structure
Class Matrix

java.lang.Object
  structure.Matrix

public class Matrix
extends java.lang.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.

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.
java.lang.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, java.lang.Object value) Change the value at location (row, col)
java.lang.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, 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.

Postcondition:

constructs 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.

Precondition:

h >= 0, w >= 0;

Postcondition:

constructs an h row by w column matrix

Method Detail

get

public java.lang.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

Returns:

Object located at matrix position (row, col)

Precondition:

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

Postcondition:

returns object at (row, col)

set

public void set(int row,
                int col,
                java.lang.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.

Returns:

A vector of values once in the row.

Precondition:

0 <= r < height()

Postcondition:

removes row r and returns it as a Vector

removeCol

public Vector removeCol(int c)

Remove a column, whose index is c.

Parameters:

c - The index of the column to be removed.

Returns:

A vector of the values removed.

Precondition:

0 <= c < width()

Postcondition:

removes column c and returns it as a vector

width

public int width()

Return the width of the matrix.

Returns:

The number of columns in the matrix.

Postcondition:

returns number of columns in matrix

height

public int height()

Return the height of the matrix.

Returns:

The number of rows in the matrix.

Postcondition:

returns number of rows in matrix

toString

public java.lang.String toString()

Construct a string representation of the matrix.

Overrides:

toString in class java.lang.Object

Returns:

A string, representing the matrix.

Postcondition:

returns string description of matrix.