org.orekit.propagation.numerical

Class JacobiansMapper

java.lang.Object

org.orekit.propagation.integration.AbstractJacobiansMapper

org.orekit.propagation.numerical.JacobiansMapper

public class JacobiansMapper
extends AbstractJacobiansMapper

Mapper between two-dimensional Jacobian matrices and one-dimensional additional state arrays.

This class does not hold the states by itself. Instances of this class are guaranteed to be immutable.

Author:

Luc Maisonobe

See Also:

PartialDerivativesEquations, NumericalPropagator, SpacecraftState.getAdditionalState(String), AbstractPropagator

Field Summary

Fields

Modifier and Type	Field and Description
static int	STATE_DIMENSION State dimension, fixed to 6.

Method Summary

Modifier and Type	Method and Description
int	getAdditionalStateDimension() Compute the length of the one-dimensional additional state array needed.
protected double[][]	getConversionJacobian(SpacecraftState state) Get the conversion Jacobian between state parameters and parameters used for derivatives.
void	getParametersJacobian(SpacecraftState state, double[][] dYdP) Get the Jacobian with respect to parameters from a one-dimensional additional state array.
void	getStateJacobian(SpacecraftState state, double[][] dYdY0) Get the Jacobian with respect to state from a one-dimensional additional state array.
void	setInitialJacobians(SpacecraftState state, double[][] dY1dY0, double[][] dY1dP, double[] p) Set the Jacobian with respect to state into a one-dimensional additional state array.

Methods inherited from class org.orekit.propagation.integration.AbstractJacobiansMapper

getName, getParameters

Methods inherited from class java.lang.Object

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

Field Detail

STATE_DIMENSION

public static final int STATE_DIMENSION

State dimension, fixed to 6.

Since:

9.0

See Also:

Constant Field Values

Method Detail

getConversionJacobian

protected double[][] getConversionJacobian(SpacecraftState state)

Get the conversion Jacobian between state parameters and parameters used for derivatives.

For a DSST propagator, state parameters and parameters used for derivatives are the same, so the Jocabian is simply the identity.

For Numerical propagator, parameters used for derivatives are cartesian and they can be different from state parameters because the numerical propagator can accept different type of orbits.

Specified by:

getConversionJacobian in class AbstractJacobiansMapper

Parameters:

state - spacecraft state

Returns:

conversion Jacobian

setInitialJacobians

public void setInitialJacobians(SpacecraftState state,
                                double[][] dY1dY0,
                                double[][] dY1dP,
                                double[] p)

Set the Jacobian with respect to state into a one-dimensional additional state array.

This method converts the Jacobians to Cartesian parameters and put the converted data in the one-dimensional p array.

Specified by:

setInitialJacobians in class AbstractJacobiansMapper

Parameters:

state - spacecraft state

dY1dY0 - Jacobian of current state at time t₁ with respect to state at some previous time t₀

dY1dP - Jacobian of current state at time t₁ with respect to parameters (may be null if there are no parameters)

p - placeholder where to put the one-dimensional additional state

See Also:

AbstractJacobiansMapper.getStateJacobian(SpacecraftState, double[][])

getStateJacobian

public void getStateJacobian(SpacecraftState state,
                             double[][] dYdY0)

Get the Jacobian with respect to state from a one-dimensional additional state array.

This method extract the data from the state and put it in the dYdY0 array.

Specified by:

getStateJacobian in class AbstractJacobiansMapper

Parameters:

state - spacecraft state

dYdY0 - placeholder where to put the Jacobian with respect to state

See Also:

AbstractJacobiansMapper.getParametersJacobian(SpacecraftState, double[][])

getParametersJacobian

public void getParametersJacobian(SpacecraftState state,
                                  double[][] dYdP)

Get the Jacobian with respect to parameters from a one-dimensional additional state array.

This method extract the data from the state and put it in the dYdP array.

If no parameters have been set in the constructor, the method returns immediately and does not reference dYdP which can safely be null in this case.

Specified by:

getParametersJacobian in class AbstractJacobiansMapper

Parameters:

state - spacecraft state

dYdP - placeholder where to put the Jacobian with respect to parameters

See Also:

AbstractJacobiansMapper.getStateJacobian(SpacecraftState, double[][])

getAdditionalStateDimension

public int getAdditionalStateDimension()

Compute the length of the one-dimensional additional state array needed.

Specified by:

getAdditionalStateDimension in class AbstractJacobiansMapper

Returns:

length of the one-dimensional additional state array