Untitled

Private Function GetMatrixInput(rows As Integer, columns As Integer) As Double(,)
    Dim matrix(rows - 1, columns - 1) As Double

    For i As Integer = 0 To rows - 1
        For j As Integer = 0 To columns - 1
            Dim textBoxName As String = "arr" & i & j
            Dim textBox As TextBox = Me.Controls(textBoxName)

            Dim value As Double
            If Double.TryParse(textBox.Text, value) Then
                matrix(i, j) = value
            Else
                MessageBox.Show("Invalid input in arr" & i & j & ". Please enter valid integers.")
                Return Nothing ' or handle error as needed
            End If
        Next
    Next

    Return matrix
End Function
Private Sub BtnCalculate_Click(sender As Object, e As EventArgs) Handles BtnCalculate.Click
    ' Assuming the matrix is a square matrix (n = rows = columns)
    Dim n As Integer = 3 ' Example: For a 3x3 matrix
    Dim matrix(n - 1, n - 1) As Double

    matrix = GetMatrixInput(n, n)

    If matrix IsNot Nothing Then
        ' Calculate determinant
        Dim determinant As Double = Det(matrix)

        ' Display the result in a designated textbox
        result.Text = determinant.ToString()
    Else
        ' Handle the case where there was an error in input
        result.Text = "Error in input. Please check values."
    End If
End Sub
Function Minor(a As Double(,), x As Integer, y As Integer) As Double(,)
    Dim length = a.GetLength(0) - 1
    Dim result(length - 1, length - 1) As Double
    For i = 1 To length
        For j = 1 To length
            If i < x AndAlso j < y Then
                result(i - 1, j - 1) = a(i - 1, j - 1)
            ElseIf i >= x AndAlso j < y Then
                result(i - 1, j - 1) = a(i, j - 1)
            ElseIf i < x AndAlso j >= y Then
                result(i - 1, j - 1) = a(i - 1, j)
            Else
                result(i - 1, j - 1) = a(i, j)
            End If
        Next
    Next
    Return result
End Function
Function Det(a As Double(,)) As Double
    If a.GetLength(0) = 1 Then
        Return a(0, 0)
    Else
        Dim sign = 1
        Dim sum = 0.0
        For i = 1 To a.GetLength(0)
            sum += sign * a(0, i - 1) * Det(Minor(a, 0, i))
            sign *= -1
        Next
        Return sum
    End If
End Function