RealMatrix
org.apache.commons.math3.linear

## Interface RealMatrix

• ### 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.
`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.
`RealMatrix` ```createMatrix(int rowDimension, int columnDimension)```
Create a new RealMatrix of the same type as the instance with the supplied row and column dimensions.
`double[]` `getColumn(int column)`
Get the entries at the given column index as an array.
`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.
`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.
`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).
`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 `v`.
`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`.
`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`.
`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 interface org.apache.commons.math3.linear.AnyMatrix

`getColumnDimension, getRowDimension, isSquare`