Calcul de la matrice inverse (code qui marche ! ) :: par souhail & safae ::

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Contenu du snippet

ce code permet de retourner la matrice inverse d'une matrice donnée en paramètre en utilisant la méthode des déterminant.

Source / Exemple : 


Public Sub Inverse(ma() As Double, mb() As Double, Erreur As Boolean)
Dim m1() As Double, m2() As Double, d As Double
ReDim m1(UBound(ma, 1), UBound(ma, 2))
ReDim m2(UBound(ma, 1), UBound(ma, 2))
If ((Not (UBound(ma, 1) = UBound(ma, 2))) Or (Determinant(ma, UBound(ma, 1)) = 0)) Then
                                Erreur = True
Else
    d = (1 / Determinant(ma, UBound(ma, 1)))
    Transpose ma, m2
    Coffacteur m2, m1
    ProduitScalaire d, m1, mb
    Erreur = False
End If
End Sub

Public Sub ProduitScalaire(a As Double, ma() As Double, mb() As Double)
Dim i As Integer, j As Integer
ReDim mb(UBound(ma, 1), UBound(ma, 2))
For i = 0 To (UBound(ma, 1) - 1)
  For j = 0 To (UBound(ma, 2) - 1)
    mb(i, j) = ma(i, j) * a
  Next
Next
End Sub

Public Sub Det_aux(ma() As Double, mb() As Double, l As Integer, c As Integer)
Dim i As Integer, j As Integer, d As Integer, E As Integer
  E = 0
  ReDim mb(UBound(ma, 1) - 1, UBound(ma, 2) - 1)
  For i = 0 To (UBound(ma, 1) - 1)
   d = 0
    If (i <> l) Then
                  For j = 0 To (UBound(ma, 2) - 1)
                    If (j <> c) Then
                                  mb(E, d) = ma(i, j)
                                  d = d + 1
                                End If
                  Next
                   E = E + 1
                End If
  Next
End Sub

Public Function Expo(n As Integer) As Double
   If ((n Mod 2) = 0) Then
                        Expo = 1
                      Else
                        Expo = -1
   End If
End Function

Public Function Determinant(m() As Double, l As Integer) As Double
Dim i As Integer, j As Integer, ii As Integer, jj As Integer
Dim m2() As Double, X As Double, Y As Double

X = 0
If (l = 2) Then
            Determinant = (m(0, 0) * m(1, 1)) - (m(0, 1) * m(1, 0))
          Else
            For i = 0 To (l - 1)
               Det_aux m, m2, 0, i
               Y = Determinant(m2, (l - 1))
               X = X + (Expo(i) * m(0, i) * Y)
            Next
            Determinant = X
End If
End Function

Public Sub Coffacteur(MatD() As Double, MatR() As Double)
Dim i As Integer, j As Integer, Temp() As Double, Det As Double
ReDim MatR(UBound(MatD, 1), UBound(MatD, 2))
If ((UBound(MatD, 1) = 2) And (UBound(MatD, 1) = 2)) Then
            MatR(0, 0) = Expo(0) * (MatD(1, 1))
            MatR(0, 1) = Expo(1) * (MatD(0, 1))
            MatR(1, 0) = Expo(1) * (MatD(1, 0))
            MatR(1, 1) = Expo(0) * (MatD(0, 0))
Else
     For i = 0 To (UBound(MatD, 1) - 1)
        For j = 0 To (UBound(MatD, 2) - 1)
            Det_aux MatD, Temp, i, j
            MatR(i, j) = Expo(i + j) * Determinant(Temp, UBound(Temp, 1))
        Next
    Next
End If
End Sub

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