Class FieldLUDecomposition<T>
- java.lang.Object
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- org.apache.commons.math4.legacy.field.linalg.FieldLUDecomposition<T>
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- Type Parameters:
T- Type of the field elements.
public final class FieldLUDecomposition<T> extends Object
Calculates the LUP-decomposition of a square matrix.The LUP-decomposition of a matrix A consists of three matrices L, U and P that satisfy: PA = LU, L is lower triangular, and U is upper triangular and P is a permutation matrix. All matrices are m×m.
Since
fieldelements do not provide an ordering operator, the permutation matrix is computed here only in order to avoid a zero pivot element, no attempt is done to get the largest pivot element.
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Method Summary
All Methods Static Methods Instance Methods Concrete Methods Modifier and Type Method Description TgetDeterminant()Return the determinant of the matrix.FieldDenseMatrix<T>getL()Builds the "L" matrix of the decomposition.FieldDenseMatrix<T>getP()Builds the "P" matrix.int[]getPivot()Gets the pivot permutation vector.FieldDecompositionSolver<T>getSolver()Creates a solver for finding the solutionXof the linear system of equationsA X = B.FieldDenseMatrix<T>getU()Builds the "U" matrix of the decomposition.booleanisSingular()static <T> FieldLUDecomposition<T>of(FieldDenseMatrix<T> m)Factory method.
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Method Detail
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of
public static <T> FieldLUDecomposition<T> of(FieldDenseMatrix<T> m)
Factory method.- Type Parameters:
T- Type of the field elements.- Parameters:
m- Matrix to decompose.- Returns:
- a new instance.
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isSingular
public boolean isSingular()
- Returns:
trueif the matrix is singular.
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getL
public FieldDenseMatrix<T> getL()
Builds the "L" matrix of the decomposition.- Returns:
- the lower triangular matrix.
- Throws:
SingularMatrixException- if the matrix is singular.
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getU
public FieldDenseMatrix<T> getU()
Builds the "U" matrix of the decomposition.- Returns:
- the upper triangular matrix.
- Throws:
SingularMatrixException- if the matrix is singular.
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getP
public FieldDenseMatrix<T> getP()
Builds the "P" matrix.P is a matrix with exactly one element set to
onein each row and each column, all other elements being set tozero. The positions of the "one" elements are given by thepivot permutation vector.- Returns:
- the "P" rows permutation matrix.
- Throws:
SingularMatrixException- if the matrix is singular.- See Also:
getPivot()
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getPivot
public int[] getPivot()
Gets the pivot permutation vector.- Returns:
- the pivot permutation vector.
- See Also:
getP()
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getDeterminant
public T getDeterminant()
Return the determinant of the matrix.- Returns:
- determinant of the matrix
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getSolver
public FieldDecompositionSolver<T> getSolver()
Creates a solver for finding the solutionXof the linear system of equationsA X = B.- Returns:
- a solver.
- Throws:
SingularMatrixException- if the matrix is singular.
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