AbstractRealMatrix (Apache Commons Math 3.6.1 API)

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

All Implemented Interfaces:

AnyMatrix, RealMatrix

Direct Known Subclasses:

Array2DRowRealMatrix, BlockRealMatrix, DiagonalMatrix, OpenMapRealMatrix
```
public abstract class AbstractRealMatrix
extends RealLinearOperator
implements RealMatrix
```
Basic implementation of RealMatrix methods regardless of the underlying storage.
All the methods implemented here use getEntry(int, int) to access matrix elements. Derived class can provide faster implementations.

Since:

2.0

Constructor Summary

Constructors
Modifier	Constructor and Description
`protected`	`AbstractRealMatrix()` Creates a matrix with no data
`protected`	`AbstractRealMatrix(int rowDimension, int columnDimension)` Create a new RealMatrix with the supplied row and column dimensions.

Method Summary

Methods
Modifier and Type	Method and Description
`RealMatrix`	`add(RealMatrix m)` Returns 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.
`abstract RealMatrix`	`copy()` Returns a (deep) copy of this.
`void`	`copySubMatrix(int[] selectedRows, int[] selectedColumns, double[][] destination)` Copy a submatrix.
`void`	`copySubMatrix(int startRow, int endRow, int startColumn, int endColumn, double[][] destination)` Copy a submatrix.
`abstract RealMatrix`	`createMatrix(int rowDimension, int columnDimension)` Create a new RealMatrix of the same type as the instance with the supplied row and column dimensions.
`boolean`	`equals(Object object)` Returns true iff `object` is a `RealMatrix` instance with the same dimensions as this and all corresponding matrix entries are equal.
`double[]`	`getColumn(int column)` Get the entries at the given column index as an array.
`abstract 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.
`RealVector`	`getColumnVector(int column)` Get the entries at the given column index as a vector.
`double[][]`	`getData()` Returns matrix entries as a two-dimensional array.
`abstract double`	`getEntry(int row, int column)` Get the entry in the specified row and column.
`double`	`getFrobeniusNorm()` Returns the Frobenius norm of the matrix.
`double`	`getNorm()` Returns the maximum absolute row sum norm of the matrix.
`double[]`	`getRow(int row)` Get the entries at the given row index.
`abstract 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.
`RealVector`	`getRowVector(int row)` Returns the entries in row number `row` as a vector.
`RealMatrix`	`getSubMatrix(int[] selectedRows, int[] selectedColumns)` Gets a submatrix.
`RealMatrix`	`getSubMatrix(int startRow, int endRow, int startColumn, int endColumn)` Gets a submatrix.
`double`	`getTrace()` Returns the trace of the matrix (the sum of the elements on the main diagonal).
`int`	`hashCode()` Computes a hashcode for the matrix.
`boolean`	`isSquare()` Is this a square matrix?
`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`.
`RealVector`	`operate(RealVector v)` Returns the result of multiplying `this` by the vector `x`.
`RealMatrix`	`power(int p)` Returns the result of multiplying `this` with itself `p` times.
`double[]`	`preMultiply(double[] v)` Returns the (row) vector result of premultiplying this by the vector `v`.
`RealMatrix`	`preMultiply(RealMatrix m)` Returns the result of premultiplying `this` by `m`.
`RealVector`	`preMultiply(RealVector v)` Returns the (row) vector result of premultiplying this by the vector `v`.
`RealMatrix`	`scalarAdd(double d)` Returns the result of adding `d` to each entry of `this`.
`RealMatrix`	`scalarMultiply(double d)` Returns the result of multiplying each entry of `this` by `d`.
`void`	`setColumn(int column, double[] array)` Sets the specified `column` of `this` matrix to the entries of the specified `array`.
`void`	`setColumnMatrix(int column, RealMatrix matrix)` Sets the specified `column` of `this` matrix to the entries of the specified column `matrix`.
`void`	`setColumnVector(int column, RealVector vector)` Sets the specified `column` of `this` matrix to the entries of the specified `vector`.
`abstract void`	`setEntry(int row, int column, double value)` Set the entry in the specified row and column.
`void`	`setRow(int row, double[] array)` Sets the specified `row` of `this` matrix to the entries of the specified `array`.
`void`	`setRowMatrix(int row, RealMatrix matrix)` Sets the specified `row` of `this` matrix to the entries of the specified row `matrix`.
`void`	`setRowVector(int row, RealVector vector)` Sets the specified `row` of `this` matrix to the entries of the specified `vector`.
`void`	`setSubMatrix(double[][] subMatrix, int row, int column)` Replace the submatrix starting at `row, column` using data in the input `subMatrix` array.
`RealMatrix`	`subtract(RealMatrix m)` Returns `this` minus `m`.
`String`	`toString()` Get a string representation for this matrix.
`RealMatrix`	`transpose()` Returns the transpose of this matrix.
`double`	`walkInColumnOrder(RealMatrixChangingVisitor visitor)` Visit (and possibly change) all matrix entries in column order.
`double`	`walkInColumnOrder(RealMatrixChangingVisitor visitor, int startRow, int endRow, int startColumn, int endColumn)` Visit (and possibly change) some matrix entries in column order.
`double`	`walkInColumnOrder(RealMatrixPreservingVisitor visitor)` Visit (but don't change) all matrix entries in column order.
`double`	`walkInColumnOrder(RealMatrixPreservingVisitor visitor, int startRow, int endRow, int startColumn, int endColumn)` Visit (but don't change) some matrix entries in column order.
`double`	`walkInOptimizedOrder(RealMatrixChangingVisitor visitor)` Visit (and possibly change) all matrix entries using the fastest possible order.
`double`	`walkInOptimizedOrder(RealMatrixChangingVisitor visitor, int startRow, int endRow, int startColumn, int endColumn)` Visit (and possibly change) some matrix entries using the fastest possible order.
`double`	`walkInOptimizedOrder(RealMatrixPreservingVisitor visitor)` Visit (but don't change) all matrix entries using the fastest possible order.
`double`	`walkInOptimizedOrder(RealMatrixPreservingVisitor visitor, int startRow, int endRow, int startColumn, int endColumn)` Visit (but don't change) some matrix entries using the fastest possible order.
`double`	`walkInRowOrder(RealMatrixChangingVisitor visitor)` Visit (and possibly change) all matrix entries in row order.
`double`	`walkInRowOrder(RealMatrixChangingVisitor visitor, int startRow, int endRow, int startColumn, int endColumn)` Visit (and possibly change) some matrix entries in row order.
`double`	`walkInRowOrder(RealMatrixPreservingVisitor visitor)` Visit (but don't change) all matrix entries in row order.
`double`	`walkInRowOrder(RealMatrixPreservingVisitor visitor, int startRow, int endRow, int startColumn, int endColumn)` Visit (but don't change) some matrix entries in row order.

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
  - AbstractRealMatrix
```
protected AbstractRealMatrix()
```
    Creates a matrix with no data
  - AbstractRealMatrix
```
protected AbstractRealMatrix(int rowDimension,
                  int columnDimension)
                      throws NotStrictlyPositiveException
```
    Create a new RealMatrix with the supplied row and column dimensions.
    
    Parameters:
    rowDimension - the number of rows in the new matrix
    columnDimension - the number of columns in the new matrix
    
    Throws:
    
    NotStrictlyPositiveException - if row or column dimension is not positive
- Method Detail
  - add
```
public RealMatrix add(RealMatrix m)
               throws MatrixDimensionMismatchException
```
    Returns the sum of this and m.
    
    Specified by:
    
    add in interface RealMatrix
    
    Parameters:
    m - matrix to be added
    
    Returns:
    this + m
    
    Throws:
    
    MatrixDimensionMismatchException - if m is not the same size as this.
  - subtract
```
public RealMatrix subtract(RealMatrix m)
                    throws MatrixDimensionMismatchException
```
    Returns this minus m.
    
    Specified by:
    
    subtract in interface RealMatrix
    
    Parameters:
    m - matrix to be subtracted
    
    Returns:
    this - m
    
    Throws:
    
    MatrixDimensionMismatchException - if m is not the same size as this.
  - scalarAdd
```
public RealMatrix scalarAdd(double d)
```
    Returns the result of adding d to each entry of this.
    
    Specified by:
    
    scalarAdd in interface RealMatrix
    
    Parameters:
    d - value to be added to each entry
    
    Returns:
    d + this
  - scalarMultiply
```
public RealMatrix scalarMultiply(double d)
```
    Returns the result of multiplying each entry of this by d.
    
    Specified by:
    
    scalarMultiply in interface RealMatrix
    
    Parameters:
    d - value to multiply all entries by
    
    Returns:
    d * this
  - multiply
```
public RealMatrix multiply(RealMatrix m)
                    throws DimensionMismatchException
```
    Returns the result of postmultiplying this by m.
    
    Specified by:
    
    multiply in interface RealMatrix
    
    Parameters:
    m - matrix to postmultiply by
    
    Returns:
    this * m
    
    Throws:
    
    DimensionMismatchException - if columnDimension(this) != rowDimension(m)
  - preMultiply
```
public RealMatrix preMultiply(RealMatrix m)
                       throws DimensionMismatchException
```
    Returns the result of premultiplying this by m.
    
    Specified by:
    
    preMultiply in interface RealMatrix
    
    Parameters:
    m - matrix to premultiply by
    
    Returns:
    m * this
    
    Throws:
    
    DimensionMismatchException - if rowDimension(this) != columnDimension(m)
  - power
```
public RealMatrix power(int p)
                 throws NotPositiveException,
                        NonSquareMatrixException
```
    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
    
    Parameters:
    p - raise this to power p
    
    Returns:
    this^p
    
    Throws:
    
    NotPositiveException - if p < 0
    
    NonSquareMatrixException - if the matrix is not square
  - getData
```
public double[][] getData()
```
    Returns matrix entries as a two-dimensional array.
    
    Specified by:
    
    getData in interface RealMatrix
    
    Returns:
    2-dimensional array of entries
  - getNorm
```
public double getNorm()
```
    Returns the maximum absolute row sum norm of the matrix.
    
    Specified by:
    
    getNorm in interface RealMatrix
    
    Returns:
    norm
  - getFrobeniusNorm
```
public double getFrobeniusNorm()
```
    Returns the Frobenius norm of the matrix.
    
    Specified by:
    
    getFrobeniusNorm in interface RealMatrix
    
    Returns:
    norm
  - getSubMatrix
```
public RealMatrix getSubMatrix(int startRow,
                      int endRow,
                      int startColumn,
                      int endColumn)
                        throws OutOfRangeException,
                               NumberIsTooSmallException
```
    Gets a submatrix. Rows and columns are indicated counting from 0 to n-1.
    
    Specified by:
    
    getSubMatrix in interface RealMatrix
    
    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.
    
    Throws:
    
    OutOfRangeException - if the indices are not valid.
    
    NumberIsTooSmallException - if endRow < startRow or endColumn < startColumn.
  - getSubMatrix
```
public RealMatrix getSubMatrix(int[] selectedRows,
                      int[] selectedColumns)
                        throws NullArgumentException,
                               NoDataException,
                               OutOfRangeException
```
    Gets a submatrix. Rows and columns are indicated counting from 0 to n-1.
    
    Specified by:
    
    getSubMatrix in interface RealMatrix
    
    Parameters:
    selectedRows - Array of row indices.
    selectedColumns - Array of column indices.
    
    Returns:
    The subMatrix containing the data in the specified rows and columns
    
    Throws:
    
    NullArgumentException - if the row or column selections are null
    
    NoDataException - if the row or column selections are empty (zero length).
    
    OutOfRangeException - if the indices are not valid.
  - copySubMatrix
```
public void copySubMatrix(int startRow,
                 int endRow,
                 int startColumn,
                 int endColumn,
                 double[][] destination)
                   throws OutOfRangeException,
                          NumberIsTooSmallException,
                          MatrixDimensionMismatchException
```
    Copy a submatrix. Rows and columns are indicated counting from 0 to n-1.
    
    Specified by:
    
    copySubMatrix in interface RealMatrix
    
    Parameters:
    startRow - Initial row index
    endRow - Final row index (inclusive)
    startColumn - Initial column index
    endColumn - Final column index (inclusive)
    destination - The arrays where the submatrix data should be copied (if larger than rows/columns counts, only the upper-left part will be used)
    
    Throws:
    
    OutOfRangeException - if the indices are not valid.
    
    NumberIsTooSmallException - if endRow < startRow or endColumn < startColumn.
    
    MatrixDimensionMismatchException - if the destination array is too small.
  - copySubMatrix
```
public void copySubMatrix(int[] selectedRows,
                 int[] selectedColumns,
                 double[][] destination)
                   throws OutOfRangeException,
                          NullArgumentException,
                          NoDataException,
                          MatrixDimensionMismatchException
```
    Copy a submatrix. Rows and columns are indicated counting from 0 to n-1.
    
    Specified by:
    
    copySubMatrix in interface RealMatrix
    
    Parameters:
    selectedRows - Array of row indices.
    selectedColumns - Array of column indices.
    destination - The arrays where the submatrix data should be copied (if larger than rows/columns counts, only the upper-left part will be used)
    
    Throws:
    
    OutOfRangeException - if the indices are not valid.
    
    NullArgumentException - if the row or column selections are null
    
    NoDataException - if the row or column selections are empty (zero length).
    
    MatrixDimensionMismatchException - if the destination array is too small.
  - setSubMatrix
```
public void setSubMatrix(double[][] subMatrix,
                int row,
                int column)
                  throws NoDataException,
                         OutOfRangeException,
                         DimensionMismatchException,
                         NullArgumentException
```
    Replace the submatrix starting at row, column using data in the input subMatrix array. Indexes are 0-based.
    Example:
    Starting with
```
 1  2  3  4
 5  6  7  8
 9  0  1  2
 
```
    and subMatrix = {{3, 4} {5,6}}, invoking setSubMatrix(subMatrix,1,1)) will result in
```
 1  2  3  4
 5  3  4  8
 9  5  6  2
 
```
    Specified by:
    
    setSubMatrix in interface RealMatrix
    
    Parameters:
    subMatrix - array 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:
    
    NoDataException - if subMatrix is empty.
    
    OutOfRangeException - if subMatrix does not fit into this matrix from element in (row, column).
    
    DimensionMismatchException - if subMatrix is not rectangular (not all rows have the same length) or empty.
    
    NullArgumentException - if subMatrix is null.
  - getRowMatrix
```
public RealMatrix getRowMatrix(int row)
                        throws OutOfRangeException
```
    Get the entries at the given row index as a row matrix. Row indices start at 0.
    
    Specified by:
    
    getRowMatrix in interface RealMatrix
    
    Parameters:
    row - Row to be fetched.
    
    Returns:
    row Matrix.
    
    Throws:
    
    OutOfRangeException - if the specified row index is invalid.
  - setRowMatrix
```
public void setRowMatrix(int row,
                RealMatrix matrix)
                  throws OutOfRangeException,
                         MatrixDimensionMismatchException
```
    Sets the specified row of this matrix to the entries of the specified row matrix. Row indices start at 0.
    
    Specified by:
    
    setRowMatrix in interface RealMatrix
    
    Parameters:
    row - Row to be set.
    matrix - Row matrix to be copied (must have one row and the same number of columns as the instance).
    
    Throws:
    
    OutOfRangeException - if the specified row index is invalid.
    
    MatrixDimensionMismatchException - if the row dimension of the matrix is not 1, or the column dimensions of this and matrix do not match.
  - getColumnMatrix
```
public RealMatrix getColumnMatrix(int column)
                           throws OutOfRangeException
```
    Get the entries at the given column index as a column matrix. Column indices start at 0.
    
    Specified by:
    
    getColumnMatrix in interface RealMatrix
    
    Parameters:
    column - Column to be fetched.
    
    Returns:
    column Matrix.
    
    Throws:
    
    OutOfRangeException - if the specified column index is invalid.
  - setColumnMatrix
```
public void setColumnMatrix(int column,
                   RealMatrix matrix)
                     throws OutOfRangeException,
                            MatrixDimensionMismatchException
```
    Sets the specified column of this matrix to the entries of the specified column matrix. Column indices start at 0.
    
    Specified by:
    
    setColumnMatrix in interface RealMatrix
    
    Parameters:
    column - Column to be set.
    matrix - Column matrix to be copied (must have one column and the same number of rows as the instance).
    
    Throws:
    
    OutOfRangeException - if the specified column index is invalid.
    
    MatrixDimensionMismatchException - if the column dimension of the matrix is not 1, or the row dimensions of this and matrix do not match.
  - getRowVector
```
public RealVector getRowVector(int row)
                        throws OutOfRangeException
```
    Returns the entries in row number row as a vector. Row indices start at 0.
    
    Specified by:
    
    getRowVector in interface RealMatrix
    
    Parameters:
    row - Row to be fetched.
    
    Returns:
    a row vector.
    
    Throws:
    
    OutOfRangeException - if the specified row index is invalid.
  - setRowVector
```
public void setRowVector(int row,
                RealVector vector)
                  throws OutOfRangeException,
                         MatrixDimensionMismatchException
```
    Sets the specified row of this matrix to the entries of the specified vector. Row indices start at 0.
    
    Specified by:
    
    setRowVector in interface RealMatrix
    
    Parameters:
    row - Row to be set.
    vector - row vector to be copied (must have the same number of column as the instance).
    
    Throws:
    
    OutOfRangeException - if the specified row index is invalid.
    
    MatrixDimensionMismatchException - if the vector dimension does not match the column dimension of this matrix.
  - getColumnVector
```
public RealVector getColumnVector(int column)
                           throws OutOfRangeException
```
    Get the entries at the given column index as a vector. Column indices start at 0.
    
    Specified by:
    
    getColumnVector in interface RealMatrix
    
    Parameters:
    column - Column to be fetched.
    
    Returns:
    a column vector.
    
    Throws:
    
    OutOfRangeException - if the specified column index is invalid
  - setColumnVector
```
public void setColumnVector(int column,
                   RealVector vector)
                     throws OutOfRangeException,
                            MatrixDimensionMismatchException
```
    Sets the specified column of this matrix to the entries of the specified vector. Column indices start at 0.
    
    Specified by:
    
    setColumnVector in interface RealMatrix
    
    Parameters:
    column - Column to be set.
    vector - column vector to be copied (must have the same number of rows as the instance).
    
    Throws:
    
    OutOfRangeException - if the specified column index is invalid.
    
    MatrixDimensionMismatchException - if the vector dimension does not match the row dimension of this matrix.
  - getRow
```
public double[] getRow(int row)
                throws OutOfRangeException
```
    Get the entries at the given row index. Row indices start at 0.
    
    Specified by:
    
    getRow in interface RealMatrix
    
    Parameters:
    row - Row to be fetched.
    
    Returns:
    the array of entries in the row.
    
    Throws:
    
    OutOfRangeException - if the specified row index is not valid.
  - setRow
```
public void setRow(int row,
          double[] array)
            throws OutOfRangeException,
                   MatrixDimensionMismatchException
```
    Sets the specified row of this matrix to the entries of the specified array. Row indices start at 0.
    
    Specified by:
    
    setRow in interface RealMatrix
    
    Parameters:
    row - Row to be set.
    array - Row matrix to be copied (must have the same number of columns as the instance)
    
    Throws:
    
    OutOfRangeException - if the specified row index is invalid.
    
    MatrixDimensionMismatchException - if the array length does not match the column dimension of this matrix.
  - getColumn
```
public double[] getColumn(int column)
                   throws OutOfRangeException
```
    Get the entries at the given column index as an array. Column indices start at 0.
    
    Specified by:
    
    getColumn in interface RealMatrix
    
    Parameters:
    column - Column to be fetched.
    
    Returns:
    the array of entries in the column.
    
    Throws:
    
    OutOfRangeException - if the specified column index is not valid.
  - setColumn
```
public void setColumn(int column,
             double[] array)
               throws OutOfRangeException,
                      MatrixDimensionMismatchException
```
    Sets the specified column of this matrix to the entries of the specified array. Column indices start at 0.
    
    Specified by:
    
    setColumn in interface RealMatrix
    
    Parameters:
    column - Column to be set.
    array - Column array to be copied (must have the same number of rows as the instance).
    
    Throws:
    
    OutOfRangeException - if the specified column index is invalid.
    
    MatrixDimensionMismatchException - if the array length does not match the row dimension of this matrix.
  - addToEntry
```
public void addToEntry(int row,
              int column,
              double increment)
                throws OutOfRangeException
```
    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
    
    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:
    
    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
    
    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.
  - transpose
```
public RealMatrix transpose()
```
    Returns the transpose of this matrix.
    
    Specified by:
    
    transpose in interface RealMatrix
    
    Returns:
    transpose matrix
  - isSquare
```
public boolean isSquare()
```
    Is this a square matrix?
    
    Specified by:
    
    isSquare in interface AnyMatrix
    
    Returns:
    true if the matrix is square (rowDimension = columnDimension)
  - getRowDimension
```
public abstract int getRowDimension()
```
    Returns the number of rows of this matrix.
    
    Specified by:
    
    getRowDimension in interface AnyMatrix
    
    Specified by:
    
    getRowDimension in class RealLinearOperator
    
    Returns:
    the number of rows.
  - getColumnDimension
```
public abstract int getColumnDimension()
```
    Returns the number of columns of this matrix.
    
    Specified by:
    
    getColumnDimension in interface AnyMatrix
    
    Specified by:
    
    getColumnDimension in class RealLinearOperator
    
    Returns:
    the number of columns.
  - getTrace
```
public double getTrace()
                throws NonSquareMatrixException
```
    Returns the trace of the matrix (the sum of the elements on the main diagonal).
    
    Specified by:
    
    getTrace in interface RealMatrix
    
    Returns:
    the trace.
    
    Throws:
    
    NonSquareMatrixException - if the matrix is not square.
  - operate
```
public double[] operate(double[] v)
                 throws DimensionMismatchException
```
    Returns the result of multiplying this by the vector v.
    
    Specified by:
    
    operate in interface RealMatrix
    
    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.
  - operate
```
public RealVector operate(RealVector v)
                   throws DimensionMismatchException
```
    Returns the result of multiplying this by the vector x.
    
    Specified by:
    
    operate in interface RealMatrix
    
    Specified by:
    
    operate in class RealLinearOperator
    
    Parameters:
    v - the vector to operate on
    
    Returns:
    the product of this instance with x
    
    Throws:
    
    DimensionMismatchException - if the column dimension does not match the size of x
  - 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
    
    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
    
    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.
  - walkInRowOrder
```
public double walkInRowOrder(RealMatrixChangingVisitor visitor)
```
    Visit (and possibly change) all matrix entries in row order.
    Row order starts at upper left and iterating through all elements of a row from left to right before going to the leftmost element of the next row.
    
    Specified by:
    
    walkInRowOrder in interface RealMatrix
    
    Parameters:
    visitor - visitor used to process all matrix entries
    
    Returns:
    the value returned by RealMatrixChangingVisitor.end() at the end of the walk
    See Also:
    RealMatrix.walkInRowOrder(RealMatrixPreservingVisitor), RealMatrix.walkInRowOrder(RealMatrixChangingVisitor, int, int, int, int), RealMatrix.walkInRowOrder(RealMatrixPreservingVisitor, int, int, int, int), RealMatrix.walkInColumnOrder(RealMatrixChangingVisitor), RealMatrix.walkInColumnOrder(RealMatrixPreservingVisitor), RealMatrix.walkInColumnOrder(RealMatrixChangingVisitor, int, int, int, int), RealMatrix.walkInColumnOrder(RealMatrixPreservingVisitor, int, int, int, int), RealMatrix.walkInOptimizedOrder(RealMatrixChangingVisitor), RealMatrix.walkInOptimizedOrder(RealMatrixPreservingVisitor), RealMatrix.walkInOptimizedOrder(RealMatrixChangingVisitor, int, int, int, int), RealMatrix.walkInOptimizedOrder(RealMatrixPreservingVisitor, int, int, int, int)
  - walkInRowOrder
```
public double walkInRowOrder(RealMatrixPreservingVisitor visitor)
```
    Visit (but don't change) all matrix entries in row order.
    Row order starts at upper left and iterating through all elements of a row from left to right before going to the leftmost element of the next row.
    
    Specified by:
    
    walkInRowOrder in interface RealMatrix
    
    Parameters:
    visitor - visitor used to process all matrix entries
    
    Returns:
    the value returned by RealMatrixPreservingVisitor.end() at the end of the walk
    See Also:
    RealMatrix.walkInRowOrder(RealMatrixChangingVisitor), RealMatrix.walkInRowOrder(RealMatrixChangingVisitor, int, int, int, int), RealMatrix.walkInRowOrder(RealMatrixPreservingVisitor, int, int, int, int), RealMatrix.walkInColumnOrder(RealMatrixChangingVisitor), RealMatrix.walkInColumnOrder(RealMatrixPreservingVisitor), RealMatrix.walkInColumnOrder(RealMatrixChangingVisitor, int, int, int, int), RealMatrix.walkInColumnOrder(RealMatrixPreservingVisitor, int, int, int, int), RealMatrix.walkInOptimizedOrder(RealMatrixChangingVisitor), RealMatrix.walkInOptimizedOrder(RealMatrixPreservingVisitor), RealMatrix.walkInOptimizedOrder(RealMatrixChangingVisitor, int, int, int, int), RealMatrix.walkInOptimizedOrder(RealMatrixPreservingVisitor, int, int, int, int)
  - walkInRowOrder
```
public double walkInRowOrder(RealMatrixChangingVisitor visitor,
                    int startRow,
                    int endRow,
                    int startColumn,
                    int endColumn)
                      throws OutOfRangeException,
                             NumberIsTooSmallException
```
    Visit (and possibly change) some matrix entries in row order.
    Row order starts at upper left and iterating through all elements of a row from left to right before going to the leftmost element of the next row.
    
    Specified by:
    
    walkInRowOrder in interface RealMatrix
    
    Parameters:
    visitor - visitor used to process all matrix entries
    startRow - Initial row index
    endRow - Final row index (inclusive)
    startColumn - Initial column index
    endColumn - Final column index
    
    Returns:
    the value returned by RealMatrixChangingVisitor.end() at the end of the walk
    
    Throws:
    
    OutOfRangeException - if the indices are not valid.
    
    NumberIsTooSmallException - if endRow < startRow or endColumn < startColumn.
    See Also:
    RealMatrix.walkInRowOrder(RealMatrixChangingVisitor), RealMatrix.walkInRowOrder(RealMatrixPreservingVisitor), RealMatrix.walkInRowOrder(RealMatrixPreservingVisitor, int, int, int, int), RealMatrix.walkInColumnOrder(RealMatrixChangingVisitor), RealMatrix.walkInColumnOrder(RealMatrixPreservingVisitor), RealMatrix.walkInColumnOrder(RealMatrixChangingVisitor, int, int, int, int), RealMatrix.walkInColumnOrder(RealMatrixPreservingVisitor, int, int, int, int), RealMatrix.walkInOptimizedOrder(RealMatrixChangingVisitor), RealMatrix.walkInOptimizedOrder(RealMatrixPreservingVisitor), RealMatrix.walkInOptimizedOrder(RealMatrixChangingVisitor, int, int, int, int), RealMatrix.walkInOptimizedOrder(RealMatrixPreservingVisitor, int, int, int, int)
  - walkInRowOrder
```
public double walkInRowOrder(RealMatrixPreservingVisitor visitor,
                    int startRow,
                    int endRow,
                    int startColumn,
                    int endColumn)
                      throws OutOfRangeException,
                             NumberIsTooSmallException
```
    Visit (but don't change) some matrix entries in row order.
    Row order starts at upper left and iterating through all elements of a row from left to right before going to the leftmost element of the next row.
    
    Specified by:
    
    walkInRowOrder in interface RealMatrix
    
    Parameters:
    visitor - visitor used to process all matrix entries
    startRow - Initial row index
    endRow - Final row index (inclusive)
    startColumn - Initial column index
    endColumn - Final column index
    
    Returns:
    the value returned by RealMatrixPreservingVisitor.end() at the end of the walk
    
    Throws:
    
    OutOfRangeException - if the indices are not valid.
    
    NumberIsTooSmallException - if endRow < startRow or endColumn < startColumn.
    See Also:
    RealMatrix.walkInRowOrder(RealMatrixChangingVisitor), RealMatrix.walkInRowOrder(RealMatrixPreservingVisitor), RealMatrix.walkInRowOrder(RealMatrixChangingVisitor, int, int, int, int), RealMatrix.walkInColumnOrder(RealMatrixChangingVisitor), RealMatrix.walkInColumnOrder(RealMatrixPreservingVisitor), RealMatrix.walkInColumnOrder(RealMatrixChangingVisitor, int, int, int, int), RealMatrix.walkInColumnOrder(RealMatrixPreservingVisitor, int, int, int, int), RealMatrix.walkInOptimizedOrder(RealMatrixChangingVisitor), RealMatrix.walkInOptimizedOrder(RealMatrixPreservingVisitor), RealMatrix.walkInOptimizedOrder(RealMatrixChangingVisitor, int, int, int, int), RealMatrix.walkInOptimizedOrder(RealMatrixPreservingVisitor, int, int, int, int)
  - walkInColumnOrder
```
public double walkInColumnOrder(RealMatrixChangingVisitor visitor)
```
    Visit (and possibly change) all matrix entries in column order.
    Column order starts at upper left and iterating through all elements of a column from top to bottom before going to the topmost element of the next column.
    
    Specified by:
    
    walkInColumnOrder in interface RealMatrix
    
    Parameters:
    visitor - visitor used to process all matrix entries
    
    Returns:
    the value returned by RealMatrixChangingVisitor.end() at the end of the walk
    See Also:
    RealMatrix.walkInRowOrder(RealMatrixChangingVisitor), RealMatrix.walkInRowOrder(RealMatrixPreservingVisitor), RealMatrix.walkInRowOrder(RealMatrixChangingVisitor, int, int, int, int), RealMatrix.walkInRowOrder(RealMatrixPreservingVisitor, int, int, int, int), RealMatrix.walkInColumnOrder(RealMatrixPreservingVisitor), RealMatrix.walkInColumnOrder(RealMatrixChangingVisitor, int, int, int, int), RealMatrix.walkInColumnOrder(RealMatrixPreservingVisitor, int, int, int, int), RealMatrix.walkInOptimizedOrder(RealMatrixChangingVisitor), RealMatrix.walkInOptimizedOrder(RealMatrixPreservingVisitor), RealMatrix.walkInOptimizedOrder(RealMatrixChangingVisitor, int, int, int, int), RealMatrix.walkInOptimizedOrder(RealMatrixPreservingVisitor, int, int, int, int)
  - walkInColumnOrder
```
public double walkInColumnOrder(RealMatrixPreservingVisitor visitor)
```
    Visit (but don't change) all matrix entries in column order.
    Column order starts at upper left and iterating through all elements of a column from top to bottom before going to the topmost element of the next column.
    
    Specified by:
    
    walkInColumnOrder in interface RealMatrix
    
    Parameters:
    visitor - visitor used to process all matrix entries
    
    Returns:
    the value returned by RealMatrixPreservingVisitor.end() at the end of the walk
    See Also:
    RealMatrix.walkInRowOrder(RealMatrixChangingVisitor), RealMatrix.walkInRowOrder(RealMatrixPreservingVisitor), RealMatrix.walkInRowOrder(RealMatrixChangingVisitor, int, int, int, int), RealMatrix.walkInRowOrder(RealMatrixPreservingVisitor, int, int, int, int), RealMatrix.walkInColumnOrder(RealMatrixChangingVisitor), RealMatrix.walkInColumnOrder(RealMatrixChangingVisitor, int, int, int, int), RealMatrix.walkInColumnOrder(RealMatrixPreservingVisitor, int, int, int, int), RealMatrix.walkInOptimizedOrder(RealMatrixChangingVisitor), RealMatrix.walkInOptimizedOrder(RealMatrixPreservingVisitor), RealMatrix.walkInOptimizedOrder(RealMatrixChangingVisitor, int, int, int, int), RealMatrix.walkInOptimizedOrder(RealMatrixPreservingVisitor, int, int, int, int)
  - walkInColumnOrder
```
public double walkInColumnOrder(RealMatrixChangingVisitor visitor,
                       int startRow,
                       int endRow,
                       int startColumn,
                       int endColumn)
                         throws OutOfRangeException,
                                NumberIsTooSmallException
```
    Visit (and possibly change) some matrix entries in column order.
    Column order starts at upper left and iterating through all elements of a column from top to bottom before going to the topmost element of the next column.
    
    Specified by:
    
    walkInColumnOrder in interface RealMatrix
    
    Parameters:
    visitor - visitor used to process all matrix entries
    startRow - Initial row index
    endRow - Final row index (inclusive)
    startColumn - Initial column index
    endColumn - Final column index
    
    Returns:
    the value returned by RealMatrixChangingVisitor.end() at the end of the walk
    
    Throws:
    
    OutOfRangeException - if the indices are not valid.
    
    NumberIsTooSmallException - if endRow < startRow or endColumn < startColumn.
    See Also:
    RealMatrix.walkInRowOrder(RealMatrixChangingVisitor), RealMatrix.walkInRowOrder(RealMatrixPreservingVisitor), RealMatrix.walkInRowOrder(RealMatrixChangingVisitor, int, int, int, int), RealMatrix.walkInRowOrder(RealMatrixPreservingVisitor, int, int, int, int), RealMatrix.walkInColumnOrder(RealMatrixChangingVisitor), RealMatrix.walkInColumnOrder(RealMatrixPreservingVisitor), RealMatrix.walkInColumnOrder(RealMatrixPreservingVisitor, int, int, int, int), RealMatrix.walkInOptimizedOrder(RealMatrixChangingVisitor), RealMatrix.walkInOptimizedOrder(RealMatrixPreservingVisitor), RealMatrix.walkInOptimizedOrder(RealMatrixChangingVisitor, int, int, int, int), RealMatrix.walkInOptimizedOrder(RealMatrixPreservingVisitor, int, int, int, int)
  - walkInColumnOrder
```
public double walkInColumnOrder(RealMatrixPreservingVisitor visitor,
                       int startRow,
                       int endRow,
                       int startColumn,
                       int endColumn)
                         throws OutOfRangeException,
                                NumberIsTooSmallException
```
    Visit (but don't change) some matrix entries in column order.
    Column order starts at upper left and iterating through all elements of a column from top to bottom before going to the topmost element of the next column.
    
    Specified by:
    
    walkInColumnOrder in interface RealMatrix
    
    Parameters:
    visitor - visitor used to process all matrix entries
    startRow - Initial row index
    endRow - Final row index (inclusive)
    startColumn - Initial column index
    endColumn - Final column index
    
    Returns:
    the value returned by RealMatrixPreservingVisitor.end() at the end of the walk
    
    Throws:
    
    OutOfRangeException - if the indices are not valid.
    
    NumberIsTooSmallException - if endRow < startRow or endColumn < startColumn.
    See Also:
    RealMatrix.walkInRowOrder(RealMatrixChangingVisitor), RealMatrix.walkInRowOrder(RealMatrixPreservingVisitor), RealMatrix.walkInRowOrder(RealMatrixChangingVisitor, int, int, int, int), RealMatrix.walkInRowOrder(RealMatrixPreservingVisitor, int, int, int, int), RealMatrix.walkInColumnOrder(RealMatrixChangingVisitor), RealMatrix.walkInColumnOrder(RealMatrixPreservingVisitor), RealMatrix.walkInColumnOrder(RealMatrixChangingVisitor, int, int, int, int), RealMatrix.walkInOptimizedOrder(RealMatrixChangingVisitor), RealMatrix.walkInOptimizedOrder(RealMatrixPreservingVisitor), RealMatrix.walkInOptimizedOrder(RealMatrixChangingVisitor, int, int, int, int), RealMatrix.walkInOptimizedOrder(RealMatrixPreservingVisitor, int, int, int, int)
  - walkInOptimizedOrder
```
public double walkInOptimizedOrder(RealMatrixChangingVisitor visitor)
```
    Visit (and possibly change) all matrix entries using the fastest possible order.
    The fastest walking order depends on the exact matrix class. It may be different from traditional row or column orders.
    
    Specified by:
    
    walkInOptimizedOrder in interface RealMatrix
    
    Parameters:
    visitor - visitor used to process all matrix entries
    
    Returns:
    the value returned by RealMatrixChangingVisitor.end() at the end of the walk
    See Also:
    RealMatrix.walkInRowOrder(RealMatrixChangingVisitor), RealMatrix.walkInRowOrder(RealMatrixPreservingVisitor), RealMatrix.walkInRowOrder(RealMatrixChangingVisitor, int, int, int, int), RealMatrix.walkInRowOrder(RealMatrixPreservingVisitor, int, int, int, int), RealMatrix.walkInColumnOrder(RealMatrixChangingVisitor), RealMatrix.walkInColumnOrder(RealMatrixPreservingVisitor), RealMatrix.walkInColumnOrder(RealMatrixChangingVisitor, int, int, int, int), RealMatrix.walkInColumnOrder(RealMatrixPreservingVisitor, int, int, int, int), RealMatrix.walkInOptimizedOrder(RealMatrixPreservingVisitor), RealMatrix.walkInOptimizedOrder(RealMatrixChangingVisitor, int, int, int, int), RealMatrix.walkInOptimizedOrder(RealMatrixPreservingVisitor, int, int, int, int)
  - walkInOptimizedOrder
```
public double walkInOptimizedOrder(RealMatrixPreservingVisitor visitor)
```
    Visit (but don't change) all matrix entries using the fastest possible order.
    The fastest walking order depends on the exact matrix class. It may be different from traditional row or column orders.
    
    Specified by:
    
    walkInOptimizedOrder in interface RealMatrix
    
    Parameters:
    visitor - visitor used to process all matrix entries
    
    Returns:
    the value returned by RealMatrixPreservingVisitor.end() at the end of the walk
    See Also:
    RealMatrix.walkInRowOrder(RealMatrixChangingVisitor), RealMatrix.walkInRowOrder(RealMatrixPreservingVisitor), RealMatrix.walkInRowOrder(RealMatrixChangingVisitor, int, int, int, int), RealMatrix.walkInRowOrder(RealMatrixPreservingVisitor, int, int, int, int), RealMatrix.walkInColumnOrder(RealMatrixChangingVisitor), RealMatrix.walkInColumnOrder(RealMatrixPreservingVisitor), RealMatrix.walkInColumnOrder(RealMatrixChangingVisitor, int, int, int, int), RealMatrix.walkInColumnOrder(RealMatrixPreservingVisitor, int, int, int, int), RealMatrix.walkInOptimizedOrder(RealMatrixChangingVisitor), RealMatrix.walkInOptimizedOrder(RealMatrixChangingVisitor, int, int, int, int), RealMatrix.walkInOptimizedOrder(RealMatrixPreservingVisitor, int, int, int, int)
  - walkInOptimizedOrder
```
public double walkInOptimizedOrder(RealMatrixChangingVisitor visitor,
                          int startRow,
                          int endRow,
                          int startColumn,
                          int endColumn)
                            throws OutOfRangeException,
                                   NumberIsTooSmallException
```
    Visit (and possibly change) some matrix entries using the fastest possible order.
    The fastest walking order depends on the exact matrix class. It may be different from traditional row or column orders.
    
    Specified by:
    
    walkInOptimizedOrder in interface RealMatrix
    
    Parameters:
    visitor - visitor used to process all matrix entries
    startRow - Initial row index
    endRow - Final row index (inclusive)
    startColumn - Initial column index
    endColumn - Final column index (inclusive)
    
    Returns:
    the value returned by RealMatrixChangingVisitor.end() at the end of the walk
    
    Throws:
    
    OutOfRangeException - if the indices are not valid.
    
    NumberIsTooSmallException - if endRow < startRow or endColumn < startColumn.
    See Also:
    RealMatrix.walkInRowOrder(RealMatrixChangingVisitor), RealMatrix.walkInRowOrder(RealMatrixPreservingVisitor), RealMatrix.walkInRowOrder(RealMatrixChangingVisitor, int, int, int, int), RealMatrix.walkInRowOrder(RealMatrixPreservingVisitor, int, int, int, int), RealMatrix.walkInColumnOrder(RealMatrixChangingVisitor), RealMatrix.walkInColumnOrder(RealMatrixPreservingVisitor), RealMatrix.walkInColumnOrder(RealMatrixChangingVisitor, int, int, int, int), RealMatrix.walkInColumnOrder(RealMatrixPreservingVisitor, int, int, int, int), RealMatrix.walkInOptimizedOrder(RealMatrixChangingVisitor), RealMatrix.walkInOptimizedOrder(RealMatrixPreservingVisitor), RealMatrix.walkInOptimizedOrder(RealMatrixPreservingVisitor, int, int, int, int)
  - walkInOptimizedOrder
```
public double walkInOptimizedOrder(RealMatrixPreservingVisitor visitor,
                          int startRow,
                          int endRow,
                          int startColumn,
                          int endColumn)
                            throws OutOfRangeException,
                                   NumberIsTooSmallException
```
    Visit (but don't change) some matrix entries using the fastest possible order.
    The fastest walking order depends on the exact matrix class. It may be different from traditional row or column orders.
    
    Specified by:
    
    walkInOptimizedOrder in interface RealMatrix
    
    Parameters:
    visitor - visitor used to process all matrix entries
    startRow - Initial row index
    endRow - Final row index (inclusive)
    startColumn - Initial column index
    endColumn - Final column index (inclusive)
    
    Returns:
    the value returned by RealMatrixPreservingVisitor.end() at the end of the walk
    
    Throws:
    
    OutOfRangeException - if the indices are not valid.
    
    NumberIsTooSmallException - if endRow < startRow or endColumn < startColumn.
    See Also:
    RealMatrix.walkInRowOrder(RealMatrixChangingVisitor), RealMatrix.walkInRowOrder(RealMatrixPreservingVisitor), RealMatrix.walkInRowOrder(RealMatrixChangingVisitor, int, int, int, int), RealMatrix.walkInRowOrder(RealMatrixPreservingVisitor, int, int, int, int), RealMatrix.walkInColumnOrder(RealMatrixChangingVisitor), RealMatrix.walkInColumnOrder(RealMatrixPreservingVisitor), RealMatrix.walkInColumnOrder(RealMatrixChangingVisitor, int, int, int, int), RealMatrix.walkInColumnOrder(RealMatrixPreservingVisitor, int, int, int, int), RealMatrix.walkInOptimizedOrder(RealMatrixChangingVisitor), RealMatrix.walkInOptimizedOrder(RealMatrixPreservingVisitor), RealMatrix.walkInOptimizedOrder(RealMatrixChangingVisitor, int, int, int, int)
  - toString
```
public String toString()
```
    Get a string representation for this matrix.
    
    Overrides:
    
    toString in class Object
    
    Returns:
    a string representation for this matrix
  - equals
```
public boolean equals(Object object)
```
    Returns true iff object is a RealMatrix instance with the same dimensions as this and all corresponding matrix entries are equal.
    
    Overrides:
    
    equals in class Object
    
    Parameters:
    object - the object to test equality against.
    
    Returns:
    true if object equals this
  - hashCode
```
public int hashCode()
```
    Computes a hashcode for the matrix.
    
    Overrides:
    
    hashCode in class Object
    
    Returns:
    hashcode for matrix
  - createMatrix
```
public abstract RealMatrix createMatrix(int rowDimension,
                      int columnDimension)
                                 throws NotStrictlyPositiveException
```
    Create a new RealMatrix of the same type as the instance with the supplied row and column dimensions.
    
    Specified by:
    
    createMatrix in interface RealMatrix
    
    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:
    
    NotStrictlyPositiveException - if row or column dimension is not positive.
  - copy
```
public abstract RealMatrix copy()
```
    Returns a (deep) copy of this.
    
    Specified by:
    
    copy in interface RealMatrix
    
    Returns:
    matrix copy
  - getEntry
```
public abstract 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
    
    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 abstract void setEntry(int row,
            int column,
            double value)
                       throws OutOfRangeException
```
    Set the entry in the specified row and column. Row and column indices start at 0.
    
    Specified by:
    
    setEntry in interface RealMatrix
    
    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:
    
    OutOfRangeException - if the row or column index is not valid

Class AbstractRealMatrix

Constructor Summary

Method Summary

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

Methods inherited from class java.lang.Object

Constructor Detail

AbstractRealMatrix

AbstractRealMatrix

Method Detail

add

subtract

scalarAdd

scalarMultiply

multiply

preMultiply

power

getData

getNorm

getFrobeniusNorm

getSubMatrix

getSubMatrix

copySubMatrix

copySubMatrix

setSubMatrix

getRowMatrix

setRowMatrix

getColumnMatrix

setColumnMatrix

getRowVector

setRowVector

getColumnVector

setColumnVector

getRow

setRow

getColumn

setColumn

addToEntry

multiplyEntry

transpose

isSquare

getRowDimension

getColumnDimension

getTrace

operate

operate

preMultiply

preMultiply

walkInRowOrder

walkInRowOrder

walkInRowOrder

walkInRowOrder

walkInColumnOrder

walkInColumnOrder

walkInColumnOrder

walkInColumnOrder

walkInOptimizedOrder

walkInOptimizedOrder

walkInOptimizedOrder

walkInOptimizedOrder

toString

equals

hashCode

createMatrix

copy

getEntry

setEntry