Creates the inverse of a matrix and returns a reference to it.

Syntax

MatrixObject.Inverse

Return Value

Returns a matrix object reference to the inverse of the current matrix.

Remarks

Inverse method does not alter the current matrix, rather it creates a new matrix and returns a reference to it.

Matrix inversion is only possible for square matrices.

Error handling is recommended, in order to trap errors that might arise from Inverse method, in case the current matrix is found to be a singular matrix.

Error Codes

Error 1305 will be returned if the matrix is not square.

Error 1306 will be returned if matrix inversion is not possible (i.e. singular matrix).

Example

This example demonstrates the use of the Times and Inverse methods. One matrix is created and then multiplied by its inverse to return the unitary matrix.

Private Sub MatrixInverse()

Dim A As Matrix, B As Matrix, C As Matrix

    'Generate a matrix, fill it with random values
    'and print it in debug window
    Set A = New Matrix
    A.Size 5, 5
    A.FillRandom
    Debug.Print "Matrix A = "
    Debug.Print A.GetString
    
    'Use Inverse method to get its inverse
    On Error Resume Next
    Set B = A.Inverse
    If (Err.Number = (vbObjectError + 1306)) Then
        Debug.Print "Matrix is singular"
        Exit Sub
    End If
    On Error GoTo 0
    Debug.Print "Matrix B = A.Inverse"
    Debug.Print B.GetString
    
    'Now verify the result by forming the product
    ' C = A x B. Matrix C is a unary matrix
    Set C = A.Times(B)
    Debug.Print "C = A x B "
    Debug.Print C.GetString
    
End Sub

Output

Matrix A = 
|  6.000  2.000  8.000  6.000  5.000 |
|  4.000  9.000  8.000  7.000  2.000 |
|  9.000  7.000  5.000  3.000  0.000 |
|  1.000  4.000  1.000  2.000 10.000 |
|  4.000  1.000  0.000  0.000  4.000 |

Matrix B = A.Inverse
| -0.048  0.176 -0.158 -0.235  0.560 |
| -0.076 -0.069  0.198  0.174 -0.305 |
|  0.410 -1.035  1.032  0.847 -2.112 |
| -0.362  1.360 -1.374 -1.112  2.552 |
|  0.067 -0.158  0.108  0.192 -0.233 |

C = A x B 
| 1.000 0.000 0.000 0.000 0.000 |
| 0.000 1.000 0.000 0.000 0.000 |
| 0.000 0.000 1.000 0.000 0.000 |
| 0.000 0.000 0.000 1.000 0.000 |
| 0.000 0.000 0.000 0.000 1.000 |

See Also

Applies To: Matrix | CMatrix