Package org.ejml.sparse.csc.decomposition.chol

Class CholeskyUpLooking_DSCC

java.lang.Object

org.ejml.sparse.csc.decomposition.chol.CholeskyUpLooking_DSCC

All Implemented Interfaces:

CholeskyDecomposition<DMatrixSparseCSC>, CholeskySparseDecomposition<DMatrixSparseCSC>, CholeskySparseDecomposition_F64<DMatrixSparseCSC>, DecompositionInterface<DMatrixSparseCSC>, DecompositionSparseInterface<DMatrixSparseCSC>

public class CholeskyUpLooking_DSCC
extends Object
implements CholeskySparseDecomposition_F64<DMatrixSparseCSC>

Performs a Cholesky decomposition using an up looking algorthm on a DMatrixSparseCSC.

See page 59 in "Direct Methods for Sparse Linear Systems" by Tomothy A. Davis

Constructor Summary

Constructors

Constructor	Description
CholeskyUpLooking_DSCC()

Method Summary

Modifier and Type	Method	Description
Complex_F64	computeDeterminant()	Computes the matrix's determinant using the decomposition.
boolean	decompose(DMatrixSparseCSC orig)	Computes the decomposition of the input matrix.
IGrowArray	getGw()
DGrowArray	getGx()
DMatrixSparseCSC	getL()
DMatrixSparseCSC	getT(@Nullable DMatrixSparseCSC T)	Returns the triangular matrix from the decomposition.
boolean	inputModified()	Checks if the input matrix to DecompositionInterface.decompose(org.ejml.data.Matrix) is modified during the decomposition process.
boolean	isLower()	If true the decomposition was for a lower triangular matrix.
boolean	isStructureLocked()	Checks to see if the structure is locked.
void	performSymbolic(DMatrixSparseCSC A)
void	setStructureLocked(boolean locked)	Save results from structural analysis step.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Details

CholeskyUpLooking_DSCC

public CholeskyUpLooking_DSCC()

Method Details

decompose

public boolean decompose(DMatrixSparseCSC orig)

Description copied from interface: DecompositionInterface

Computes the decomposition of the input matrix. Depending on the implementation the input matrix might be stored internally or modified. If it is modified then the function DecompositionInterface.inputModified() will return true and the matrix should not be modified until the decomposition is no longer needed.

Specified by:

decompose in interface DecompositionInterface<DMatrixSparseCSC>

Parameters:

orig - The matrix which is being decomposed. Modification is implementation dependent.

Returns:

Returns if it was able to decompose the matrix.

performSymbolic

public void performSymbolic(DMatrixSparseCSC A)

inputModified

public boolean inputModified()

Description copied from interface: DecompositionInterface

Checks if the input matrix to DecompositionInterface.decompose(org.ejml.data.Matrix) is modified during the decomposition process.

Specified by:

inputModified in interface DecompositionInterface<DMatrixSparseCSC>

Returns:

true if the input matrix to decompose() is modified.

isLower

public boolean isLower()

Description copied from interface: CholeskyDecomposition

If true the decomposition was for a lower triangular matrix. If false it was for an upper triangular matrix.

Specified by:

isLower in interface CholeskyDecomposition<DMatrixSparseCSC>

Returns:

True if lower, false if upper.

getT

public DMatrixSparseCSC getT(@Nullable
 @Nullable DMatrixSparseCSC T)

Description copied from interface: CholeskyDecomposition

Returns the triangular matrix from the decomposition.

If an input is provided that matrix is used to write the results to. Otherwise a new matrix is created and the results written to it.

Specified by:

getT in interface CholeskyDecomposition<DMatrixSparseCSC>

Parameters:

T - If not null then the decomposed matrix is written here.

Returns:

A lower or upper triangular matrix.

computeDeterminant

public Complex_F64 computeDeterminant()

Description copied from interface: CholeskySparseDecomposition_F64

Computes the matrix's determinant using the decomposition.

Specified by:

computeDeterminant in interface CholeskySparseDecomposition_F64<DMatrixSparseCSC>

Returns:

The determinant.

getGx

public DGrowArray getGx()

getL

public DMatrixSparseCSC getL()

getGw

public IGrowArray getGw()

setStructureLocked

public void setStructureLocked(boolean locked)

Description copied from interface: DecompositionSparseInterface

Save results from structural analysis step. This can reduce computations if 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:

setStructureLocked in interface DecompositionSparseInterface<DMatrixSparseCSC>

isStructureLocked

public boolean isStructureLocked()

Description copied from interface: DecompositionSparseInterface

Checks to see if the structure is locked.

Specified by:

isStructureLocked in interface DecompositionSparseInterface<DMatrixSparseCSC>

Returns:

true if locked or false if not locked.