Module example_CircularEngine Sub Main() ' This computes the same value as example-SphericalHarmonic.cpp using a ' CircularEngine (which will be faster if many values on a circle of ' latitude are to be found). Try Dim N As Integer = 3 ' The maxium degree Dim ca As Double() = {10, 9, 8, 7, 6, 5, 4, 3, 2, 1} ' cosine coefficients Dim sa As Double() = {6, 5, 4, 3, 2, 1} ' sine coefficients Dim a As Double = 1 Dim h As SphericalHarmonic = New SphericalHarmonic(ca, sa, N, a, SphericalHarmonic.Normalization.SCHMIDT) Dim x As Double = 2, y = 3, z = 1, p = Math.Sqrt(x * x + y * y) Dim circ As CircularEngine = h.Circle(p, z, True) Dim v, vx, vy, vz As Double v = circ.LongitudeSum(x / p, y / p, vx, vy, vz) Console.WriteLine(String.Format("{0} {1} {2} {3}", v, vx, vy, vz)) Catch ex As GeographicErr Console.WriteLine(String.Format("Caught exception: {0}", ex.Message)) End Try End Sub End Module
INTERFACE DIFFERENCES:
The () operator has been replaced with with LongitudeSum.
This class does not have a constructor that can be used in a .NET application. Use SphericalHarmonic::Circle, SphericalHarmonic1::Circle or SphericalHarmonic2::Circle to create instances of this class.
Definition at line 54 of file CircularEngine.h.
NETGeographicLib::CircularEngine::CircularEngine | ( | const GeographicLib::CircularEngine & | c | ) |
The constructor.
This constructor should not be used in .NET applications. Use SphericalHarmonic::Circle, SphericalHarmonic1::Circle or SphericalHarmonic2::Circle to create instances of this class.
[in] | c | The unmanaged CircularEngine to be copied. |
Referenced by ~CircularEngine().
NETGeographicLib::CircularEngine::~CircularEngine | ( | ) | [inline] |
The destructor calls the finalizer
Definition at line 77 of file CircularEngine.h.
References CircularEngine().
double NETGeographicLib::CircularEngine::LongitudeSum | ( | double | coslon, | |
double | sinlon | |||
) |
Evaluate the sum for a particular longitude given in terms of its cosine and sine.
[in] | coslon | the cosine of the longitude. |
[in] | sinlon | the sine of the longitude. |
The arguments must satisfy coslon2 + sinlon2 = 1.
double NETGeographicLib::CircularEngine::LongitudeSum | ( | double | lon | ) |
Evaluate the sum for a particular longitude.
[in] | lon | the longitude (degrees). |
double NETGeographicLib::CircularEngine::LongitudeSum | ( | double | coslon, | |
double | sinlon, | |||
[System::Runtime::InteropServices::Out] double% | gradx, | |||
[System::Runtime::InteropServices::Out] double% | grady, | |||
[System::Runtime::InteropServices::Out] double% | gradz | |||
) |
Evaluate the sum and its gradient for a particular longitude given in terms of its cosine and sine.
[in] | coslon | the cosine of the longitude. |
[in] | sinlon | the sine of the longitude. |
[out] | gradx | x component of the gradient. |
[out] | grady | y component of the gradient. |
[out] | gradz | z component of the gradient. |
The gradients will only be computed if the CircularEngine object was created with this capability (e.g., via gradp = true in SphericalHarmonic::Circle). If not, gradx, etc., will not be touched. The arguments must satisfy coslon2 + sinlon2 = 1.
double NETGeographicLib::CircularEngine::LongitudeSum | ( | double | lon, | |
[System::Runtime::InteropServices::Out] double% | gradx, | |||
[System::Runtime::InteropServices::Out] double% | grady, | |||
[System::Runtime::InteropServices::Out] double% | gradz | |||
) |
Evaluate the sum and its gradient for a particular longitude.
[in] | lon | the longitude (degrees). |
[out] | gradx | x component of the gradient. |
[out] | grady | y component of the gradient. |
[out] | gradz | z component of the gradient. |
The gradients will only be computed if the CircularEngine object was created with this capability (e.g., via gradp = true in SphericalHarmonic::Circle). If not, gradx, etc., will not be touched.