Package org.ejml.dense.row.decomposition.svd

Class SafeSvd_DDRM

java.lang.Object

org.ejml.dense.row.decomposition.svd.SafeSvd_DDRM

All Implemented Interfaces:

DecompositionInterface<DMatrixRMaj>, SingularValueDecomposition<DMatrixRMaj>, SingularValueDecomposition_F64<DMatrixRMaj>

public class SafeSvd_DDRM
extends Object
implements SingularValueDecomposition_F64<DMatrixRMaj>

Wraps around a SingularValueDecomposition and ensures that the input is not modified.

Constructor Summary

Constructors

Constructor	Description
SafeSvd_DDRM(SingularValueDecomposition_F64<DMatrixRMaj> alg)

Method Summary

Modifier and Type	Method	Description
boolean	decompose(DMatrixRMaj orig)	Computes the decomposition of the input matrix.
double[]	getSingularValues()	Returns the singular values.
DMatrixRMaj	getU(@Nullable DMatrixRMaj U, boolean transposed)	Returns the orthogonal 'U' matrix.
DMatrixRMaj	getV(@Nullable DMatrixRMaj V, boolean transposed)	Returns the orthogonal 'V' matrix.
DMatrixRMaj	getW(@Nullable DMatrixRMaj W)	Returns a diagonal matrix with the singular values.
boolean	inputModified()	Checks if the input matrix to DecompositionInterface.decompose(org.ejml.data.Matrix) is modified during the decomposition process.
boolean	isCompact()	If true then compact matrices are returned.
int	numberOfSingularValues()	The number of singular values in the matrix.
int	numCols()	Number of columns in the decomposed matrix.
int	numRows()	Number of rows in the decomposed matrix.

Methods inherited from class java.lang.Object

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

Constructor Details

SafeSvd_DDRM

public SafeSvd_DDRM(SingularValueDecomposition_F64<DMatrixRMaj> alg)

Method Details

getSingularValues

public double[] getSingularValues()

Description copied from interface: SingularValueDecomposition_F64

Returns the singular values. This is the diagonal elements of the W matrix in the decomposition. Ordering of singular values is not guaranteed..

Specified by:

getSingularValues in interface SingularValueDecomposition_F64<DMatrixRMaj>

Returns:

Singular values. Note this array can be longer than the number of singular values. Extra elements have no meaning.

numberOfSingularValues

public int numberOfSingularValues()

Description copied from interface: SingularValueDecomposition

The number of singular values in the matrix. This is equal to the length of the smallest side.

Specified by:

numberOfSingularValues in interface SingularValueDecomposition<DMatrixRMaj>

Returns:

Number of singular values in the matrix.

isCompact

public boolean isCompact()

Description copied from interface: SingularValueDecomposition

If true then compact matrices are returned.

Specified by:

isCompact in interface SingularValueDecomposition<DMatrixRMaj>

Returns:

true if results use compact notation.

getU

public DMatrixRMaj getU(@Nullable
 @Nullable DMatrixRMaj U,
 boolean transposed)

Description copied from interface: SingularValueDecomposition

Returns the orthogonal 'U' matrix.

Internally the SVD algorithm might compute U transposed or it might not. To avoid an unnecessary double transpose the option is provided to select if the transpose is returned.

Specified by:

getU in interface SingularValueDecomposition<DMatrixRMaj>

Parameters:

U - Optional storage for U. If null a new instance or internally maintained matrix is returned. Modified.

transposed - If the returned U is transposed.

Returns:

An orthogonal matrix.

getV

public DMatrixRMaj getV(@Nullable
 @Nullable DMatrixRMaj V,
 boolean transposed)

Description copied from interface: SingularValueDecomposition

Returns the orthogonal 'V' matrix.

Internally the SVD algorithm might compute V transposed or it might not. To avoid an unnecessary double transpose the option is provided to select if the transpose is returned.

Specified by:

getV in interface SingularValueDecomposition<DMatrixRMaj>

Parameters:

V - Optional storage for v. If null a new instance or internally maintained matrix is returned. Modified.

transposed - If the returned V is transposed.

Returns:

An orthogonal matrix.

getW

public DMatrixRMaj getW(@Nullable
 @Nullable DMatrixRMaj W)

Description copied from interface: SingularValueDecomposition

Returns a diagonal matrix with the singular values. Order of the singular values is not guaranteed.

Specified by:

getW in interface SingularValueDecomposition<DMatrixRMaj>

Parameters:

W - Optional storage for W. If null a new instance or internally maintained matrix is returned. Modified.

Returns:

Diagonal matrix with singular values along the diagonal.

numRows

public int numRows()

Description copied from interface: SingularValueDecomposition

Number of rows in the decomposed matrix.

Specified by:

numRows in interface SingularValueDecomposition<DMatrixRMaj>

Returns:

Number of rows in the decomposed matrix.

numCols

public int numCols()

Description copied from interface: SingularValueDecomposition

Number of columns in the decomposed matrix.

Specified by:

numCols in interface SingularValueDecomposition<DMatrixRMaj>

Returns:

Number of columns in the decomposed matrix.

decompose

public boolean decompose(DMatrixRMaj 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<DMatrixRMaj>

Parameters:

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

Returns:

Returns if it was able to decompose the matrix.

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<DMatrixRMaj>

Returns:

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