agi.foundation.coordinates

(agi.foundation.core-2024r3.jar)

Class DiagonalMatrix

java.lang.Object

agi.foundation.infrastructure.DefinitionalObject

agi.foundation.coordinates.Matrix

agi.foundation.coordinates.DiagonalMatrix

All Implemented Interfaces:

ICloneWithContext, IEnumerateDependencies, IEquatableDefinition, IEquatableEpsilon<Matrix>, IFreezable

public class DiagonalMatrix
extends Matrix

An implementation of a square Matrix whose diagonal elements are the only ones with a non-zero value.

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	DiagonalMatrix(DiagonalMatrix existingInstance, CopyContext context) Initializes a new instance as a copy of an existing instance.
	DiagonalMatrix(double[] array) Initializes a new instance which has the dimension of the length of the given array, and whose diagonal elements take on the values of the contents of the array.
	DiagonalMatrix(int dimension) Initializes a new instance with the given dimension.
	DiagonalMatrix(int dimension, double value) Initializes a new instance with the given dimension.

Method Summary

Modifier and Type	Method and Description
protected boolean	checkForSameDefinition(DiagonalMatrix other) Checks to determine if another instance has the same definition as this instance and returns true if it does.
protected boolean	checkForSameDefinition(Matrix other) Checks to determine if another instance has the same definition as this instance and returns true if it does.
Object	clone(CopyContext context) Clones this object using the specified context.
protected int	computeCurrentDefinitionHashCode() Computes a hash code based on the current properties of this object.
boolean	equals(Object obj) Indicates whether another object is exactly equal to this instance.
double	get(int rowIndex, int columnIndex) Gets the value of the element at the given location.
int	hashCode() Returns a hash code for this instance, which is suitable for use in hashing algorithms and data structures like a hash table.
Matrix	multiply(double factor) Creates a new Matrix which has the value of the current matrix multiplied by the given factor.
void	set(int rowIndex, int columnIndex, double value) Sets the value of the element at the given location.
Matrix	transpose() Creates a new Matrix which is the transpose of the current matrix.

Methods inherited from class agi.foundation.coordinates.Matrix

add, add, add, add, add, addAssign, checkForSameDefinition, elementDivide, elementDivide, elementDivide, elementDivide, elementDivide, elementDivideAssign, elementMultiply, elementMultiply, elementMultiply, elementMultiply, elementMultiply, elementMultiplyAssign, equals, equalsEpsilon, getColumnDimension, getFrozenCopy, getMatrix, getMatrix, getMatrix, getMatrix, getMatrix, getMatrix, getMatrix, getMatrix, getRowDimension, multiply, multiply, multiply, multiply, multiply, multiply, multiply, multiplyAssign, setMatrix, setMatrix, setMatrix, setMatrix, setMatrix, subtract, subtract, subtract, subtract, subtract, subtractAssign, toString

Methods inherited from class agi.foundation.infrastructure.DefinitionalObject

areSameDefinition, areSameDefinition, areSameDefinition, areSameDefinition, areSameDefinition, collectionItemsAreSameDefinition, collectionItemsAreSameDefinition, collectionItemsAreSameDefinition, dictionaryItemsAreSameDefinition, enumerateDependencies, freeze, freezeAggregatedObjects, getCollectionHashCode, getCollectionHashCode, getCollectionHashCode, getDefinitionHashCode, getDefinitionHashCode, getDefinitionHashCode, getDefinitionHashCode, getDefinitionHashCode, getDefinitionHashCode, getDictionaryHashCode, getIsFrozen, isSameDefinition, throwIfFrozen

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Constructor Detail

DiagonalMatrix

public DiagonalMatrix(int dimension)

Initializes a new instance with the given dimension. All elements of the matrix will be zero.

Parameters:

dimension - The row and column dimension of the matrix.

DiagonalMatrix

public DiagonalMatrix(int dimension,
                      double value)

Initializes a new instance with the given dimension. All diagonal elements are set to the given value.

Parameters:

dimension - The row and column dimension of the matrix.

value - The value that all diagonal elements will take.

DiagonalMatrix

public DiagonalMatrix(@Nonnull
                      double[] array)

Initializes a new instance which has the dimension of the length of the given array, and whose diagonal elements take on the values of the contents of the array.

Parameters:

array - The created matrix will have a row and column dimension equal to the length of this array, and the diagonal elements of the matrix will be equal to the elements of this array.

Throws:

ArgumentNullException - Thrown when array is null.

DiagonalMatrix

protected DiagonalMatrix(@Nonnull
                         DiagonalMatrix existingInstance,
                         @Nonnull
                         CopyContext context)

Initializes a new instance as a copy of an existing instance.

See ICloneWithContext.clone(CopyContext) for more information about how to implement this constructor in a derived class.

Parameters:

existingInstance - The existing instance to copy.

context - A CopyContext that controls the depth of the copy.

Throws:

ArgumentNullException - Thrown when existingInstance or context is null.

Method Detail

clone

public Object clone(CopyContext context)

Clones this object using the specified context.

This method should be implemented to call a copy constructor on the class of the object being cloned. The copy constructor should take the CopyContext as a parameter in addition to the existing instance to copy. The copy constructor should first call CopyContext.addObjectMapping(T, T) to identify the newly constructed instance as a copy of the existing instance. It should then copy all fields, using CopyContext.updateReference(T) to copy any reference fields.

A typical implementation of ICloneWithContext:

public static class MyClass implements ICloneWithContext {
    public MyClass(MyClass existingInstance, CopyContext context) {
        context.addObjectMapping(existingInstance, this);
        someReference = context.updateReference(existingInstance.someReference);
    }

    @Override
    public final Object clone(CopyContext context) {
        return new MyClass(this, context);
    }

    private Object someReference;
}

In general, all fields that are reference types should be copied with a call to CopyContext.updateReference(T). There are a couple of exceptions:

1. Fields that are aggregate parts of the object should always be copied. A referenced object is an aggregate if properties or methods on the object being copied can modify the externally-visible value of the referenced object.
2. If the semantics of the referenced object require that it have a single parent, owner, context, etc., and the object being copied is that parent, owner, or context, then the referenced object should always be copied.

If one of these exceptions applies, the CopyContext should be given an opportunity to update the reference before the reference is copied explicitly. Use CopyContext.updateReference(T) to update the reference. If CopyContext.updateReference(T) returns the original object, indicating that the context does not have a replacement registered, then copy the object manually by invoking a Clone method, a copy constructor, or by manually constructing a new instance and copying the values.

alwaysCopy = context.updateReference(existingInstance.alwaysCopy);
if (existingInstance.alwaysCopy != null && alwaysCopy == existingInstance.alwaysCopy) {
    alwaysCopy = (AlwaysCopy) existingInstance.alwaysCopy.clone(context);
}

If you are implementing an evaluator (a class that implements IEvaluator), the IEvaluator.updateEvaluatorReferences(agi.foundation.infrastructure.CopyContext) method shares some responsibilities with the copy context constructor. Code duplication can be avoided by doing the following:

1. For references to other evaluators ONLY, simply assign the reference in the constructor instead of calling CopyContext.updateReference(T). You should still call CopyContext.updateReference(T) on any references to non-evaluators.
2. Call IEvaluator.updateEvaluatorReferences(agi.foundation.infrastructure.CopyContext) as the last line in the constructor and pass it the same CopyContext passed to the constructor.
3. Implement IEvaluator.updateEvaluatorReferences(agi.foundation.infrastructure.CopyContext) as normal. See the reference documentation for IEvaluator.updateEvaluatorReferences(agi.foundation.infrastructure.CopyContext) for more information on implementing that method.

public MyClass(MyClass existingInstance, CopyContext context) {
    super(existingInstance, context);
    someReference = context.updateReference(existingInstance.someReference);
    evaluatorReference = existingInstance.evaluatorReference;
    updateEvaluatorReferences(context);
}

@Override
public void updateEvaluatorReferences(CopyContext context) {
    evaluatorReference = context.updateReference(evaluatorReference);
}

@Override
public Object clone(CopyContext context) {
    return new MyClass(this, context);
}

private Object someReference;
private IEvaluator evaluatorReference;

Specified by:

clone in interface ICloneWithContext

Specified by:

clone in class DefinitionalObject

Parameters:

context - The context to use to perform the copy.

Returns:

A new instance which is a copy of this object.

checkForSameDefinition

protected final boolean checkForSameDefinition(Matrix other)

Checks to determine if another instance has the same definition as this instance and returns true if it does. Derived classes MUST override this method and check all new fields introduced by the derived class for definitional equivalence. It is NOT necessary to check base class fields because the base class will already have done that. When overriding this method, you should NOT call the base implementation because it will return false for all derived-class instances. Derived classes should check the type of other to preserve the symmetric nature of IEquatableDefinition.isSameDefinition(java.lang.Object).

Specified by:

checkForSameDefinition in class Matrix

Parameters:

other - The other instance to compare to this one.

Returns:

true if the two objects are defined equivalently; otherwise false.

checkForSameDefinition

protected boolean checkForSameDefinition(DiagonalMatrix other)

Checks to determine if another instance has the same definition as this instance and returns true if it does. Derived classes MUST override this method and check all new fields introduced by the derived class for definitional equivalence. It is NOT necessary to check base class fields because the base class will already have done that. When overriding this method, you should NOT call the base implementation because it will return false for all derived-class instances. Derived classes should check the type of other to preserve the symmetric nature of IEquatableDefinition.isSameDefinition(java.lang.Object).

Parameters:

other - The other instance to compare to this one.

Returns:

true if the two objects are defined equivalently; otherwise false.

computeCurrentDefinitionHashCode

protected int computeCurrentDefinitionHashCode()

Computes a hash code based on the current properties of this object. Derived classes MUST override this method and compute a hash code that combines: a unique hash code seed, the base implementation result, and the hash codes of all new fields introduced by the derived class which are used in the DiagonalMatrix.checkForSameDefinition(agi.foundation.coordinates.Matrix) method.

Overrides:

computeCurrentDefinitionHashCode in class Matrix

Returns:

The computed hash code.

equals

public boolean equals(Object obj)

Indicates whether another object is exactly equal to this instance.

Overrides:

equals in class Object

Parameters:

obj - The object to compare to this instance.

Returns:

true if obj is an instance of this type and represents the same value as this instance; otherwise false.

See Also:

Object.hashCode(), HashMap

hashCode

public int hashCode()

Returns a hash code for this instance, which is suitable for use in hashing algorithms and data structures like a hash table.

Overrides:

hashCode in class Object

Returns:

A hash code for the current object.

See Also:

Object.equals(java.lang.Object), System.identityHashCode(java.lang.Object)

transpose

public Matrix transpose()

Creates a new Matrix which is the transpose of the current matrix.

Specified by:

transpose in class Matrix

Returns:

The new matrix.

multiply

public Matrix multiply(double factor)

Creates a new Matrix which has the value of the current matrix multiplied by the given factor.

Specified by:

multiply in class Matrix

Parameters:

factor - The 'scalar' to multiply by the current Matrix.

Returns:

The new matrix.

get

public double get(int rowIndex,
                  int columnIndex)

Gets the value of the element at the given location.

Specified by:

get in class Matrix

Parameters:

rowIndex - The row index of the desired element.

columnIndex - The column index of the desired element.

Returns:

The value of the element at the given location.

Throws:

IllegalStateException - Thrown when an attempt is made to set a non-diagonal element.

set

public void set(int rowIndex,
                int columnIndex,
                double value)

Sets the value of the element at the given location.

Specified by:

set in class Matrix

Parameters:

rowIndex - The row index of the desired element.

columnIndex - The column index of the desired element.

Throws:

IllegalStateException - Thrown when an attempt is made to set a non-diagonal element.