Class JacobiansMapper

    • 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 DSST and TLE propagators, state parameters and parameters used for derivatives are the same, so the Jacobian 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.

        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[][])
      • 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[][])