Package org.apache.commons.math.linear
Interface FieldLUDecomposition<T extends FieldElement<T>>
-
- Type Parameters:
T
- the type of the field elements
- All Known Implementing Classes:
FieldLUDecompositionImpl
public interface FieldLUDecomposition<T extends FieldElement<T>>
An interface to classes that implement an algorithm to calculate the LU-decomposition of a real matrix.The LU-decomposition of matrix A is a set of three matrices: P, L and U such that P×A = L×U. P is a rows permutation matrix that is used to rearrange the rows of A before so that it can be decomposed. L is a lower triangular matrix with unit diagonal terms and U is an upper triangular matrix.
This interface is based on the class with similar name from the JAMA library.
- a
getP
method has been added, - the
det
method has been renamed asgetDeterminant
, - the
getDoublePivot
method has been removed (but the int basedgetPivot
method has been kept), - the
solve
andisNonSingular
methods have been replaced by agetSolver
method and the equivalent methods provided by the returnedDecompositionSolver
.
-
-
Method Summary
All Methods Instance Methods Abstract Methods Modifier and Type Method Description T
getDeterminant()
Return the determinant of the matrixFieldMatrix<T>
getL()
Returns the matrix L of the decomposition.FieldMatrix<T>
getP()
Returns the P rows permutation matrix.int[]
getPivot()
Returns the pivot permutation vector.FieldDecompositionSolver<T>
getSolver()
Get a solver for finding the A × X = B solution in exact linear sense.FieldMatrix<T>
getU()
Returns the matrix U of the decomposition.
-
-
-
Method Detail
-
getL
FieldMatrix<T> getL()
Returns the matrix L of the decomposition.L is an lower-triangular matrix
- Returns:
- the L matrix (or null if decomposed matrix is singular)
-
getU
FieldMatrix<T> getU()
Returns the matrix U of the decomposition.U is an upper-triangular matrix
- Returns:
- the U matrix (or null if decomposed matrix is singular)
-
getP
FieldMatrix<T> getP()
Returns the P rows permutation matrix.P is a sparse matrix with exactly one element set to 1.0 in each row and each column, all other elements being set to 0.0.
The positions of the 1 elements are given by the
pivot permutation vector
.- Returns:
- the P rows permutation matrix (or null if decomposed matrix is singular)
- See Also:
getPivot()
-
getPivot
int[] getPivot()
Returns the pivot permutation vector.- Returns:
- the pivot permutation vector
- See Also:
getP()
-
getDeterminant
T getDeterminant()
Return the determinant of the matrix- Returns:
- determinant of the matrix
-
getSolver
FieldDecompositionSolver<T> getSolver()
Get a solver for finding the A × X = B solution in exact linear sense.- Returns:
- a solver
-
-