agi.foundation.numericalmethods

(agi.foundation.core-2024r2.jar)

Enum FiniteDifferenceMethod

java.lang.Object

java.lang.Enum<FiniteDifferenceMethod>

agi.foundation.numericalmethods.FiniteDifferenceMethod

All Implemented Interfaces:

Enumeration, Serializable, Comparable<FiniteDifferenceMethod>

public enum FiniteDifferenceMethod
extends Enum<FiniteDifferenceMethod>
implements Enumeration

When numerically computing the derivative of a function, this will indicate if the finite difference method should be forward, backwards or central.

Enum Constant Summary

Enum Constants

Enum Constant and Description
BACKWARD A backwards difference method will be performed.
CENTRAL A central difference method will be performed.
FORWARD A forward difference method will be performed.
SIGNED The difference will be the signed perturbation value.

Method Summary

Modifier and Type	Method and Description
static FiniteDifferenceMethod	getDefault() Get the enum constant that is considered to be the default.
static FiniteDifferenceMethod	getFromValue(int value) Get the enum constant that is associated with the given numeric value.
int	getValue() Get the numeric value associated with this enum constant.
static FiniteDifferenceMethod	valueOf(String name) Returns the enum constant of this type with the specified name.
static FiniteDifferenceMethod[]	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

FORWARD

public static final FiniteDifferenceMethod FORWARD

A forward difference method will be performed. When perturbing a variable, the perturbation will be added to the current value of that variable. The total number of function evaluations that will be performed to solve for the Jacobian of a multivariable function will be 1 plus the number of variables.

BACKWARD

public static final FiniteDifferenceMethod BACKWARD

A backwards difference method will be performed. When perturbing a variable, the perturbation will be subtracted to the current value of that variable. The total number of function evaluations that will be performed to solve for the Jacobian of a multivariable function will be 1 plus the number of variables.

SIGNED

public static final FiniteDifferenceMethod SIGNED

The difference will be the signed perturbation value. The total number of function evaluations that will be performed to solve for the Jacobian of a multivariable function will be 1 plus the number of variables.

CENTRAL

public static final FiniteDifferenceMethod CENTRAL

A central difference method will be performed. Two function evaluations will be performed for each variable to determine the change of the function values. One run will be done where half of the perturbation value is subtracted from the nominal value of the variable, and a second run where half of the perturbation value is added to the variable. The total number of function evaluations that will be performed to solve for the Jacobian of a multivariable function will be 1 plus twice the number of variables.

Method Detail

values

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

Returns:

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

valueOf

public static FiniteDifferenceMethod 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

getValue

public int getValue()

Get the numeric value associated with this enum constant.

Specified by:

getValue in interface Enumeration

Returns:

A numeric value.

getFromValue

@Nonnull
public static FiniteDifferenceMethod getFromValue(int value)

Get the enum constant that is associated with the given numeric value.

Parameters:

value - a numeric value.

Returns:

The enum constant associated with value.

getDefault

@Nonnull
public static FiniteDifferenceMethod getDefault()

Get the enum constant that is considered to be the default.

Returns:

The default enum constant.