public interface LinearSolver<S extends Matrix,D extends Matrix>
Base class for Linear Solvers.
LinearSolverDense
Modifier and Type | Method and Description |
---|---|
<D extends DecompositionInterface> |
getDecomposition()
If a decomposition class was used internally then this will return that class.
|
boolean |
modifiesA()
Returns true if the passed in matrix to
setA(Matrix)
is modified. |
boolean |
modifiesB()
Returns true if the passed in 'B' matrix to
solve(Matrix, Matrix)
is modified. |
double |
quality()
Returns a very quick to compute measure of how singular the system is.
|
boolean |
setA(S A)
Specifies the A matrix in the linear equation.
|
void |
solve(D B,
D X)
Solves for X in the linear system, A*X=B.
|
boolean setA(S A)
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 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.
A
- The 'A' matrix in the linear equation. Might be modified or save the reference.double quality()
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.
void solve(D B, D X)
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
modifiesB()
to determine if 'B' is modified.
B
- A matrix ℜ m × p. Might be modified.X
- A matrix ℜ n × p, where the solution is written to. Modified.boolean modifiesA()
setA(Matrix)
is modified.boolean modifiesB()
solve(Matrix, Matrix)
is modified.<D extends DecompositionInterface> D getDecomposition()
D
- Decomposition type