1: using System;
 2:
 3: // class represents a 2 " 2 matrix
 4: class Matrix{
 5:
 6:   // these 4 fields represent the 4 values in the 2 " 2 matrix
 7:   public float TopLeft;
 8:   public float TopRight;
 9:   public float BottomLeft;
10:   public float BottomRight;
11:
12:   // constructor
13:   public Matrix
14:   (float TopLeft, float TopRight, float BottomLeft, float BottomRight){
15:     this.TopLeft = TopLeft;
16:     this.TopRight = TopRight;
17:     this.BottomLeft = BottomLeft;
18:     this.BottomRight = BottomRight;
19:   }
20:
21:   // overrides ToString to show matrix values
22:   public override string ToString (){
23:     return "[" + TopLeft + ", " + TopRight + "]
"+
24:            "[" + BottomLeft+ ", " + BottomRight+ "]";
25:   }
26:
27:   // overloads + operator to perform matrix addition
28:   public static Matrix operator + (Matrix m1, Matrix m2){
29:     return new Matrix(m1.TopLeft + m2.TopLeft,
30:                       m1.TopRight + m2.TopRight,
31:                       m1.BottomLeft + m2.BottomLeft,
32:                       m1.BottomRight + m2.BottomRight);
33:   }
34:
35:   // overloads – operator to perform matrix subtraction
36:   public static Matrix operator – (Matrix m1, Matrix m2){
37:     return new Matrix(m1.TopLeft – m2.TopLeft,
38:                       m1.TopRight – m2.TopRight,
39:                       m1.BottomLeft – m2.BottomLeft,
40:                       m1.BottomRight – m2.BottomRight);
41:   }
42:
43:   // overloads * operator to perform product with a real number
44:   public static Matrix operator * (Matrix m1, float realNumber){
45:     return new Matrix(m1.TopLeft * realNumber,
46:                       m1.TopRight * realNumber,
47:                       m1.BottomLeft * realNumber,
48:                       m1.BottomRight * realNumber);
49:   }
50:
51:   // overloads ^ to perform multiplication with another 2 " 2 matrix
52:   public static Matrix operator ^ (Matrix m1, Matrix m2){
53:     return new Matrix
54:       ((m1.TopLeft * m2.TopLeft) + (m1.TopRight * m2.BottomLeft),
55:       (m1.TopLeft * m2.TopRight) + (m1.TopRight * m2.BottomRight),
56:       (m1.BottomLeft * m2.TopLeft) + (m1.BottomRight * m2.BottomLeft),
57:       (m1.BottomLeft * m2.TopRight) + (m1.BottomRight * m2.BottomRight)
58:       );
59:   }
60:
61:   // overloads ! operator to perform matrix inversion.
62:   public static Matrix operator ! (Matrix m1){
63:
64:     float determinant =
65:       (m1.TopLeft * m1.BottomRight) – (m1.TopRight * m1.BottomLeft);
66:
67:     float determinantReciprocal = 1/determinant;
68:
69:     Matrix intermediate = new Matrix
70:       (m1.BottomRight, -m1.TopRight, -m1.BottomLeft, m1.TopLeft);
71:
72:     return (intermediate * determinantReciprocal);
73:    }
74: }
75:
76:
77: class TestClass{
78:   public static void Main(){
79:
80:     // try out inverse function
81:       Matrix m1 = new Matrix (3,5,1,2);
82:     Console.WriteLine ("m1:
" + m1);
83:     Console.WriteLine ("m1 inverse:
" + (!m1));
84:     Console.WriteLine ();
85:
86:     // try out multiplication with a real number
87:       Matrix m2 = new Matrix (1,5,5,1);
88:     Console.WriteLine ("m2:
" + m2);
89:     Console.WriteLine ("3 multiplied by m2:
" + (m2*3));
90:   }
91: }

c:expt>test
m1:
[3 , 5]
[1 , 2]
m1 inverse:
[2 , -5]
[-1 , 3]
m2:
[1 , 5]
[5 , 1]
3 multiplied by m2:
[3 , 15]
[15 , 3]