org.apache.commons.math3.optim.nonlinear.scalar.gradient
Enum NonLinearConjugateGradientOptimizer.Formula

java.lang.Object
  extended by java.lang.Enum<NonLinearConjugateGradientOptimizer.Formula>
      extended by org.apache.commons.math3.optim.nonlinear.scalar.gradient.NonLinearConjugateGradientOptimizer.Formula
All Implemented Interfaces:
Serializable, Comparable<NonLinearConjugateGradientOptimizer.Formula>
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:

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.

Since:
2.0

Enum Constant Summary
FLETCHER_REEVES
          Fletcher-Reeves formula.
POLAK_RIBIERE
          Polak-Ribière formula.
 
Method Summary
static NonLinearConjugateGradientOptimizer.Formula valueOf(String name)
          Returns the enum constant of this type with the specified name.
static NonLinearConjugateGradientOptimizer.Formula[] values()
          Returns an array containing the constants of this enum type, in the order they are declared.
 
Methods inherited from class java.lang.Enum
clone, compareTo, equals, finalize, getDeclaringClass, hashCode, name, ordinal, toString, valueOf
 
Methods inherited from class java.lang.Object
getClass, notify, notifyAll, wait, wait, wait
 

Enum Constant Detail

FLETCHER_REEVES

public static final NonLinearConjugateGradientOptimizer.Formula FLETCHER_REEVES
Fletcher-Reeves formula.


POLAK_RIBIERE

public static final NonLinearConjugateGradientOptimizer.Formula POLAK_RIBIERE
Polak-Ribière formula.

Method Detail

values

public static NonLinearConjugateGradientOptimizer.Formula[] 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 (NonLinearConjugateGradientOptimizer.Formula c : NonLinearConjugateGradientOptimizer.Formula.values())
    System.out.println(c);

Returns:
an array containing the constants of this enum type, in the order they are declared

valueOf

public static NonLinearConjugateGradientOptimizer.Formula 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.)

Parameters:
name - the name of the enum constant to be returned.
Returns:
the enum constant with the specified name
Throws:
IllegalArgumentException - if this enum type has no constant with the specified name
NullPointerException - if the argument is null


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