Enum ConjugateGradientFormula

  • All Implemented Interfaces:
    Serializable, Comparable<ConjugateGradientFormula>

    public enum ConjugateGradientFormula
    extends Enum<ConjugateGradientFormula>
    Available choices of update formulas for the β parameter in NonLinearConjugateGradientOptimizer.

    The β parameter is used to compute the successive conjugate search directions. For non-linear conjugate gradients, there are two formulas to compute β:

    • Fletcher-Reeves formula
    • Polak-Ribière formula
    On the one hand, the Fletcher-Reeves formula is guaranteed to converge if the start point is close enough of the optimum whether the Polak-Ribière formula may not converge in rare cases. On the other hand, the Polak-Ribière formula is often faster when it does converge. Polak-Ribière is often used.

    See Also:
    • Method Detail

      • values

        public static ConjugateGradientFormula[] values()
        Returns an array containing the constants of this enum type, in the order they are declared. This method may be used to iterate over the constants as follows:
        for (ConjugateGradientFormula c : ConjugateGradientFormula.values())
        an array containing the constants of this enum type, in the order they are declared
      • valueOf

        public static ConjugateGradientFormula valueOf​(String name)
        Returns the enum constant of this type with the specified name. The string must match exactly an identifier used to declare an enum constant in this type. (Extraneous whitespace characters are not permitted.)
        name - the name of the enum constant to be returned.
        the enum constant with the specified name
        IllegalArgumentException - if this enum type has no constant with the specified name
        NullPointerException - if the argument is null