NonLinearConjugateGradientOptimizer.Formula (Apache Commons Math 4.0-beta1)

java.lang.Object
- java.lang.Enum<NonLinearConjugateGradientOptimizer.Formula>
- - org.apache.commons.math4.legacy.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:
- 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.
Since:

2.0

Enum Constant Summary

Enum Constants
Enum Constant Description

FLETCHER_REEVES
Fletcher-Reeves formula.

POLAK_RIBIERE
Polak-Ribière formula.

Method Summary

All Methods Static Methods Concrete Methods
Modifier and Type	Method	Description
`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