org.apache.commons.math3.linear.DiagonalMatrix

All Implemented Interfaces:: Serializable, AnyMatrix, RealMatrix

public class DiagonalMatrix extends AbstractRealMatrix implements Serializable

Implementation of a diagonal matrix.

Since:

3.1.1

See Also:

Constructor Summary

Constructors

Constructor

Description

DiagonalMatrix(double[] d)

Creates a matrix using the input array as the underlying data.

DiagonalMatrix(double[] d, boolean copyArray)

Creates a matrix using the input array as the underlying data.

DiagonalMatrix(int dimension)

Creates a matrix with the supplied dimension.
Method Summary

Modifier and Type

Method

Description

DiagonalMatrix

add(DiagonalMatrix m)

Compute the sum of this and m.

void

addToEntry(int row, int column, double increment)

Adds (in place) the specified value to the specified entry of this matrix.

RealMatrix

copy()

Returns a (deep) copy of this.

RealMatrix

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.

double[][]

getData()

Returns matrix entries as a two-dimensional array.

double[]

getDataRef()

Gets a reference to the underlying data array.

double

getEntry(int row, int column)

Get the entry in the specified row and column.

int

getRowDimension()

Returns the number of rows of this matrix.

DiagonalMatrix

inverse()

Computes the inverse of this diagonal matrix.

DiagonalMatrix

inverse(double threshold)

Computes the inverse of this diagonal matrix.

boolean

isSingular(double threshold)

Returns whether this diagonal matrix is singular, i.e.

DiagonalMatrix

multiply(DiagonalMatrix m)

Returns the result of postmultiplying this by m.

RealMatrix

multiply(RealMatrix m)

Returns the result of postmultiplying this by m.

void

multiplyEntry(int row, int column, double factor)

Multiplies (in place) the specified entry of this matrix by the specified value.

double[]

operate(double[] v)

Returns the result of multiplying this by the vector v.

double[]

preMultiply(double[] v)

Returns the (row) vector result of premultiplying this by the vector v.

RealVector

preMultiply(RealVector v)

Returns the (row) vector result of premultiplying this by the vector v.

void

setEntry(int row, int column, double value)

Set the entry in the specified row and column.

DiagonalMatrix

subtract(DiagonalMatrix m)

Returns this minus m.

Methods inherited from class org.apache.commons.math3.linear.AbstractRealMatrix
add, copySubMatrix, copySubMatrix, equals, getColumn, getColumnMatrix, getColumnVector, getFrobeniusNorm, getNorm, getRow, getRowMatrix, getRowVector, getSubMatrix, getSubMatrix, getTrace, hashCode, isSquare, operate, power, preMultiply, scalarAdd, scalarMultiply, setColumn, setColumnMatrix, setColumnVector, setRow, setRowMatrix, setRowVector, setSubMatrix, subtract, toString, transpose, walkInColumnOrder, walkInColumnOrder, walkInColumnOrder, walkInColumnOrder, walkInOptimizedOrder, walkInOptimizedOrder, walkInOptimizedOrder, walkInOptimizedOrder, walkInRowOrder, walkInRowOrder, walkInRowOrder, walkInRowOrder

Methods inherited from class org.apache.commons.math3.linear.RealLinearOperator
isTransposable, operateTranspose

Methods inherited from class java.lang.Object
clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Constructor Details
- DiagonalMatrix
  
  public DiagonalMatrix(int dimension) throws NotStrictlyPositiveException
  
  Creates a matrix with the supplied dimension.
  
  Parameters:
  
  dimension - Number of rows and columns in the new matrix.
  
  Throws:
  
  NotStrictlyPositiveException - if the dimension is not positive.
- DiagonalMatrix
  
  public DiagonalMatrix(double[] d)
  
  Creates a matrix using the input array as the underlying data.
  The input array is copied, not referenced.
  
  Parameters:
  
  d - Data for the new matrix.
- DiagonalMatrix
  
  public DiagonalMatrix(double[] d, boolean copyArray) throws NullArgumentException
  
  Creates a matrix using the input array as the underlying data.
  If an array is created specially in order to be embedded in a this instance and not used directly, the copyArray may be set to false. This will prevent the copying and improve performance as no new array will be built and no data will be copied.
  
  Parameters:
  
  d - Data for new matrix.
  
  copyArray - if true, the input array will be copied, otherwise it will be referenced.
  
  Throws:
  
  NullArgumentException - if d is null
Method Details
- createMatrix
  
  public RealMatrix createMatrix(int rowDimension, int columnDimension) throws NotStrictlyPositiveException, DimensionMismatchException
  
  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 requested dimensions are not equal.
  
  NotStrictlyPositiveException - if row or column dimension is not positive.
- copy
  
  public RealMatrix copy()
  
  Returns a (deep) copy of this.
  
  Specified by:
  
  copy in interface RealMatrix
  
  Specified by:
  
  copy in class AbstractRealMatrix
  
  Returns:
  
  matrix copy
- add
  
  public DiagonalMatrix add(DiagonalMatrix m) throws MatrixDimensionMismatchException
  
  Compute the sum of this and m.
  
  Parameters:
  
  m - Matrix to be added.
  
  Returns:
  
  this + m.
  
  Throws:
  
  MatrixDimensionMismatchException - if m is not the same size as this.
- subtract
  
  public DiagonalMatrix subtract(DiagonalMatrix m) throws MatrixDimensionMismatchException
  
  Returns this minus m.
  
  Parameters:
  
  m - Matrix to be subtracted.
  
  Returns:
  
  this - m
  
  Throws:
  
  MatrixDimensionMismatchException - if m is not the same size as this.
- multiply
  
  public DiagonalMatrix multiply(DiagonalMatrix m) throws DimensionMismatchException
  
  Returns the result of postmultiplying this by m.
  
  Parameters:
  
  m - matrix to postmultiply by
  
  Returns:
  
  this * m
  
  Throws:
  
  DimensionMismatchException - if columnDimension(this) != rowDimension(m)
- multiply
  
  public RealMatrix multiply(RealMatrix m) throws DimensionMismatchException
  
  Returns the result of postmultiplying this by m.
  
  Specified by:
  
  multiply in interface RealMatrix
  
  Overrides:
  
  multiply in class AbstractRealMatrix
  
  Parameters:
  
  m - matrix to postmultiply by
  
  Returns:
  
  this * m
  
  Throws:
  
  DimensionMismatchException - if columnDimension(this) != rowDimension(m)
- getData
  
  public double[][] getData()
  
  Returns matrix entries as a two-dimensional array.
  
  Specified by:
  
  getData in interface RealMatrix
  
  Overrides:
  
  getData in class AbstractRealMatrix
  
  Returns:
  
  2-dimensional array of entries
- getDataRef
  
  public double[] getDataRef()
  
  Gets a reference to the underlying data array.
  
  Returns:
  
  1-dimensional array of entries.
- getEntry
  
  public double getEntry(int row, int column) throws OutOfRangeException
  
  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).
  
  Throws:
  
  OutOfRangeException - if the row or column index is not valid.
- setEntry
  
  public void setEntry(int row, int column, double value) throws OutOfRangeException, NumberIsTooLargeException
  
  Set the entry in the specified row and column. Row and column indices start at 0.
  
  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.
  
  Throws:
  
  NumberIsTooLargeException - if row != column and value is non-zero.
  
  OutOfRangeException - if the row or column index is not valid
- addToEntry
  
  public void addToEntry(int row, int column, double increment) throws OutOfRangeException, NumberIsTooLargeException
  
  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.
  
  Throws:
  
  NumberIsTooLargeException - if row != column and increment is non-zero.
  
  OutOfRangeException - if the row or column index is not valid.
- multiplyEntry
  
  public void multiplyEntry(int row, int column, double factor) throws OutOfRangeException
  
  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.
  
  Throws:
  
  OutOfRangeException - if the row or column index is not valid.
- 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.
- operate
  
  public double[] operate(double[] v) throws DimensionMismatchException
  
  Returns the result of multiplying this by the vector v.
  
  Specified by:
  
  operate in interface RealMatrix
  
  Overrides:
  
  operate in class AbstractRealMatrix
  
  Parameters:
  
  v - the vector to operate on
  
  Returns:
  
  this * v
  
  Throws:
  
  DimensionMismatchException - if the length of v does not match the column dimension of this.
- preMultiply
  
  public double[] preMultiply(double[] v) throws DimensionMismatchException
  
  Returns the (row) vector result of premultiplying this by the vector v.
  
  Specified by:
  
  preMultiply in interface RealMatrix
  
  Overrides:
  
  preMultiply in class AbstractRealMatrix
  
  Parameters:
  
  v - the row vector to premultiply by
  
  Returns:
  
  v * this
  
  Throws:
  
  DimensionMismatchException - if the length of v does not match the row dimension of this.
- preMultiply
  
  public RealVector preMultiply(RealVector v) throws DimensionMismatchException
  
  Returns the (row) vector result of premultiplying this by the vector v.
  
  Specified by:
  
  preMultiply in interface RealMatrix
  
  Overrides:
  
  preMultiply in class AbstractRealMatrix
  
  Parameters:
  
  v - the row vector to premultiply by
  
  Returns:
  
  v * this
  
  Throws:
  
  DimensionMismatchException - if the dimension of v does not match the row dimension of this.
- inverse
  
  public DiagonalMatrix inverse() throws SingularMatrixException
  
  Computes the inverse of this diagonal matrix.
  Note: this method will use a singularity threshold of 0, use inverse(double) if a different threshold is needed.
  
  Returns:
  
  the inverse of m
  
  Throws:
  
  SingularMatrixException - if the matrix is singular
  
  Since:
  
  3.3
- inverse
  
  public DiagonalMatrix inverse(double threshold) throws SingularMatrixException
  
  Computes the inverse of this diagonal matrix.
  
  Parameters:
  
  threshold - Singularity threshold.
  
  Returns:
  
  the inverse of m
  
  Throws:
  
  SingularMatrixException - if the matrix is singular
  
  Since:
  
  3.3
- isSingular
  
  public boolean isSingular(double threshold)
  
  Returns whether this diagonal matrix is singular, i.e. any diagonal entry is equal to 0 within the given threshold.
  
  Parameters:
  
  threshold - Singularity threshold.
  
  Returns:
  
  true if the matrix is singular, false otherwise
  
  Since:
  
  3.3

Class DiagonalMatrix

Constructor Summary

Method Summary

Methods inherited from class org.apache.commons.math3.linear.AbstractRealMatrix

Methods inherited from class org.apache.commons.math3.linear.RealLinearOperator

Methods inherited from class java.lang.Object

Constructor Details

DiagonalMatrix

DiagonalMatrix

DiagonalMatrix

Method Details

createMatrix

copy

add

subtract

multiply

multiply

getData

getDataRef

getEntry

setEntry

addToEntry

multiplyEntry

getRowDimension

getColumnDimension

operate

preMultiply

preMultiply

inverse

inverse

isSingular