Public Sub RemoveCustomFunction( _
   ByVal name As String _
) 

Dim instance As DefaultSheetDataModel
Dim name As String
 
instance.RemoveCustomFunction(name)

public void RemoveCustomFunction( 
   string name
)

<Serializable()>
    public class CubeFunctionInfo : FarPoint.CalcEngine.FunctionInfo 
    { 
        public override string Name { get { return "CUBE"; } } 
        public override int MinArgs { get { return 1; } } 
        public override int MaxArgs { get { return 1; } } 
        public override object Evaluate (object[] args) 
        { 
            double num = FarPoint.CalcEngine.CalcConvert.ToDouble(args[0]); 
            return num * num * num; 
        } 
    }
<Serializable()>
public class MultiFunc : FarPoint.CalcEngine.FunctionInfo 
    { 
      public override string Name { get { return "MULTI"; } } 
      public override int MinArgs { get { return 1; } } 
      public override int MaxArgs { get { return 1; } } 
      public override object Evaluate (object[] args) 
      { 
        double num = FarPoint.CalcEngine.CalcConvert.ToDouble(args[0]); 
        return num * num; 
      } 
    } 
    
private void PageLoad(object sender, System.EventArgs e)
{
    FarPoint.Web.Spread.Model.DefaultSheetDataModel dataModel = new FarPoint.Web.Spread.Model.DefaultSheetDataModel(5, 5); 
    System.Collections.IEnumerator se; 
    dataModel.AddCustomFunction(new CubeFunctionInfo()); 
    dataModel.AddCustomFunction(new MultiFunc()); 
    FpSpread1.ActiveSheetView.SetFormula(1, 1, "CUBE(4)"); 
    FpSpread1.ActiveSheetView.SetFormula(2, 2, "MULTI(10)"); 
    FpSpread1.ActiveSheetView.DataModel = dataModel; 
    dataModel.RemoveCustomFunction("CUBE")
    dataModel.Recalculate();    
}

<Serializable()> 
Public Class CubeFunctionInfo
   Inherits FarPoint.CalcEngine.FunctionInfo

   Public Overrides ReadOnly Property Name() As String
      Get
         Return "CUBE"
      End Get
   End Property

   Public Overrides ReadOnly Property MinArgs() As Integer
      Get
         Return 1
      End Get
   End Property

   Public Overrides ReadOnly Property MaxArgs() As Integer
      Get
         Return 1
      End Get
   End Property

   Public Overrides Function Evaluate(ByVal args() As Object) As Object
   Dim num As Double = FarPoint.CalcEngine.CalcConvert.ToDouble(args(0))
      Return num * num * num
   End Function

End Class

<Serializable()> 
Public Class MultiFunc
Inherits FarPoint.CalcEngine.FunctionInfo

Public Overrides ReadOnly Property Name() As String
   Get
   Return "MULTI"
   End Get
   End Property

   Public Overrides ReadOnly Property MinArgs() As Integer
   Get
   Return 1
   End Get
   End Property

   Public Overrides ReadOnly Property MaxArgs() As Integer
   Get
   Return 1
   End Get
   End Property

   Public Overrides Function Evaluate(ByVal args() As Object) As Object
   Dim num As Double = FarPoint.CalcEngine.CalcConvert.ToDouble(args(0))
   Return num * num
   End Function
End Class


Private Sub PageLoad(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
Dim dataModel As New FarPoint.Web.Spread.Model.DefaultSheetDataModel(5, 5)
Dim se As System.Collections.IEnumerator
dataModel.AddCustomFunction(New CubeFunctionInfo)
dataModel.AddCustomFunction(New MultiFunc)
FpSpread1.ActiveSheetView.SetFormula(1, 1, "CUBE(4)")
FpSpread1.ActiveSheetView.SetFormula(2, 2, "MULTI(10)")

FpSpread1.ActiveSheetView.DataModel = dataModel

dataModel.RemoveCustomFunction("CUBE")
dataModel.Recalculate()
End Sub