org.jlinalg

Class LinSysSolver<RE extends IRingElement<?>>

java.lang.Object

org.jlinalg.LinSysSolver<RE>

Type Parameters:

RE - the type for the domain for which equations are to be solved.

All Implemented Interfaces:

java.io.Serializable

public class LinSysSolver<RE extends IRingElement<?>>
extends java.lang.Object
implements java.io.Serializable

This class is capable of solving linear equations.

Author:

Andreas Keilhauer, Georg Thimm

See Also:

Serialized Form

Field Summary

Fields

Modifier and Type	Field and Description
private static long	serialVersionUID

Constructor Summary

Constructors

Constructor and Description
LinSysSolver()

Method Summary

Modifier and Type	Method and Description
static <RE extends IRingElement<RE>> boolean	isSolvable(Matrix<RE> a, Vector<RE> b) Tests whether a linear equation system (A*x=b) is solvable or not.
private static <RE extends IRingElement<RE>> Matrix<RE>	isSolvableHelper(Matrix<RE> a, Vector<RE> b) Does something quite similar to isSolvable but is used by solve and solutionSpace N.B.: In General, this operation will fail, if not all entries are FieldElements.
static <RE extends IRingElement<RE>> AffineLinearSubspace<RE>	solutionSpace(Matrix<RE> a, Vector<RE> b) Calculates the solution space of a given linear equation system of the form A*x=b.
static <RE extends IRingElement<RE>> Vector<RE>	solve(Matrix<RE> a, Vector<RE> b) Calculates a solution of a given linear equation system of the form A*x=b.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

serialVersionUID

private static final long serialVersionUID

See Also:

Constant Field Values

Constructor Detail

LinSysSolver

public LinSysSolver()

Method Detail

solutionSpace

public static <RE extends IRingElement<RE>> AffineLinearSubspace<RE> solutionSpace(Matrix<RE> a,
                                                                                   Vector<RE> b)
                                                                            throws InvalidOperationException

Calculates the solution space of a given linear equation system of the form A*x=b. N.B.: In General, this operation will fail, if not all entries are FieldElements.

Type Parameters:

RE - the type of the dimensions

Parameters:

a - coefficient matrix

b - result vector

Returns:

solution space as an AffinLinearSubSpace.

Throws:

InvalidOperationException - if the matrix and vector sizes mismatch.

solve

public static <RE extends IRingElement<RE>> Vector<RE> solve(Matrix<RE> a,
                                                             Vector<RE> b)

Calculates a solution of a given linear equation system of the form A*x=b. N.B.: In General, this operation will fail, if not all entries are FieldElements.

Type Parameters:

RE - the type of the elements in the matices and vectors.

Parameters:

a - coefficient matrix

b - result vector

Returns:

solution as a Vector.

Throws:

InvalidOperationException - if the matrix and vector sizes mismatch.

isSolvableHelper

private static <RE extends IRingElement<RE>> Matrix<RE> isSolvableHelper(Matrix<RE> a,
                                                                         Vector<RE> b)

Does something quite similar to isSolvable but is used by solve and solutionSpace N.B.: In General, this operation will fail, if not all entries are FieldElements.

Type Parameters:

RE - the type of the coeffcients.

Parameters:

a - coefficient matrix

b - result vector

Returns:

a.gaussjord() without zero rows or null if there is no solution

isSolvable

public static <RE extends IRingElement<RE>> boolean isSolvable(Matrix<RE> a,
                                                               Vector<RE> b)

Tests whether a linear equation system (A*x=b) is solvable or not.

Type Parameters:

RE - the type of the coefficients.

Parameters:

a - coefficient matrix

b - result vector

Returns:

return true if and only if there is a solution for this linear equation system.