structure
Class Matrix

java.lang.Object
  |
  +--structure.Matrix

public class Matrix

extends Object

An implementation of rectangular vectors. This implementation of a Matrix is minimal. Few operations are provided, and no support for mathematical operations is considered.

Example Usage:

 public static void main(String[] argv){
	//create an array of arrays to bet copied into the matrix
	int[][] test = new int[][]{new int[]{1,2,3},
				   new int[]{4,5,6}, 
				   new int[]{7,8,9}};

	//create the matrix
	Matrix testMatrix = new Matrix(test.length, test[0].length);
	
	//copy the 2-d array into the matrix
	for(int i = 0; i < test.length; i++){
	    for(int j = 0; j < test[0].length; j++){
		testMatrix.set(i,j,new Integer(test[i][j]));
	    }
	}

	//print out the matrix
	System.out.println(testMatrix);
  }
 

Field Summary

protected int	height
protected Vector	rows
protected int	width

Constructor Summary

Matrix()
Construct an empty matrix.

Matrix(int h, int w)
Constructs a matrix such that all values are null.

Method Summary

void	addCol(int c) Add a new column, whose index will be c.
void	addRow(int r) Add a new row, whose index will be r.
Object	get(int row, int col) Fetch an element from the matrix.
int	height() Return the height of the matrix.
Vector	removeCol(int c) Remove a column, whose index is c.
Vector	removeRow(int r) Remove the row whose index is r.
void	set(int row, int col, Object value) Change the value at location (row, col)
String	toString() Construct a string representation of the matrix.
int	width() Return the width of the matrix.

Methods inherited from class java.lang.Object

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

Field Detail

height

protected int height

width

protected int width

rows

protected Vector rows

Constructor Detail

Matrix

public Matrix()

Construct an empty matrix.

Matrix

public Matrix(int h,
              int w)

Constructs a matrix such that all values are null.

Parameters:

h - Height of the matrix.

w - Width of the matrix.

Method Detail

get

public Object get(int row,
                  int col)

Fetch an element from the matrix.

Parameters:

row - The row of the element

col - The column of the element

Precondition:

0 <= row < height(), 0 <= col < width()

Postcondition:

returns object at (row, col)

Returns:

Object located at matrix position (row, col)

set

public void set(int row,
                int col,
                Object value)

Change the value at location (row, col)

Parameters:

value - The new Object reference (possibly null).

row - The row of the value to be changed.

col - The column of the value to be changed.

Precondition:

0 <= row < height(), 0 <= col < width()

Postcondition:

changes location (row, col) to value

addRow

public void addRow(int r)

Add a new row, whose index will be r.

Parameters:

r - The index of the newly inserted row.

Precondition:

0 <= r < height()

Postcondition:

inserts row of null values to be row r

addCol

public void addCol(int c)

Add a new column, whose index will be c.

Parameters:

c - The index of the newly inserted column.

Precondition:

0 <= c < width()

Postcondition:

inserts column of null values to be column c

removeRow

public Vector removeRow(int r)

Remove the row whose index is r. The row is returned as a vector.

Parameters:

r - The index of the to-be-removed row.

Precondition:

0 <= r < height()

Postcondition:

removes row r and returns it as a Vector

Returns:

A vector of values once in the row.

removeCol

public Vector removeCol(int c)

Remove a column, whose index is c.

Parameters:

c - The index of the column to be removed.

Precondition:

0 <= c < width

Postcondition:

removes column c and returns it as a vector

Returns:

A vector of the values removed.

width

public int width()

Return the width of the matrix.

Postcondition:

returns number of columns in matrix

Returns:

The number of columns in the matrix.

height

public int height()

Return the height of the matrix.

Postcondition:

returns number of rows in matrix

Returns:

The number of rows in the matrix.

toString

public String toString()

Construct a string representation of the matrix.

Overrides:

toString in class Object

Postcondition:

returns string description of matrix.

Returns:

A string, representing the matrix.