IIndicatorsiDonchian Method

Function iDonchian ( 
	sessionIndex As Integer,
	symbol As String,
	timeframe As TimeFrame,
	mode As DonchianMode,
	Optional lookbackPeriods As Integer = 20
) As List(Of Double?)

List<Nullable<double>>^ iDonchian(
	int sessionIndex, 
	String^ symbol, 
	TimeFrame timeframe, 
	DonchianMode mode, 
	int lookbackPeriods = 20
)

abstract iDonchian : 
        sessionIndex : int * 
        symbol : string * 
        timeframe : TimeFrame * 
        mode : DonchianMode * 
        ?lookbackPeriods : int 
(* Defaults:
        let _lookbackPeriods = defaultArg lookbackPeriods 20
*)
-> List<Nullable<float>>