org.orekit.propagation.semianalytical.dsst.utilities

Class JacobiPolynomials

java.lang.Object

org.orekit.propagation.semianalytical.dsst.utilities.JacobiPolynomials

public class JacobiPolynomials
extends Object

Provider of the Jacobi polynomials P_l^v,w.

This class is used for tesseral contribution computation and DSSTThirdBody.

Since:

6.1

Author:

Nicolas Bernard

Method Summary

Modifier and Type	Method and Description
static <T extends org.hipparchus.CalculusFieldElement<T>> org.hipparchus.analysis.differentiation.FieldGradient<T>	getValue(int l, int v, int w, org.hipparchus.analysis.differentiation.FieldGradient<T> gamma) Returns the value and derivatives of the Jacobi polynomial Plv,w evaluated at γ.
static org.hipparchus.analysis.differentiation.Gradient	getValue(int l, int v, int w, org.hipparchus.analysis.differentiation.Gradient gamma) Returns the value and derivatives of the Jacobi polynomial Plv,w evaluated at γ.
static double[]	getValueAndDerivative(int l, int v, int w, double x) Returns the value and derivatives of the Jacobi polynomial Plv,w evaluated at γ.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Detail

getValueAndDerivative

public static double[] getValueAndDerivative(int l,
                                             int v,
                                             int w,
                                             double x)

Returns the value and derivatives of the Jacobi polynomial P_l^v,w evaluated at γ.

This method is guaranteed to be thread-safe

It was added to improve performances of DSST propagation with tesseral gravity field or third-body perturbations.

See issue 1098.

It appeared the "Gradient" version was degrading performances. This last was however kept for validation purposes.

Parameters:

l - degree of the polynomial

v - v value

w - w value

x - x value

Returns:

value and derivatives of the Jacobi polynomial P_l^v,w(γ)

Since:

11.3.3

getValue

public static org.hipparchus.analysis.differentiation.Gradient getValue(int l,
                                                                        int v,
                                                                        int w,
                                                                        org.hipparchus.analysis.differentiation.Gradient gamma)

Returns the value and derivatives of the Jacobi polynomial P_l^v,w evaluated at γ.

This method is guaranteed to be thread-safe

It's not used in the code anymore, see getValueAndDerivative(int, int, int, double), but was kept for validation purpose.

Parameters:

l - degree of the polynomial

v - v value

w - w value

gamma - γ value

Returns:

value and derivatives of the Jacobi polynomial P_l^v,w(γ)

Since:

10.2

getValue

public static <T extends org.hipparchus.CalculusFieldElement<T>> org.hipparchus.analysis.differentiation.FieldGradient<T> getValue(int l,
                                                                                                                                   int v,
                                                                                                                                   int w,
                                                                                                                                   org.hipparchus.analysis.differentiation.FieldGradient<T> gamma)

Returns the value and derivatives of the Jacobi polynomial P_l^v,w evaluated at γ.

This method is guaranteed to be thread-safe

Type Parameters:

T - the type of the field elements

Parameters:

l - degree of the polynomial

v - v value

w - w value

gamma - γ value

Returns:

value and derivatives of the Jacobi polynomial P_l^v,w(γ)

Since:

10.2