Visual Basic

<AttributeUsage(AttributeTargets.Field, AllowMultiple:=False, Inherited:=False)> _
Public Class OutputDescriptionAttribute
    Inherits Attribute

#Region "Variables"
    Private _oldDescription As String
    Private _newDescription As String
#End Region

#Region "Properties"
    Public ReadOnly Property OldDescription As String
        Get
            Return Me._oldDescription
        End Get
    End Property

    Public ReadOnly Property NewDescription As String
        Get
            Return Me._newDescription
        End Get
    End Property
#End Region

#Region "Constructor"
    Public Sub New(oldDescription As String, newDescription As String)
        Me._oldDescription = oldDescription
        Me._newDescription = newDescription
    End Sub
#End Region

End Class

Public Enum ConditionType
    <OutputDescription("I", "Intact")> Intact
    <OutputDescription("F", "Fair")> Fair
    <OutputDescription("P", "Poor")> Poor
    <OutputDescription("N", "None")> None
End Enum

Private Sub GetAttribute(T As Type)

         Dim attr As OutputDescriptionAttribute = CType(Attribute.GetCustomAttribute(T, GetType(OutputDescriptionAttribute)), OutputDescriptionAttribute)

        Dim newDesc As String = attr.NewDescription
        Dim oldDesc As String = attr.OldDescription
End Sub

Dim condition As ConditionType = ConditionType.Fair
GetAttribute(condition.GetType)

Private Function Identity(value As Double) As Double
       Return value
   End Function

   Private Function [Step](value As Double) As Double
       If value <= 0 Then
           Return 0
       Else
           Return 1
       End If
   End Function

   Private Function LogarithmicSigmoid(value As Double, alpha As Double) As Double
       If value < -45.0 Then
           Return 0
       ElseIf value > 45.0 Then
           Return 1
       Else
           Return (1.0 / (1.0 + Exp(-alpha * value)))
       End If
   End Function

   Private Function SymmetricSigmoid(value As Double) As Double
       Return HyperbolicTangent(value)
   End Function

   Private Function HyperbolicTangent(value As Double) As Double
       If value < -45 Then
           Return -1.0
       ElseIf value > 45.0 Then
           Return 1.0
       Else
           Return Tanh(value)
       End If
   End Function

Public Enum ActivationFunctions
        IDENTITY
        [STEP]
        LOGARITHMIC_SIGMOID
        SYMMETRIC_SIGMOID
        HYPERBOLIC_TANGENT
    End Enum

Private activationFunction As Func(Of Double)

Public Sub SetActivationFunction(activationFunction As ActivationFunctions, value As Double, Optional alpha As Double = 1)
        Select Case activationFunction
            Case ActivationFunctions.IDENTITY
                Me.activationFunction = Function(value As Double) '<---PROBLEM LINE
        End Select
End Sub

Public Sub SetActivationFunction(ByVal activationFunction As Func(Of Double))
        'DON'T KNOW WHAT TO DO HERE
End Sub