Spherical harmonic series with a correction to the coefficients. More...

#include <GeographicLib/SphericalHarmonic1.hpp>

Public Types
enum	normalization { FULL , SCHMIDT }

Public Member Functions
	SphericalHarmonic1 (const std::vector< real > &C, const std::vector< real > &S, int N, const std::vector< real > &C1, const std::vector< real > &S1, int N1, real a, unsigned norm=FULL)

	SphericalHarmonic1 (const std::vector< real > &C, const std::vector< real > &S, int N, int nmx, int mmx, const std::vector< real > &C1, const std::vector< real > &S1, int N1, int nmx1, int mmx1, real a, unsigned norm=FULL)

	SphericalHarmonic1 ()

Math::real	operator() (real tau, real x, real y, real z) const

Math::real	operator() (real tau, real x, real y, real z, real &gradx, real &grady, real &gradz) const

CircularEngine	Circle (real tau, real p, real z, bool gradp) const

const SphericalEngine::coeff &	Coefficients () const

const SphericalEngine::coeff &	Coefficients1 () const

Detailed Description

Spherical harmonic series with a correction to the coefficients.

This classes is similar to SphericalHarmonic, except that the coefficients C_nm are replaced by C_nm + tau C'_nm (and similarly for S_nm).

Example of use:

// Example of using the GeographicLib::SphericalHarmonic1 class
 
#include <iostream>
#include <exception>
#include <vector>
#include <GeographicLib/SphericalHarmonic1.hpp>
 
using namespace std;
using namespace GeographicLib;
 
int main() {
  try {
    int N = 3, N1 = 2;                  // The maxium degrees
    double ca[] = {10, 9, 8, 7, 6, 5, 4, 3, 2, 1}; // cosine coefficients
    vector<double> C(ca, ca + (N + 1) * (N + 2) / 2);
    double sa[] = {6, 5, 4, 3, 2, 1}; // sine coefficients
    vector<double> S(sa, sa + N * (N + 1) / 2);
    double cb[] = {1, 2, 3, 4, 5, 6};
    vector<double> C1(cb, cb + (N1 + 1) * (N1 + 2) / 2);
    double sb[] = {3, 2, 1};
    vector<double> S1(sb, sb + N1 * (N1 + 1) / 2);
    double a = 1;
    SphericalHarmonic1 h(C, S, N, C1, S1, N1, a);
    double tau = 0.1, x = 2, y = 3, z = 1;
    double v, vx, vy, vz;
    v = h(tau, x, y, z, vx, vy, vz);
    cout << v << " " << vx << " " << vy << " " << vz << "\n";
  }
  catch (const exception& e) {
    cerr << "Caught exception: " << e.what() << "\n";
    return 1;
  }
}

Definition at line 32 of file SphericalHarmonic1.hpp.

Member Enumeration Documentation

◆ normalization

enum GeographicLib::SphericalHarmonic1::normalization

Supported normalizations for associate Legendre polynomials.

Enumerator
FULL	Fully normalized associated Legendre polynomials. See SphericalHarmonic::FULL for documentation.
SCHMIDT	Schmidt semi-normalized associated Legendre polynomials. See SphericalHarmonic::SCHMIDT for documentation.

Definition at line 37 of file SphericalHarmonic1.hpp.

Constructor & Destructor Documentation

◆ SphericalHarmonic1() [1/3]

GeographicLib::SphericalHarmonic1::SphericalHarmonic1	(	const std::vector< real > &	C,
		const std::vector< real > &	S,
		int	N,
		const std::vector< real > &	C1,
		const std::vector< real > &	S1,
		int	N1,
		real	a,
		unsigned	norm = `FULL`
	)

inline

Constructor with a full set of coefficients specified.

Parameters

[in]	C	the coefficients C_nm.
[in]	S	the coefficients S_nm.
[in]	N	the maximum degree and order of the sum
[in]	C1	the coefficients C'_nm.
[in]	S1	the coefficients S'_nm.
[in]	N1	the maximum degree and order of the correction coefficients C'_nm and S'_nm.
[in]	a	the reference radius appearing in the definition of the sum.
[in]	norm	the normalization for the associated Legendre polynomials, either SphericalHarmonic1::FULL (the default) or SphericalHarmonic1::SCHMIDT.

Exceptions

GeographicErr	if N and N1 do not satisfy N ≥ N1 ≥ −1.
GeographicErr	if any of the vectors of coefficients is not large enough.

See SphericalHarmonic for the way the coefficients should be stored.

The class stores pointers to the first elements of C, S, C', and S'. These arrays should not be altered or destroyed during the lifetime of a SphericalHarmonic object.

Definition at line 88 of file SphericalHarmonic1.hpp.

◆ SphericalHarmonic1() [2/3]

GeographicLib::SphericalHarmonic1::SphericalHarmonic1	(	const std::vector< real > &	C,
		const std::vector< real > &	S,
		int	N,
		int	nmx,
		int	mmx,
		const std::vector< real > &	C1,
		const std::vector< real > &	S1,
		int	N1,
		int	nmx1,
		int	mmx1,
		real	a,
		unsigned	norm = `FULL`
	)

inline

Constructor with a subset of coefficients specified.

Parameters

[in]	C	the coefficients C_nm.
[in]	S	the coefficients S_nm.
[in]	N	the degree used to determine the layout of C and S.
[in]	nmx	the maximum degree used in the sum. The sum over n is from 0 thru nmx.
[in]	mmx	the maximum order used in the sum. The sum over m is from 0 thru min(n, mmx).
[in]	C1	the coefficients C'_nm.
[in]	S1	the coefficients S'_nm.
[in]	N1	the degree used to determine the layout of C' and S'.
[in]	nmx1	the maximum degree used for C' and S'.
[in]	mmx1	the maximum order used for C' and S'.
[in]	a	the reference radius appearing in the definition of the sum.
[in]	norm	the normalization for the associated Legendre polynomials, either SphericalHarmonic1::FULL (the default) or SphericalHarmonic1::SCHMIDT.

Exceptions

GeographicErr	if the parameters do not satisfy N ≥ nmx ≥ mmx ≥ −1; N1 ≥ nmx1 ≥ mmx1 ≥ −1; N ≥ N1; nmx ≥ nmx1; mmx ≥ mmx1.
GeographicErr	if any of the vectors of coefficients is not large enough.

The class stores pointers to the first elements of C, S, C', and S'. These arrays should not be altered or destroyed during the lifetime of a SphericalHarmonic object.

Definition at line 134 of file SphericalHarmonic1.hpp.

◆ SphericalHarmonic1() [3/3]

GeographicLib::SphericalHarmonic1::SphericalHarmonic1 ( )

inline

A default constructor so that the object can be created when the constructor for another object is initialized. This default object can then be reset with the default copy assignment operator.

Definition at line 156 of file SphericalHarmonic1.hpp.

Member Function Documentation

◆ operator()() [1/2]

Math::real GeographicLib::SphericalHarmonic1::operator()	(	real	tau,
		real	x,
		real	y,
		real	z
	)		const

inline

Compute a spherical harmonic sum with a correction term.

Parameters

[in]	tau	multiplier for correction coefficients C' and S'.
[in]	x	cartesian coordinate.
[in]	y	cartesian coordinate.
[in]	z	cartesian coordinate.

Returns: V the spherical harmonic sum.

This routine requires constant memory and thus never throws an exception.

Definition at line 170 of file SphericalHarmonic1.hpp.

◆ operator()() [2/2]

Math::real GeographicLib::SphericalHarmonic1::operator()	(	real	tau,
		real	x,
		real	y,
		real	z,
		real &	gradx,
		real &	grady,
		real &	gradz
	)		const

inline

Compute a spherical harmonic sum with a correction term and its gradient.

Parameters

[in]	tau	multiplier for correction coefficients C' and S'.
[in]	x	cartesian coordinate.
[in]	y	cartesian coordinate.
[in]	z	cartesian coordinate.
[out]	gradx	x component of the gradient
[out]	grady	y component of the gradient
[out]	gradz	z component of the gradient

Returns: V the spherical harmonic sum.

This is the same as the previous function, except that the components of the gradients of the sum in the x, y, and z directions are computed. This routine requires constant memory and thus never throws an exception.

Definition at line 206 of file SphericalHarmonic1.hpp.

◆ Circle()

CircularEngine GeographicLib::SphericalHarmonic1::Circle	(	real	tau,
		real	p,
		real	z,
		bool	gradp
	)		const

inline

Create a CircularEngine to allow the efficient evaluation of several points on a circle of latitude at a fixed value of tau.

Parameters

[in]	tau	the multiplier for the correction coefficients.
[in]	p	the radius of the circle.
[in]	z	the height of the circle above the equatorial plane.
[in]	gradp	if true the returned object will be able to compute the gradient of the sum.

Exceptions

std::bad_alloc if the memory for the CircularEngine can't be allocated.

Returns: the CircularEngine object.

SphericalHarmonic1::operator()() exchanges the order of the sums in the definition, i.e., ∑_{n = 0..N} ∑_{m = 0..n} becomes ∑_{m = 0..N} ∑_{n = m..N}. SphericalHarmonic1::Circle performs the inner sum over degree n (which entails about N² operations). Calling CircularEngine::operator()() on the returned object performs the outer sum over the order m (about N operations).

See SphericalHarmonic::Circle for an example of its use.

Definition at line 248 of file SphericalHarmonic1.hpp.

Referenced by GeographicLib::GravityModel::Circle().

◆ Coefficients()

const SphericalEngine::coeff & GeographicLib::SphericalHarmonic1::Coefficients ( ) const

inline

Returns: the zeroth SphericalEngine::coeff object.

Definition at line 272 of file SphericalHarmonic1.hpp.

◆ Coefficients1()

const SphericalEngine::coeff & GeographicLib::SphericalHarmonic1::Coefficients1 ( ) const

inline

Returns: the first SphericalEngine::coeff object.

Definition at line 277 of file SphericalHarmonic1.hpp.

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

SphericalHarmonic1.hpp

Public Types

Public Member Functions

Detailed Description

Member Enumeration Documentation

◆ normalization

Constructor & Destructor Documentation

◆ SphericalHarmonic1() [1/3]

◆ SphericalHarmonic1() [2/3]

◆ SphericalHarmonic1() [3/3]

Member Function Documentation

◆ operator()() [1/2]

◆ operator()() [2/2]

◆ Circle()

◆ Coefficients()

◆ Coefficients1()