Class LinearSolverSafe<T extends ReshapeMatrix>
 All Implemented Interfaces:
LinearSolver<T,T>
,LinearSolverDense<T>
public class LinearSolverSafe<T extends ReshapeMatrix> extends Object implements LinearSolverDense<T>

Constructor Summary
Constructors Constructor Description LinearSolverSafe(LinearSolverDense<T> alg)

Method Summary
Modifier and Type Method Description <D extends DecompositionInterface>
DgetDecomposition()
If a decomposition class was used internally then this will return that class.void
invert(T A_inv)
Computes the inverse of of the 'A' matrix passed intoLinearSolver.setA(Matrix)
and writes the results to the provided matrix.boolean
modifiesA()
Returns true if the passed in matrix toLinearSolver.setA(Matrix)
is modified.boolean
modifiesB()
Returns true if the passed in 'B' matrix toLinearSolver.solve(Matrix, Matrix)
is modified.double
quality()
Returns a very quick to compute measure of how singular the system is.boolean
setA(T A)
Specifies the A matrix in the linear equation.void
solve(T B, T X)
Solves for X in the linear system, A*X=B.

Constructor Details

LinearSolverSafe
 Parameters:
alg
 The solver it is wrapped around.


Method Details

setA
Description copied from interface:LinearSolver
Specifies the A matrix in the linear equation. A reference might be saved and it might also be modified depending on the implementation. If it is modified then
LinearSolver.modifiesA()
will return true.If this value returns true that does not guarantee a valid solution was generated. This is because some decompositions don't detect singular matrices.
 Specified by:
setA
in interfaceLinearSolver<T extends ReshapeMatrix,T extends ReshapeMatrix>
 Parameters:
A
 The 'A' matrix in the linear equation. Might be modified or save the reference. Returns:
 true if it can be processed.

quality
public double quality()Description copied from interface:LinearSolver
Returns a very quick to compute measure of how singular the system is. This measure will be invariant to the scale of the matrix and always be positive, with larger values indicating it is less singular. If not supported by the solver then the runtime exception IllegalArgumentException is thrown. This is NOT the matrix's condition.
How this function is implemented is not specified. One possible implementation is the following: In many decompositions a triangular matrix is extracted. The determinant of a triangular matrix is easily computed and once normalized to be scale invariant and its absolute value taken it will provide functionality described above.
 Specified by:
quality
in interfaceLinearSolver<T extends ReshapeMatrix,T extends ReshapeMatrix>
 Returns:
 The quality of the linear system.

solve
Description copied from interface:LinearSolver
Solves for X in the linear system, A*X=B.
In some implementations 'B' and 'X' can be the same instance of a variable. Call
LinearSolver.modifiesB()
to determine if 'B' is modified. Specified by:
solve
in interfaceLinearSolver<T extends ReshapeMatrix,T extends ReshapeMatrix>
 Parameters:
B
 A matrix ℜ ^{m × p}. Might be modified.X
 A matrix ℜ ^{n × p}, where the solution is written to. Modified.

invert
Description copied from interface:LinearSolverDense
Computes the inverse of of the 'A' matrix passed intoLinearSolver.setA(Matrix)
and writes the results to the provided matrix. If 'A_inv' needs to be different from 'A' is implementation dependent. Specified by:
invert
in interfaceLinearSolverDense<T extends ReshapeMatrix>
 Parameters:
A_inv
 Where the inverted matrix saved. Modified.

modifiesA
public boolean modifiesA()Description copied from interface:LinearSolver
Returns true if the passed in matrix toLinearSolver.setA(Matrix)
is modified. Specified by:
modifiesA
in interfaceLinearSolver<T extends ReshapeMatrix,T extends ReshapeMatrix>
 Returns:
 true if A is modified in setA().

modifiesB
public boolean modifiesB()Description copied from interface:LinearSolver
Returns true if the passed in 'B' matrix toLinearSolver.solve(Matrix, Matrix)
is modified. Specified by:
modifiesB
in interfaceLinearSolver<T extends ReshapeMatrix,T extends ReshapeMatrix>
 Returns:
 true if B is modified in solve(B,X).

getDecomposition
Description copied from interface:LinearSolver
If a decomposition class was used internally then this will return that class. Most linear solvers decompose the input matrix into a more simplistic form. However some solutions do not require decomposition, e.g. inverse by minor. Specified by:
getDecomposition
in interfaceLinearSolver<T extends ReshapeMatrix,T extends ReshapeMatrix>
 Type Parameters:
D
 Decomposition type Returns:
 Internal decomposition class. If there is none then null.
