All Packages  Class Hierarchy  This Package  Previous  Next  Index

Class structure.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.

Constructor Index

o Matrix()
Construct an empty matrix.
o Matrix(int, int)
Constructs a matrix such that all values are null.

Method Index

o elementAt(int, int)
Fetch an element from the matrix.
o height()
Return the height of the matrix.
o insertColAt(int)
Add a new column, whose index will be c.
o insertRowAt(int)
Add a new row, whose index will be r.
o removeColAt(int)
Remove a column, whose index is c.
o removeRowAt(int)
Remove the row whose index is r.
o setElementAt(Object, int, int)
Change the value at location (row, col)
Precondition:
0 <= row < height(), 0 <= col < width()
Postcondition:
changes location (row,col) to value
o toString()
Construct a string representation of the matrix.
o width()
Return the width of the matrix.

Constructors

o Matrix 
 public Matrix()
Construct an empty matrix.

Postcondition:
constructs empty matrix

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

Precondition:
h >= 0, w >= 0;
Postcondition:
constructs an h row by w column matrix

Parameters:
h - Height of the matrix.
w - Width of the matrix.

Methods

o elementAt 
 public Object elementAt(int row,
                         int col)
Fetch an element from the matrix.
Precondition:
0 <= row < height(), 0 <= col < width()
Postcondition:
returns object at (row, col)

Parameters:
row - The row of the element
col - The column of the element
o setElementAt 
 public void setElementAt(Object value,
                          int row,
                          int col)
Change the value at location (row, col)
Precondition:
0 <= row < height(), 0 <= col < width()
Postcondition:
changes location (row,col) to value

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.
o insertRowAt 
 public void insertRowAt(int r)
Add a new row, whose index will be r.

Precondition:
0 <= r <= height()
Postcondition:
inserts row of null values to be row r

Parameters:
r - The index of the newly inserted row.
o insertColAt 
 public void insertColAt(int c)
Add a new column, whose index will be c.

Precondition:
0 <= c <= width()
Postcondition:
inserts column of null values to be column c

Parameters:
c - The index of the newly inserted column.
o removeRowAt 
 public Vector removeRowAt(int r)
Remove the row whose index is r. The row is returned as a vector.
Precondition:
0 <= r < height()
Postcondition:
removes row r and returns it as a Vector.

Parameters:
r - The index of the to-be-removed row.
Returns:
A vector of values once in the row.
o removeColAt 
 public Vector removeColAt(int c)
Remove a column, whose index is c.
Precondition:
0 <= c < width
Postcondition:
removes column c and returns it as a vector

Parameters:
c - The index of the column to be removed.
Returns:
A vector of the values removed.
o 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.
o 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.
o toString 
 public String toString()
Construct a string representation of the matrix.
Postcondition:
returns string description of matrix.

Returns:
A string, representing the matrix.
Overrides:
toString in class Object 
All Packages  Class Hierarchy  This Package  Previous  Next  Index