Package org.flag4j.operations.sparse.csr.real

Class RealCsrManipulations

java.lang.Object

org.flag4j.operations.sparse.csr.real.RealCsrManipulations

public class RealCsrManipulations
extends Object

Utility class for manipulating real sparse CSR matrices (e.g. row swaps, column swaps, etc.).

Constructor Summary

Constructors

Modifier	Constructor	Description
private	RealCsrManipulations()

Method Summary

Modifier and Type	Method	Description
private static void	moveAndShiftLeft(CsrMatrix src, int newColIdx, int currPos, int newPos)	Moves a non-zero value in a row of a CSR matrix to a new column to the right of its current column.
private static void	moveAndShiftRight(CsrMatrix src, int newColIdx, int currPos, int newPos)	Moves a non-zero value in a row of a CSR matrix to a new column to the left of its current column.
static void	swapCols(CsrMatrix src, int colIdx1, int colIdx2)	Swaps two columns in a sparse CSR matrix.
static void	swapRows(CsrMatrix src, int rowIdx1, int rowIdx2)	Swaps two rows in a sparse CSR matrix.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Details

RealCsrManipulations

private RealCsrManipulations()

Method Details

swapRows

public static void swapRows(CsrMatrix src,
 int rowIdx1,
 int rowIdx2)

Swaps two rows in a sparse CSR matrix. This is done in place.

Parameters:

src - The matrix to swap rows within, done in place.

rowIdx1 - Index of the first row to swap.

rowIdx2 - Index of the second row to swap.

Throws:

IndexOutOfBoundsException - If either rowIdx1 or rowIdx2 is out of bounds of the rows of this matrix.

swapCols

public static void swapCols(CsrMatrix src,
 int colIdx1,
 int colIdx2)

Swaps two columns in a sparse CSR matrix. This is done in place.

Parameters:

src - The matrix to swap rows within, done in place.

colIdx1 - Index of the first column to swap.

colIdx2 - Index of the second column to swap.

Throws:

IndexOutOfBoundsException - If either colIndex1 or colIndex2 is out of bounds of the columns of this matrix.

moveAndShiftRight

private static void moveAndShiftRight(CsrMatrix src,
 int newColIdx,
 int currPos,
 int newPos)

Moves a non-zero value in a row of a CSR matrix to a new column to the left of its current column. The new column is assumed to contain a zero. To accommodate this move, all entries between the columns are shifted right within the non-zero entries array.

Parameters:

src - Source matrix to perform the move and shift within (modified).

newColIdx - New column for the value to be moved to within the row.

currPos - Current index of the value within the non-zero entries of src (assumed to be in the same row as newPos).

newPos - New index for the value to be moved to within the non-zero entries of src (assumed to be in the same row as currPos).

moveAndShiftLeft

private static void moveAndShiftLeft(CsrMatrix src,
 int newColIdx,
 int currPos,
 int newPos)

Moves a non-zero value in a row of a CSR matrix to a new column to the right of its current column. The new column is assumed to contain a zero. To accommodate this move, all entries between the columns are shifted left within the non-zero entries array.

Parameters:

src - Source matrix to perform the move and shift within (modified).

newColIdx - New column for the value to be moved to within the row.

currPos - Current index of the value within the non-zero entries of src (assumed to be in the same row as newPos).

newPos - New index for the value to be moved to within the non-zero entries of src (assumed to be in the same row as currPos).