DiagonalMatrix (Apache Commons Math 3.6.1 API)

java.lang.Object
- org.apache.commons.math3.linear.RealLinearOperator
- - org.apache.commons.math3.linear.AbstractRealMatrix
  - - 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:
Serialized Form

Constructor Summary

Constructors
Constructor and 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

Methods
Modifier and Type	Method and 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 Detail
  - 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 Detail
  - 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 Detail

DiagonalMatrix

DiagonalMatrix

DiagonalMatrix

Method Detail

createMatrix

copy

add

subtract

multiply

multiply

getData

getDataRef

getEntry

setEntry

addToEntry

multiplyEntry

getRowDimension

getColumnDimension

operate

preMultiply

preMultiply

inverse

inverse

isSingular