Class LinearSolverSparseSafe<S extends DMatrixSparse,D extends ReshapeMatrix>
- java.lang.Object
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- org.ejml.LinearSolverSparseSafe<S,D>
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- All Implemented Interfaces:
LinearSolver<S,D>,LinearSolverSparse<S,D>
public class LinearSolverSparseSafe<S extends DMatrixSparse,D extends ReshapeMatrix> extends java.lang.Object implements LinearSolverSparse<S,D>
Ensures that any linear solver it is wrapped around will never modify the input matrices.
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Constructor Summary
Constructors Constructor Description LinearSolverSparseSafe(LinearSolverSparse<S,D> alg)
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Method Summary
All Methods Instance Methods Concrete Methods Modifier and Type Method Description <D extends DecompositionInterface>
DgetDecomposition()If a decomposition class was used internally then this will return that class.booleanisStructureLocked()Checks to see if the structure is locked.booleanmodifiesA()Returns true if the passed in matrix toLinearSolver.setA(Matrix)is modified.booleanmodifiesB()Returns true if the passed in 'B' matrix toLinearSolver.solve(Matrix, Matrix)is modified.doublequality()Returns a very quick to compute measure of how singular the system is.booleansetA(S A)Specifies the A matrix in the linear equation.voidsetStructureLocked(boolean locked)Save results from structural analysis step.voidsolve(D B, D X)Solves for X in the linear system, A*X=B.voidsolveSparse(S B, S X)Solve against sparse matrices.
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Constructor Detail
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LinearSolverSparseSafe
public LinearSolverSparseSafe(LinearSolverSparse<S,D> alg)
- Parameters:
alg- The solver it is wrapped around.
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Method Detail
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setA
public boolean setA(S A)
Description copied from interface:LinearSolverSpecifies 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:
setAin interfaceLinearSolver<S extends DMatrixSparse,D 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.
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quality
public double quality()
Description copied from interface:LinearSolverReturns 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:
qualityin interfaceLinearSolver<S extends DMatrixSparse,D extends ReshapeMatrix>- Returns:
- The quality of the linear system.
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solve
public void solve(D B, D X)
Description copied from interface:LinearSolverSolves 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:
solvein interfaceLinearSolver<S extends DMatrixSparse,D 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.
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modifiesA
public boolean modifiesA()
Description copied from interface:LinearSolverReturns true if the passed in matrix toLinearSolver.setA(Matrix)is modified.- Specified by:
modifiesAin interfaceLinearSolver<S extends DMatrixSparse,D extends ReshapeMatrix>- Returns:
- true if A is modified in setA().
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modifiesB
public boolean modifiesB()
Description copied from interface:LinearSolverReturns true if the passed in 'B' matrix toLinearSolver.solve(Matrix, Matrix)is modified.- Specified by:
modifiesBin interfaceLinearSolver<S extends DMatrixSparse,D extends ReshapeMatrix>- Returns:
- true if B is modified in solve(B,X).
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getDecomposition
public <D extends DecompositionInterface> D getDecomposition()
Description copied from interface:LinearSolverIf 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:
getDecompositionin interfaceLinearSolver<S extends DMatrixSparse,D extends ReshapeMatrix>- Type Parameters:
D- Decomposition type- Returns:
- Internal decomposition class. If there is none then null.
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solveSparse
public void solveSparse(S B, S X)
Description copied from interface:LinearSolverSparseSolve against sparse matrices. A*X=B. In most situations its more desirable to solve against a dense matrix because of fill in.- Specified by:
solveSparsein interfaceLinearSolverSparse<S extends DMatrixSparse,D extends ReshapeMatrix>- Parameters:
B- Input. Never modified.X- Output. Never modified.
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setStructureLocked
public void setStructureLocked(boolean locked)
Description copied from interface:LinearSolverSparseSave results from structural analysis step. This can reduce computations of a matrix with the exactly same non-zero pattern is decomposed in the future. If a matrix has yet to be processed then the structure of the next matrix is saved. If a matrix has already been processed then the structure of the most recently processed matrix will be saved.
- Specified by:
setStructureLockedin interfaceLinearSolverSparse<S extends DMatrixSparse,D extends ReshapeMatrix>
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isStructureLocked
public boolean isStructureLocked()
Description copied from interface:LinearSolverSparseChecks to see if the structure is locked.- Specified by:
isStructureLockedin interfaceLinearSolverSparse<S extends DMatrixSparse,D extends ReshapeMatrix>- Returns:
- true if locked or false if not locked.
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