## org.apache.commons.math.linear
Class LUDecompositionImpl.Solver

    java.lang.Object
      org.apache.commons.math.linear.LUDecompositionImpl.Solver

All Implemented Interfaces:
  DecompositionSolver

Enclosing class:
  LUDecompositionImpl

    private static class LUDecompositionImpl.Solver

extends Object
implements DecompositionSolver

Specialized solver.

Field Summary
`private double[][]` `lu` Entries of LU decomposition.
`private int[]` `pivot` Pivot permutation associated with LU decomposition.
`private boolean` `singular` Singularity indicator.

Constructor Summary
`private` `LUDecompositionImpl.Solver(double[][] lu, int[] pivot, boolean singular)` Build a solver from decomposed matrix.

Method Summary
`RealMatrix` `getInverse()` Get the inverse (or pseudo-inverse) of the decomposed matrix.
`boolean` `isNonSingular()` Check if the decomposed matrix is non-singular.
`ArrayRealVector` `solve(ArrayRealVector b)` Solve the linear equation A × X = B.
`double[]` `solve(double[] b)` Solve the linear equation A × X = B for matrices A.
`RealMatrix` `solve(RealMatrix b)` Solve the linear equation A × X = B for matrices A.
`RealVector` `solve(RealVector b)` Solve the linear equation A × X = B for matrices A.

Methods inherited from class java.lang.Object
`clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait`

Field Detail

### lu

    private final double[][] lu

  Entries of LU decomposition.

### pivot

    private final int[] pivot

  Pivot permutation associated with LU decomposition.

### singular

    private final boolean singular

  Singularity indicator.

Constructor Detail

### LUDecompositionImpl.Solver

    private LUDecompositionImpl.Solver(double[][] lu,
                                       int[] pivot,
                                       boolean singular)

  Build a solver from decomposed matrix.

  Parameters:
    `lu` - entries of LU decomposition
    `pivot` - pivot permutation associated with LU decomposition
    `singular` - singularity indicator

Method Detail

### isNonSingular

    public boolean isNonSingular()

  Check if the decomposed matrix is non-singular.

  Specified by:
    `isNonSingular` in interface `DecompositionSolver`
  Returns:
    true if the decomposed matrix is non-singular

### solve

    public double[] solve(double[] b)
                   throws IllegalArgumentException,
                          InvalidMatrixException

  Solve the linear equation A × X = B for matrices A.

  The A matrix is implicit, it is provided by the underlying decomposition algorithm.

  Specified by:
    `solve` in interface `DecompositionSolver`
  Parameters:
    `b` - right-hand side of the equation A × X = B
  Returns:
    a vector X that minimizes the two norm of A × X - B
  Throws:
    `IllegalArgumentException` - if matrices dimensions don't match
    `InvalidMatrixException` - if decomposed matrix is singular

### solve

    public RealVector solve(RealVector b)
                     throws IllegalArgumentException,
                            InvalidMatrixException

  Solve the linear equation A × X = B for matrices A.

  The A matrix is implicit, it is provided by the underlying decomposition algorithm.

  Specified by:
    `solve` in interface `DecompositionSolver`
  Parameters:
    `b` - right-hand side of the equation A × X = B
  Returns:
    a vector X that minimizes the two norm of A × X - B
  Throws:
    `IllegalArgumentException` - if matrices dimensions don't match
    `InvalidMatrixException` - if decomposed matrix is singular

### solve

    public ArrayRealVector solve(ArrayRealVector b)
                          throws IllegalArgumentException,
                                 InvalidMatrixException

  Solve the linear equation A × X = B.

  The A matrix is implicit here. It is

  Parameters:
    `b` - right-hand side of the equation A × X = B
  Returns:
    a vector X such that A × X = B
  Throws:
    `IllegalArgumentException` - if matrices dimensions don't match
    `InvalidMatrixException` - if decomposed matrix is singular

### solve

    public RealMatrix solve(RealMatrix b)
                     throws IllegalArgumentException,
                            InvalidMatrixException

  Solve the linear equation A × X = B for matrices A.

  The A matrix is implicit, it is provided by the underlying decomposition algorithm.

  Specified by:
    `solve` in interface `DecompositionSolver`
  Parameters:
    `b` - right-hand side of the equation A × X = B
  Returns:
    a matrix X that minimizes the two norm of A × X - B
  Throws:
    `IllegalArgumentException` - if matrices dimensions don't match
    `InvalidMatrixException` - if decomposed matrix is singular

### getInverse

    public RealMatrix getInverse()
                          throws InvalidMatrixException

  Get the inverse (or pseudo-inverse) of the decomposed matrix.

  Specified by:
    `getInverse` in interface `DecompositionSolver`
  Returns:
    inverse matrix
  Throws:
    `InvalidMatrixException` - if decomposed matrix is singular

Copyright (c) 2003-2013 Apache Software Foundation