fr.cnes.sirius.patrius.math.linear

Class ArrayRowSymmetricMatrix

java.lang.Object

fr.cnes.sirius.patrius.math.linear.RealLinearOperator

fr.cnes.sirius.patrius.math.linear.AbstractRealMatrix

fr.cnes.sirius.patrius.math.linear.ArrayRowSymmetricMatrix

All Implemented Interfaces:

AnyMatrix, RealMatrix, SymmetricMatrix, Serializable

public class ArrayRowSymmetricMatrix
extends AbstractRealMatrix
implements SymmetricMatrix, Serializable

Symmetric matrix defined by its lower triangular part.

This implementation stores the elements of the lower triangular part of a symmetric matrix. These elements are stored in a 1D array, row after row. For example, for a 3 by 3 matrix we have:
(1) = s_1,1;
(2) = s_2,1; (3) = s_2,2;
(4) = s_3,1; (5) = s_3,2; (6) = s_3,3;

The elements actually stored depends on the type of symmetry specified at construction: LOWER or UPPER implies the symmetry is enforced by keeping only the lower or upper triangular part of the matrix, while MEAN enforces the symmetry by computing the mean of the lower and upper elements. The symmetry the provided matrix is not checked by default, meaning that the symmetry is enforced regardless of the inputs. However, such a check can be triggered by setting the default absolute and relative symmetry thresholds to a non-null value or by providing these thresholds at construction.

Important:
Because only half the elements of the matrix are actually stored, setting an off-diagonal element to a new value will automatically modify the symmetric element. As a result, the symmetry of the matrix will automatically be preserved. However, note that the method setSubMatrix is not supported and will systematically throw a MathUnsupportedOperationException.

Since:

4.5 (was previously called SymmetricMatrix, which now describes the interface)

Author:

GMV

See Also:

Serialized Form

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	ArrayRowSymmetricMatrix.SymmetryType Enumerate to fill in a symmetric matrix only by its lower/upper part.

Constructor Summary

Constructors

Modifier	Constructor and Description
	ArrayRowSymmetricMatrix(ArrayRowSymmetricMatrix.SymmetryType symmetryType, double[][] dataIn) Builds a new ArrayRowSymmetricMatrix from the provided data, using the default symmetry thresholds.
	ArrayRowSymmetricMatrix(ArrayRowSymmetricMatrix.SymmetryType symmetryType, double[][] dataIn, Double absoluteSymmetryThreshold, Double relativeSymmetryThreshold) Builds a new ArrayRowSymmetricMatrix from the provided data, using the specified symmetry thresholds.
	ArrayRowSymmetricMatrix(ArrayRowSymmetricMatrix.SymmetryType symmetryType, RealMatrix matrix) Builds a new ArrayRowSymmetricMatrix from the provided matrix, using the default symmetry thresholds.
	ArrayRowSymmetricMatrix(ArrayRowSymmetricMatrix.SymmetryType symmetryType, RealMatrix matrix, Double absoluteSymmetryThreshold, Double relativeSymmetryThreshold) Builds a new ArrayRowSymmetricMatrix from the provided matrix, using the specified symmetry thresholds.
protected	ArrayRowSymmetricMatrix(double[] dataIn, boolean copyArray) Builds a new ArrayRowSymmetricMatrix by specifying the lower triangular part of the matrix directly.
	ArrayRowSymmetricMatrix(int n) Builds a new ArrayRowSymmetricMatrix of dimension n (filled with zero).

Method Summary

Modifier and Type	Method and Description
ArrayRowSymmetricMatrix	add(DiagonalMatrix m) Compute the sum of this and m.
RealMatrix	add(RealMatrix m) Returns the sum of this and m.
ArrayRowSymmetricMatrix	add(SymmetricMatrix m) Adds a SymmetricMatrix to this matrix.
void	addToEntry(int row, int column, double increment) Adds (in place) the specified value to the specified entry of this matrix.
ArrayRowSymmetricMatrix	copy() Returns a (deep) copy of this.
ArrayRowSymmetricMatrix	createMatrix(int rowDimension, int columnDimension) Create a new RealMatrix of the same type as the instance with the supplied row and column dimensions.
int	getColumnDimension() Returns the number of columns of this matrix.
RealMatrix	getColumnMatrix(int column) Get the entries at the given column index as a column matrix.
static Double	getDefaultAbsoluteSymmetryThreshold() Gets the default absolute threshold above which off-diagonal elements are considered different.
static Double	getDefaultRelativeSymmetryThreshold() Gets the default relative threshold above which off-diagonal elements are considered different.
double	getEntry(int row, int column) Get the entry in the specified row and column.
protected double[]	getInternalData() Gets the internal array storing the lower part of the symmetric matrix.
ArrayRowSymmetricMatrix	getInverse() Get the inverse (or pseudo-inverse) of the decomposed matrix.
ArrayRowSymmetricMatrix	getInverse(Decomposition decomposition) Get the inverse (or pseudo-inverse) matrix computed with the given decomposition algorithm.
int	getRowDimension() Returns the number of rows of this matrix.
RealMatrix	getRowMatrix(int row) Get the entries at the given row index as a row matrix.
RealMatrix	getSubMatrix(int[] selectedRows, int[] selectedColumns) Gets a submatrix.
RealMatrix	getSubMatrix(int startRow, int endRow, int startColumn, int endColumn) Gets a submatrix.
void	multiplyEntry(int row, int column, double factor) Multiplies (in place) the specified entry of this matrix by the specified value.
ArrayRowSymmetricMatrix	permutation(int[] index) Permute the rows/columns of this matrix according to a new specified index order list.
ArrayRowSymmetricMatrix	power(int p) Returns the result of multiplying this with itself p times.
ArrayRowSymmetricMatrix	quadraticMultiplication(RealMatrix m) Gets the result of the quadratic multiplication M×S×MT, where S is this matrix and M is the provided matrix.
ArrayRowSymmetricMatrix	quadraticMultiplication(RealMatrix m, boolean isTranspose) Gets the result of the quadratic multiplication M×S×MT, where S is this matrix and M or MT is the provided matrix.
ArrayRowSymmetricMatrix	scalarAdd(double d) Returns the result of adding d to each entry of this.
ArrayRowSymmetricMatrix	scalarMultiply(double d) Returns the result of multiplying each entry of this by d.
static void	setDefaultAbsoluteSymmetryThreshold(Double threshold) Sets the default absolute threshold above which off-diagonal elements are considered different.
static void	setDefaultRelativeSymmetryThreshold(Double threshold) Sets the default relative threshold above which off-diagonal elements are considered different.
void	setEntry(int row, int column, double value) Set the entry in the specified row and column.
void	setSubMatrix(double[][] subMatrix, int row, int column) The method systematically throws a MathUnsupportedOperationException as this operation is not safe when we deal with a SymmetricMatrix.
void	setSubMatrix(RealMatrix subMatrix, int row, int column) Method setSubMatrix using a RealMatrix for subMatrix instead of an array
ArrayRowSymmetricMatrix	subtract(DiagonalMatrix m) Compute this minus m.
RealMatrix	subtract(RealMatrix m) Returns this minus m.
ArrayRowSymmetricMatrix	subtract(SymmetricMatrix m) Subtracts a SymmetricMatrix from this matrix.
ArrayRowSymmetricMatrix	transpose() Returns the transpose of this matrix.

Methods inherited from class fr.cnes.sirius.patrius.math.linear.AbstractRealMatrix

concatenateDiagonally, concatenateHorizontally, concatenateVertically, copySubMatrix, copySubMatrix, equals, equals, getColumn, getColumnVector, getData, getDefaultDecomposition, getFrobeniusNorm, getNorm, getRow, getRowVector, getTrace, hashCode, isAntisymmetric, isDiagonal, isInvertible, isOrthogonal, isSquare, isSymmetric, isSymmetric, isSymmetric, multiply, multiply, multiply, multiply, operate, operate, preMultiply, preMultiply, preMultiply, setColumn, setColumnMatrix, setColumnVector, setDefaultDecomposition, setRow, setRowMatrix, setRowVector, toString, toString, walkInColumnOrder, walkInColumnOrder, walkInColumnOrder, walkInColumnOrder, walkInOptimizedOrder, walkInOptimizedOrder, walkInOptimizedOrder, walkInOptimizedOrder, walkInRowOrder, walkInRowOrder, walkInRowOrder, walkInRowOrder

Methods inherited from class fr.cnes.sirius.patrius.math.linear.RealLinearOperator

isTransposable, operateTranspose

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface fr.cnes.sirius.patrius.math.linear.RealMatrix

concatenateDiagonally, concatenateHorizontally, concatenateVertically, copySubMatrix, copySubMatrix, equals, getColumn, getColumnVector, getData, getDefaultDecomposition, getFrobeniusNorm, getNorm, getRow, getRowVector, getTrace, isAntisymmetric, isDiagonal, isInvertible, isOrthogonal, isSymmetric, isSymmetric, isSymmetric, multiply, multiply, multiply, operate, operate, preMultiply, preMultiply, preMultiply, setColumn, setColumnMatrix, setColumnVector, setDefaultDecomposition, setRow, setRowMatrix, setRowVector, toString, walkInColumnOrder, walkInColumnOrder, walkInColumnOrder, walkInColumnOrder, walkInOptimizedOrder, walkInOptimizedOrder, walkInOptimizedOrder, walkInOptimizedOrder, walkInRowOrder, walkInRowOrder, walkInRowOrder, walkInRowOrder

Methods inherited from interface fr.cnes.sirius.patrius.math.linear.AnyMatrix

isSquare

Constructor Detail

ArrayRowSymmetricMatrix

public ArrayRowSymmetricMatrix(int n)

Builds a new ArrayRowSymmetricMatrix of dimension n (filled with zero).

Parameters:

n - the dimension of the matrix

ArrayRowSymmetricMatrix

public ArrayRowSymmetricMatrix(ArrayRowSymmetricMatrix.SymmetryType symmetryType,
                               double[][] dataIn)

Builds a new ArrayRowSymmetricMatrix from the provided data, using the default symmetry thresholds.

Parameters:

symmetryType - the type of symmetry enforced at construction

dataIn - the data of the matrix (must be a NxN array)

Throws:

NonSquareMatrixException - if the provided matrix is not square (unchecked)

NonSymmetricMatrixException - if the provided matrix is not symmetric (unchecked)

See Also:

getDefaultRelativeSymmetryThreshold()

ArrayRowSymmetricMatrix

public ArrayRowSymmetricMatrix(ArrayRowSymmetricMatrix.SymmetryType symmetryType,
                               double[][] dataIn,
                               Double absoluteSymmetryThreshold,
                               Double relativeSymmetryThreshold)

Builds a new ArrayRowSymmetricMatrix from the provided data, using the specified symmetry thresholds.

Parameters:

symmetryType - the type of symmetry enforced at construction

dataIn - the data of the matrix (must be a NxN array)

absoluteSymmetryThreshold - the absolute threshold above which off-diagonal elements are considered different
(if null, no check is done on the absolute difference between symmetric elements)

relativeSymmetryThreshold - the relative threshold above which off-diagonal elements are considered different
(if null, no check is done on the relative difference between symmetric elements)

Throws:

NonSquareMatrixException - if the provided matrix is not square (unchecked)

NonSymmetricMatrixException - if the provided matrix is not symmetric (unchecked)

ArrayRowSymmetricMatrix

public ArrayRowSymmetricMatrix(ArrayRowSymmetricMatrix.SymmetryType symmetryType,
                               RealMatrix matrix)

Builds a new ArrayRowSymmetricMatrix from the provided matrix, using the default symmetry thresholds.

Parameters:

symmetryType - the type of symmetry enforced at construction

matrix - the matrix (must NxN)

Throws:

NonSquareMatrixException - if the provided matrix is not square (unchecked)

NonSymmetricMatrixException - if the provided matrix is not symmetric (unchecked)

See Also:

getDefaultRelativeSymmetryThreshold()

ArrayRowSymmetricMatrix

public ArrayRowSymmetricMatrix(ArrayRowSymmetricMatrix.SymmetryType symmetryType,
                               RealMatrix matrix,
                               Double absoluteSymmetryThreshold,
                               Double relativeSymmetryThreshold)

Builds a new ArrayRowSymmetricMatrix from the provided matrix, using the specified symmetry thresholds.

Parameters:

symmetryType - the type of symmetry enforced at construction

matrix - the matrix (must NxN)

absoluteSymmetryThreshold - the absolute threshold above which off-diagonal elements are considered different
(if null, no check is done on the absolute difference between symmetric elements)

relativeSymmetryThreshold - the relative threshold above which off-diagonal elements are considered different
(if null, no check is done on the absolute difference between symmetric elements)

Throws:

NonSquareMatrixException - if the provided matrix is not square (unchecked)

NonSymmetricMatrixException - if the provided matrix is not symmetric (unchecked)

ArrayRowSymmetricMatrix

protected ArrayRowSymmetricMatrix(double[] dataIn,
                                  boolean copyArray)

Builds a new ArrayRowSymmetricMatrix by specifying the lower triangular part of the matrix directly.

Parameters:

dataIn - the array storing the lower triangular part of the matrix

copyArray - if true, copy the provided array instead

Method Detail

getRowDimension

public int getRowDimension()

Returns the number of rows of this matrix.

Specified by:

getRowDimension in interface AnyMatrix

Specified by:

getRowDimension in class AbstractRealMatrix

Returns:

the number of rows.

getColumnDimension

public int getColumnDimension()

Returns the number of columns of this matrix.

Specified by:

getColumnDimension in interface AnyMatrix

Specified by:

getColumnDimension in class AbstractRealMatrix

Returns:

the number of columns.

getInternalData

protected double[] getInternalData()

Gets the internal array storing the lower part of the symmetric matrix.

Returns:

the internal array storing the lower part of the symmetric matrix

getEntry

public double getEntry(int row,
                       int column)

Get the entry in the specified row and column. Row and column indices start at 0.

Specified by:

getEntry in interface RealMatrix

Specified by:

getEntry in class AbstractRealMatrix

Parameters:

row - Row index of entry to be fetched.

column - Column index of entry to be fetched.

Returns:

the matrix entry at (row, column).

setEntry

public void setEntry(int row,
                     int column,
                     double value)

Set the entry in the specified row and column. Row and column indices start at 0.

This method automatically modify the symmetric element to ensure the symmetry of the matrix is preserved.

Specified by:

setEntry in interface RealMatrix

Specified by:

setEntry in class AbstractRealMatrix

Parameters:

row - Row index of entry to be set.

column - Column index of entry to be set.

value - the new value of the entry.

scalarAdd

public ArrayRowSymmetricMatrix scalarAdd(double d)

Returns the result of adding d to each entry of this.

Specified by:

scalarAdd in interface RealMatrix

Specified by:

scalarAdd in interface SymmetricMatrix

Overrides:

scalarAdd in class AbstractRealMatrix

Parameters:

d - value to be added to each entry

Returns:

d + this

scalarMultiply

public ArrayRowSymmetricMatrix scalarMultiply(double d)

Returns the result of multiplying each entry of this by d.

Specified by:

scalarMultiply in interface RealMatrix

Specified by:

scalarMultiply in interface SymmetricMatrix

Overrides:

scalarMultiply in class AbstractRealMatrix

Parameters:

d - value to multiply all entries by

Returns:

d * this

add

public RealMatrix add(RealMatrix m)

Returns the sum of this and m.

Specified by:

add in interface RealMatrix

Overrides:

add in class AbstractRealMatrix

Parameters:

m - matrix to be added

Returns:

this + m

add

public ArrayRowSymmetricMatrix add(SymmetricMatrix m)

Adds a SymmetricMatrix to this matrix.

Specified by:

add in interface SymmetricMatrix

Parameters:

m - the matrix to add

Returns:

the matrix resulting from this addition

add

public ArrayRowSymmetricMatrix add(DiagonalMatrix m)

Compute the sum of this and m.

DiagonalMatrix method optimization

Parameters:

m - Diagonal matrix to be added

Returns:

this + m

Throws:

IllegalArgumentException - if m is not the same size as this

subtract

public RealMatrix subtract(RealMatrix m)

Returns this minus m.

Specified by:

subtract in interface RealMatrix

Overrides:

subtract in class AbstractRealMatrix

Parameters:

m - matrix to be subtracted

Returns:

this - m

subtract

public ArrayRowSymmetricMatrix subtract(SymmetricMatrix m)

Subtracts a SymmetricMatrix from this matrix.

Specified by:

subtract in interface SymmetricMatrix

Parameters:

m - the matrix to subtract

Returns:

the matrix resulting from this subtraction

subtract

public ArrayRowSymmetricMatrix subtract(DiagonalMatrix m)

Compute this minus m.

DiagonalMatrix method optimization

Parameters:

m - Diagonal matrix to be added

Returns:

this + m

Throws:

IllegalArgumentException - if m is not the same size as this

quadraticMultiplication

public ArrayRowSymmetricMatrix quadraticMultiplication(RealMatrix m)

Gets the result of the quadratic multiplication M×S×M^T, where S is this matrix and M is the provided matrix.

Specified by:

quadraticMultiplication in interface SymmetricMatrix

Parameters:

m - the matrix M

Returns:

M×S×M^T

quadraticMultiplication

public ArrayRowSymmetricMatrix quadraticMultiplication(RealMatrix m,
                                                       boolean isTranspose)

Gets the result of the quadratic multiplication M×S×M^T, where S is this matrix and M or M^T is the provided matrix.

Specified by:

quadraticMultiplication in interface SymmetricMatrix

Parameters:

m - the matrix M or the matrix M^T

isTranspose - if true, assume the provided matrix is M^T, otherwise assumes it is M

Returns:

M×S×M^T

createMatrix

public ArrayRowSymmetricMatrix createMatrix(int rowDimension,
                                            int columnDimension)

Create a new RealMatrix of the same type as the instance with the supplied row and column dimensions.

Specified by:

createMatrix in interface RealMatrix

Specified by:

createMatrix in class AbstractRealMatrix

Parameters:

rowDimension - the number of rows in the new matrix

columnDimension - the number of columns in the new matrix

Returns:

a new matrix of the same type as the instance

Throws:

DimensionMismatchException - if the row and column dimensions are not the same (unchecked)

getSubMatrix

public RealMatrix getSubMatrix(int startRow,
                               int endRow,
                               int startColumn,
                               int endColumn)

Gets a submatrix. Rows and columns are indicated counting from 0 to n-1.

Specified by:

getSubMatrix in interface RealMatrix

Overrides:

getSubMatrix in class AbstractRealMatrix

Parameters:

startRow - Initial row index

endRow - Final row index (inclusive)

startColumn - Initial column index

endColumn - Final column index (inclusive)

Returns:

The subMatrix containing the data of the specified rows and columns.

getSubMatrix

public RealMatrix getSubMatrix(int[] selectedRows,
                               int[] selectedColumns)

Gets a submatrix. Rows and columns are indicated counting from 0 to n-1.

Specified by:

getSubMatrix in interface RealMatrix

Overrides:

getSubMatrix in class AbstractRealMatrix

Parameters:

selectedRows - Array of row indices.

selectedColumns - Array of column indices.

Returns:

The subMatrix containing the data in the specified rows and columns

permutation

public ArrayRowSymmetricMatrix permutation(int[] index)

Permute the rows/columns of this matrix according to a new specified index order list.

The index list must be the same dimension as the matrix and each index must be represented.

 Usage example :
        1        2        3                            2       3        1
   1 [lambda1,      mu,   gamma]                 2 [lambda2,    beta,      mu]
   2 [     mu, lambda2,    beta] --> {2,3,1} --> 3 [   beta, lambda3,   gamma]
   3 [  gamma,    beta, lambda3]                 1 [     mu,   gamma, lambda1]
 

Specified by:

permutation in interface SymmetricMatrix

Parameters:

index - Index list of the expected permutation

Returns:

permuted matrix

copy

public ArrayRowSymmetricMatrix copy()

Returns a (deep) copy of this.

Specified by:

copy in interface RealMatrix

Specified by:

copy in interface SymmetricMatrix

Specified by:

copy in class AbstractRealMatrix

Returns:

matrix copy

transpose

public ArrayRowSymmetricMatrix transpose()

Returns the transpose of this matrix.

Specified by:

transpose in interface RealMatrix

Specified by:

transpose in interface SymmetricMatrix

Overrides:

transpose in class AbstractRealMatrix

Returns:

transpose matrix

getDefaultAbsoluteSymmetryThreshold

public static Double getDefaultAbsoluteSymmetryThreshold()

Gets the default absolute threshold above which off-diagonal elements are considered different.

A null value means the symmetry is enforced without any check on the absolute difference between symmetric elements.

Returns:

the default absolute symmetry threshold (≥0 or null)

See Also:

getDefaultRelativeSymmetryThreshold(), setDefaultAbsoluteSymmetryThreshold(Double), setDefaultRelativeSymmetryThreshold(Double)

setDefaultAbsoluteSymmetryThreshold

public static void setDefaultAbsoluteSymmetryThreshold(Double threshold)

Sets the default absolute threshold above which off-diagonal elements are considered different.

A null value means the symmetry is enforced without any check on the absolute difference between symmetric elements.

Parameters:

threshold - the new default relative symmetry threshold (≥0 or null)

See Also:

getDefaultAbsoluteSymmetryThreshold(), getDefaultRelativeSymmetryThreshold(), setDefaultRelativeSymmetryThreshold(Double)

getDefaultRelativeSymmetryThreshold

public static Double getDefaultRelativeSymmetryThreshold()

Gets the default relative threshold above which off-diagonal elements are considered different.

A null value means the symmetry is enforced without any check on the relative difference between symmetric elements.

Returns:

the default relative symmetry threshold (≥0 or null)

See Also:

getDefaultAbsoluteSymmetryThreshold(), setDefaultAbsoluteSymmetryThreshold(Double), setDefaultRelativeSymmetryThreshold(Double)

setDefaultRelativeSymmetryThreshold

public static void setDefaultRelativeSymmetryThreshold(Double threshold)

Sets the default relative threshold above which off-diagonal elements are considered different.

A null value means the symmetry is enforced without any check on the relative difference between symmetric elements.

Parameters:

threshold - the new default relative symmetry threshold (≥0 or null)

See Also:

getDefaultAbsoluteSymmetryThreshold(), getDefaultRelativeSymmetryThreshold(), setDefaultAbsoluteSymmetryThreshold(Double)

setSubMatrix

public void setSubMatrix(double[][] subMatrix,
                         int row,
                         int column)

The method systematically throws a MathUnsupportedOperationException as this operation is not safe when we deal with a SymmetricMatrix.

Specified by:

setSubMatrix in interface RealMatrix

Overrides:

setSubMatrix in class AbstractRealMatrix

Parameters:

subMatrix - matrix containing the submatrix replacement data

row - row coordinate of the top, left element to be replaced

column - column coordinate of the top, left element to be replaced

Throws:

MathUnsupportedOperationException - systematically, since this operation is not supported

Since:

4.5

setSubMatrix

public void setSubMatrix(RealMatrix subMatrix,
                         int row,
                         int column)

Method setSubMatrix using a RealMatrix for subMatrix instead of an array

Parameters:

subMatrix - matrix containing the submatrix replacement data

row - row coordinate of the top, left element to be replaced

column - column coordinate of the top, left element to be replaced

Throws:

MathUnsupportedOperationException - systematically, since this operation is not supported

Since:

4.5

addToEntry

public void addToEntry(int row,
                       int column,
                       double increment)

Adds (in place) the specified value to the specified entry of this matrix. Row and column indices start at 0.

Specified by:

addToEntry in interface RealMatrix

Overrides:

addToEntry in class AbstractRealMatrix

Parameters:

row - Row index of the entry to be modified.

column - Column index of the entry to be modified.

increment - value to add to the matrix entry.

multiplyEntry

public void multiplyEntry(int row,
                          int column,
                          double factor)

Multiplies (in place) the specified entry of this matrix by the specified value. Row and column indices start at 0.

Specified by:

multiplyEntry in interface RealMatrix

Overrides:

multiplyEntry in class AbstractRealMatrix

Parameters:

row - Row index of the entry to be modified.

column - Column index of the entry to be modified.

factor - Multiplication factor for the matrix entry.

getRowMatrix

public RealMatrix getRowMatrix(int row)

Get the entries at the given row index as a row matrix. Row indices start at 0.

Specified by:

getRowMatrix in interface RealMatrix

Overrides:

getRowMatrix in class AbstractRealMatrix

Parameters:

row - Row to be fetched.

Returns:

row Matrix.

getColumnMatrix

public RealMatrix getColumnMatrix(int column)

Get the entries at the given column index as a column matrix. Column indices start at 0.

Specified by:

getColumnMatrix in interface RealMatrix

Overrides:

getColumnMatrix in class AbstractRealMatrix

Parameters:

column - Column to be fetched.

Returns:

column Matrix.

getInverse

public ArrayRowSymmetricMatrix getInverse()

Get the inverse (or pseudo-inverse) of the decomposed matrix. The default decomposition can be changed using the setDefaultDecomposition(Decomposition) method. Default decomposition is used. Default decomposition is set to LUDecomposition.

Specified by:

getInverse in interface RealMatrix

Specified by:

getInverse in interface SymmetricMatrix

Overrides:

getInverse in class AbstractRealMatrix

Returns:

inverse matrix

getInverse

public ArrayRowSymmetricMatrix getInverse(Decomposition decomposition)

Get the inverse (or pseudo-inverse) matrix computed with the given decomposition algorithm.

Warning: If a matrix has already been given to the decomposition, it won't be taken into account, as a new computation will be run on this matrix and will erase the old decomposition data.

Specified by:

getInverse in interface RealMatrix

Specified by:

getInverse in interface SymmetricMatrix

Overrides:

getInverse in class AbstractRealMatrix

Parameters:

decomposition - decomposed matrix

Returns:

inverse matrix

power

public ArrayRowSymmetricMatrix power(int p)

Returns the result of multiplying this with itself p times. Depending on the underlying storage, instability for high powers might occur.

Specified by:

power in interface RealMatrix

Specified by:

power in interface SymmetricMatrix

Overrides:

power in class AbstractRealMatrix

Parameters:

p - raise this to power p

Returns:

this^p