ds.granules.util

Class Matrix

java.lang.Object

ds.granules.util.Matrix

Direct Known Subclasses:

MatrixColumnMajor

public class Matrix
extends Object

A class that encapsulates a Matrix. Utility methods are provided to read/write matrices that have elements of different data types.

Author:

Shrideep Pallickara

Field Summary

Fields

Modifier and Type	Field and Description
static int	INT_ENTRIES
static int	LONG_ENTRIES

Constructor Summary

Constructors

Constructor and Description
Matrix(String filename)
Matrix(String filename, int numberOfRows, int numberOfColumns, boolean rowFormat, int entriesType)

Method Summary

Methods

Modifier and Type	Method and Description
int[]	createDenseIntColumn(int numberOfRows)
int[]	createDenseIntRow()
int	getEntriesType()
int	getMetadataLength()
int	getNumberOfColumns()
int	getNumberOfRows()
boolean	isColumnMajorFormat()
boolean	isRowMajorFormat()
static void	main(String[] args)
int[][]	readIntMatrix() Read a matrix that has been written to a file (specified in the constructor) based on the specified rows and columns.
int[]	readIntMatrixColumn(int columnId) This method reads a specified column from the matrix that has been written to a file.
int	readIntMatrixElement(int rowId, int columnId) Reads a matrix element from the underlying file based on the specified [rowId, columId].
int[]	readIntMatrixRow(int rowId) This method reads the specified row of a matrix that has been written to a file.
long[][]	readLongMatrix() Read a matrix that has been written to a file (specified in the constructor) based on the specified rows and columns.
long[]	readLongMatrixColumn(int columnId) This method reads a specified column from the matrix that has been written to a file.
long	readLongMatrixElement(int rowId, int columnId) Reads a matrix element from the underlying file based on the specified [rowId, columId].
long[]	readLongMatrixRow(int rowId) This method reads the specified row of a matrix that has been written to a file.
long	size()
void	writeIntMatrixColumn(int columnId, int[] columnValues) Write a column of the matrix to the underlying file.
void	writeIntMatrixElement(int rowId, int columnId, int value) Write a specific matrix element code>[rowId, columnId] to the file.
void	writeIntMatrixRow(int rowId, int[] rowValues) Write a row of the matrix to the underlying file.
void	writeLongMatrixColumn(int columnId, long[] columnValues) Write a column of the matrix to the underlying file.
void	writeLongMatrixElement(int rowId, int columnId, long value) Write a specific matrix element code>[rowId, columnId] to the file.
void	writeLongMatrixRow(int rowId, long[] rowValues) Write a row of the matrix to the underlying file.

Methods inherited from class java.lang.Object

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

Field Detail

INT_ENTRIES

public static final int INT_ENTRIES

See Also:

Constant Field Values

LONG_ENTRIES

public static final int LONG_ENTRIES

See Also:

Constant Field Values

Constructor Detail

Matrix

public Matrix(String filename,
      int numberOfRows,
      int numberOfColumns,
      boolean rowFormat,
      int entriesType)
       throws IOException

Throws:

IOException

Matrix

public Matrix(String filename)
       throws IOException

Throws:

IOException

Method Detail

size

public long size()
          throws IOException

Throws:

IOException

getMetadataLength

public int getMetadataLength()

isRowMajorFormat

public boolean isRowMajorFormat()

isColumnMajorFormat

public boolean isColumnMajorFormat()

getNumberOfRows

public int getNumberOfRows()

getNumberOfColumns

public int getNumberOfColumns()

getEntriesType

public int getEntriesType()

readLongMatrixRow

public long[] readLongMatrixRow(int rowId)
                         throws IOException

This method reads the specified row of a matrix that has been written to a file. This method also requires the number of columns to be specified.

Parameters:

rowId - The matrix row that needs to be retrieved

Throws:

IOException - If there are problems locating the file or reading its contents.

readLongMatrixColumn

public long[] readLongMatrixColumn(int columnId)
                            throws IOException

This method reads a specified column from the matrix that has been written to a file. This method also requires the number of matrix rows to be specified.

Parameters:

columnId - The matrix column that needs to be retrieved

Returns:

The column[] in question

Throws:

IOException - If there are problems locating the file or reading its contents.

readLongMatrixElement

public long readLongMatrixElement(int rowId,
                         int columnId)
                           throws IOException

Reads a matrix element from the underlying file based on the specified [rowId, columId].

Parameters:

rowId - The rowId for the matrix element

columnId - The columnId for the matrix element

Returns:

the value of the matrix[rowId, columnId] element.

Throws:

IOException - If there are problems reading the file.

readLongMatrix

public long[][] readLongMatrix()
                        throws IOException

Read a matrix that has been written to a file (specified in the constructor) based on the specified rows and columns. Depending on the size of the matrix, trying to read the entire matrix can lead to OutOfMemoryError

Returns:

The long[][] matrix

Throws:

IOException - If there are problems reading from the file.

writeLongMatrixElement

public void writeLongMatrixElement(int rowId,
                          int columnId,
                          long value)
                            throws IOException

Write a specific matrix element code>[rowId, columnId] to the file.

Parameters:

rowId - The row identifier for the element

columnId - The column identifier for the element

value - The value of the matrix element [rowId, columnId]

Throws:

IOException - If there are problems writing to the file.

writeLongMatrixRow

public void writeLongMatrixRow(int rowId,
                      long[] rowValues)
                        throws IOException

Write a row of the matrix to the underlying file.

Parameters:

rowId - The identifier of the matrix row

rowValues - The values associated with the row

Throws:

IOException - If there are problems writing to the file.

writeLongMatrixColumn

public void writeLongMatrixColumn(int columnId,
                         long[] columnValues)
                           throws IOException

Write a column of the matrix to the underlying file.

Parameters:

columnId - The columnId for the matrix column

columnValues - Values associated with the column

Throws:

IOException - If there are problems writing to the file.

readIntMatrixRow

public int[] readIntMatrixRow(int rowId)
                       throws IOException

This method reads the specified row of a matrix that has been written to a file. This method also requires the number of columns to be specified.

Parameters:

rowId - The matrix row that needs to be retrieved

Throws:

IOException - If there are problems locating the file or reading its contents.

readIntMatrixColumn

public int[] readIntMatrixColumn(int columnId)
                          throws IOException

This method reads a specified column from the matrix that has been written to a file. This method also requires the number of matrix rows to be specified.

Parameters:

columnId - The matrix column that needs to be retrieved

Returns:

The column[] in question

Throws:

IOException - If there are problems locating the file or reading its contents.

readIntMatrixElement

public int readIntMatrixElement(int rowId,
                       int columnId)
                         throws IOException

Reads a matrix element from the underlying file based on the specified [rowId, columId].

Parameters:

rowId - The rowId for the matrix element

columnId - The columnId for the matrix element

Returns:

the value of the matrix[rowId, columnId] element.

Throws:

IOException - If there are problems reading the file.

readIntMatrix

public int[][] readIntMatrix()
                      throws IOException

Read a matrix that has been written to a file (specified in the constructor) based on the specified rows and columns. Depending on the size of the matrix, trying to read the entire matrix can lead to OutOfMemoryError

Returns:

The matrix[][]

Throws:

IOException - If there are problems reading from the file.

writeIntMatrixElement

public void writeIntMatrixElement(int rowId,
                         int columnId,
                         int value)
                           throws IOException

Write a specific matrix element code>[rowId, columnId] to the file.

Parameters:

rowId - The row identifier for the element

columnId - The column identifier for the element

value - The value of the matrix element [rowId, columnId]

Throws:

IOException - If there are problems writing to the file.

writeIntMatrixRow

public void writeIntMatrixRow(int rowId,
                     int[] rowValues)
                       throws IOException

Write a row of the matrix to the underlying file.

Parameters:

rowId - The identifier of the matrix row

rowValues - The values associated with the row

Throws:

IOException - If there are problems writing to the file.

writeIntMatrixColumn

public void writeIntMatrixColumn(int columnId,
                        int[] columnValues)
                          throws IOException

Write a column of the matrix to the underlying file.

Parameters:

columnId - The columnId for the matrix column

columnValues - Values associated with the column

Throws:

IOException - If there are problems writing to the file.

createDenseIntRow

public int[] createDenseIntRow()

createDenseIntColumn

public int[] createDenseIntColumn(int numberOfRows)

main

public static void main(String[] args)

Parameters:

args -