Enum NonLinearConjugateGradientOptimizer.Formula

java.lang.Object
java.lang.Enum<NonLinearConjugateGradientOptimizer.Formula>
org.hipparchus.optim.nonlinear.scalar.gradient.NonLinearConjugateGradientOptimizer.Formula
All Implemented Interfaces:
Serializable, Comparable<NonLinearConjugateGradientOptimizer.Formula>, java.lang.constant.Constable
Enclosing class:
NonLinearConjugateGradientOptimizer

public static enum NonLinearConjugateGradientOptimizer.Formula extends Enum<NonLinearConjugateGradientOptimizer.Formula>
Available choices of update formulas for the updating the parameter that is used to compute the successive conjugate search directions. For non-linear conjugate gradients, there are two formulas:
  • 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.