Class Equation

java.lang.Object

org.ojalgo.equation.Equation

All Implemented Interfaces:

Comparable<Equation>, Access1D<Double>, Mutate1D.Modifiable<Double>, Structure1D

public final class Equation
extends Object
implements Comparable<Equation>, Access1D<Double>, Mutate1D.Modifiable<Double>

Nested Class Summary

Nested classes/interfaces inherited from interface Access1D

Access1D.Aggregatable<N>, Access1D.Collectable<N,R>, Access1D.ElementView<N>, Access1D.SelectionView<N>, Access1D.Sliceable<N>, Access1D.Visitable<N>

Nested classes/interfaces inherited from interface Structure1D

Structure1D.BasicMapper<T>, Structure1D.IndexMapper<T>, Structure1D.IntIndex, Structure1D.Logical<S,B>, Structure1D.LongIndex, Structure1D.LoopCallback

Field Summary

Fields

Modifier and Type	Field	Description
final int	index	The row index of the original body matrix, [A].
private final BasicArray<?>	myBody	The (nonzero) elements of this equation/row
private double	myPivot
private double	myRHS

Constructor Summary

Constructors

Constructor	Description
Equation(BasicArray<?> body, int pivot, double rhs)

Method Summary

Modifier and Type	Method	Description
void	add(int ind, double addend)
void	add(long ind, Comparable<?> addend)
<T extends Access1D<Double> & Mutate1D.Modifiable<Double>> double	adjust(T x, double relaxation)	Will perform a (relaxed) GaussSeidel update.
private <T extends Access1D<Double> & Mutate1D.Modifiable<Double>> double	calculate(T x, double rhs, double relaxation)
int	compareTo(Equation other)
long	count()	The total number of elements in this structure.
static Equation	dense(int pivot, int cols)
static <N extends Comparable<N>> Equation	dense(int pivot, int cols, DenseArray.Factory<N,?> factory)
static List<Equation>	denseSystem(int rows, int cols)
static <N extends Comparable<N>> List<Equation>	denseSystem(int rows, int cols, DenseArray.Factory<N,?> factory)
double	dot(Access1D<?> vector)	Will calculate and return the dot product of this 1D-structure and another input 1D-vector.
double	dotLower(Access1D<?> x)	Efficiently compute sum_{j invalid input: '<' pivot} a_{ij} * x_j (excludes the pivot).
double	dotUpper(Access1D<?> x)	Efficiently compute sum_{j > pivot} a_{ij} * x_j (excludes the pivot).
double	doubleValue(int ind)
boolean	equals(Object obj)
Double	get(long ind)
BasicArray<?>	getBody()
double[]	getCoefficients()
double	getPivot()
double	getRHS()
int	hashCode()
<T extends Access1D<Double> & Mutate1D.Modifiable<Double>> void	initialise(T x)	Initialises the solution vector's element at index to the value that would solve this equation if the RHS was zero and all other elements in the solution vector unchanged.
void	modifyOne(long ind, UnaryFunction<Double> modifier)
static Equation	of(double rhs, int pivot, double... body)
void	set(long ind, double value)
void	set(long ind, Comparable<?> value)
void	setRHS(double rhs)
int	size()	The total number of elements in this structure.
static Equation	sparse(int pivot, int cols)
static Equation	sparse(int pivot, int cols, int numberOfNonzeros)
static <N extends Comparable<N>> Equation	sparse(int pivot, int cols, PlainArray.Factory<N,?> factory)
static <N extends Comparable<N>> Equation	sparse(int pivot, int cols, PlainArray.Factory<N,?> factory, int numberOfNonzeros)
static List<Equation>	sparseSystem(int rows, int cols)
static List<Equation>	sparseSystem(int rows, int cols, int numberOfNonzeros)
static <N extends Comparable<N>> List<Equation>	sparseSystem(int rows, int cols, PlainArray.Factory<N,?> factory)
static <N extends Comparable<N>> List<Equation>	sparseSystem(int rows, int cols, PlainArray.Factory<N,?> factory, int numberOfNonzeros)
String	toString()
static Equation	wrap(BasicArray<?> body, int pivot, double rhs)

Methods inherited from class Object

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

Methods inherited from interface Access1D

asCollectable1D, asKeyed1D, asList, axpy, byteValue, byteValue, doubleValue, elements, floatValue, floatValue, intValue, intValue, longValue, longValue, nonzeros, select, shortValue, shortValue, supplyTo, toList, toRawCopy1D

Methods inherited from interface Mutate1D.Modifiable

add, add, add, add, add, add, add, add, add, add, add, modifyAll, modifyMatching, modifyMatching, modifyRange

Field Details

index

public final int index

The row index of the original body matrix, [A].

myBody

private final BasicArray<?> myBody

The (nonzero) elements of this equation/row

myPivot

private double myPivot

myRHS

private double myRHS

Constructor Details

Equation

Equation(BasicArray<?> body,
 int pivot,
 double rhs)

Method Details

dense

public static Equation dense(int pivot,
 int cols)

dense

public static <N extends Comparable<N>> Equation dense(int pivot,
 int cols,
 DenseArray.Factory<N,?> factory)

denseSystem

public static List<Equation> denseSystem(int rows,
 int cols)

denseSystem

public static <N extends Comparable<N>>
List<Equation> denseSystem(int rows,
 int cols,
 DenseArray.Factory<N,?> factory)

of

public static Equation of(double rhs,
 int pivot,
 double... body)

sparse

public static Equation sparse(int pivot,
 int cols)

sparse

public static Equation sparse(int pivot,
 int cols,
 int numberOfNonzeros)

sparse

public static <N extends Comparable<N>> Equation sparse(int pivot,
 int cols,
 PlainArray.Factory<N,?> factory)

sparse

public static <N extends Comparable<N>> Equation sparse(int pivot,
 int cols,
 PlainArray.Factory<N,?> factory,
 int numberOfNonzeros)

sparseSystem

public static List<Equation> sparseSystem(int rows,
 int cols)

sparseSystem

public static List<Equation> sparseSystem(int rows,
 int cols,
 int numberOfNonzeros)

sparseSystem

public static <N extends Comparable<N>>
List<Equation> sparseSystem(int rows,
 int cols,
 PlainArray.Factory<N,?> factory)

sparseSystem

public static <N extends Comparable<N>>
List<Equation> sparseSystem(int rows,
 int cols,
 PlainArray.Factory<N,?> factory,
 int numberOfNonzeros)

wrap

public static Equation wrap(BasicArray<?> body,
 int pivot,
 double rhs)

add

public void add(int ind,
 double addend)

Specified by:

add in interface Mutate1D.Modifiable<Double>

add

public void add(long ind,
 Comparable<?> addend)

Specified by:

add in interface Mutate1D.Modifiable<Double>

adjust

public <T extends Access1D<Double> & Mutate1D.Modifiable<Double>>
double adjust(T x,
 double relaxation)

Will perform a (relaxed) GaussSeidel update.

This call will not work if the pivot (the element at index) is zero!

Parameters:

x - The current solution (one element will be updated)

relaxation - Typically 1.0 but could be anything (Most likely should be between 0.0 and 2.0).

Returns:

The error in this equation

compareTo

public int compareTo(Equation other)

Specified by:

compareTo in interface Comparable<Equation>

count

public long count()

Description copied from interface: Structure1D

The total number of elements in this structure.

You only need to implement this method if the structure can contain more than Integer.MAX_VALUE elements.

Specified by:

count in interface Structure1D

dot

public double dot(Access1D<?> vector)

Description copied from interface: Access1D

Will calculate and return the dot product of this 1D-structure and another input 1D-vector.

Specified by:

dot in interface Access1D<Double>

Parameters:

vector - Another 1D-structure

Returns:

The dot product

dotLower

public double dotLower(Access1D<?> x)

Efficiently compute sum_{j invalid input: '<' pivot} a_{ij} * x_j (excludes the pivot). Uses direct sparse iteration when available to avoid O(n) random access scans.

dotUpper

public double dotUpper(Access1D<?> x)

Efficiently compute sum_{j > pivot} a_{ij} * x_j (excludes the pivot). Uses direct sparse iteration when available to avoid O(n) random access scans.

doubleValue

public double doubleValue(int ind)

Specified by:

doubleValue in interface Access1D<Double>

equals

public boolean equals(Object obj)

Overrides:

equals in class Object

get

public Double get(long ind)

Specified by:

get in interface Access1D<Double>

getBody

public BasicArray<?> getBody()

getCoefficients

public double[] getCoefficients()

getPivot

public double getPivot()

Returns:

The element at index

getRHS

public double getRHS()

Returns:

The equation RHS

hashCode

public int hashCode()

Overrides:

hashCode in class Object

initialise

public <T extends Access1D<Double> & Mutate1D.Modifiable<Double>>
void initialise(T x)

Initialises the solution vector's element at index to the value that would solve this equation if the RHS was zero and all other elements in the solution vector unchanged.

Type Parameters:

T - The solution vector type

Parameters:

x - The solution vector to be initialised

modifyOne

public void modifyOne(long ind,
 UnaryFunction<Double> modifier)

Specified by:

modifyOne in interface Mutate1D.Modifiable<Double>

set

public void set(long ind,
 Comparable<?> value)

set

public void set(long ind,
 double value)

setRHS

public void setRHS(double rhs)

size

public int size()

Description copied from interface: Structure1D

The total number of elements in this structure.

Specified by:

size in interface Structure1D

toString

public String toString()

Overrides:

toString in class Object

calculate

private <T extends Access1D<Double> & Mutate1D.Modifiable<Double>>
double calculate(T x,
 double rhs,
 double relaxation)