Sum function error ninjascript series

[sdauteuil]

I am trying to create a variable that sums N periods of the OrderFlowCumulativeDelta.

but when I try to create a variable(value) using the SUM function
double value = SUM(cumulativeDelta.DeltaClose[0], 2)[0];

I get the error "cannot convert from 'double' to NinjaTrader.NinjaScript.ISeries<double>"


I can use simple logic under OnBarUpdate() like
(cumulativeDelta.DeltaClose[0] + (cumulativeDelta.DeltaClose[1] >0)

I can also set a variable (value)
double value = cumulativeDelta.DeltaClose[0]+cumulativeDelta.DeltaClose[1];



I was able to create a variable "cumualtiveDelta" accessing NT8 OrderFlowCumulativeDelta ** with help from the forum and help guide

namespace NinjaTrader.NinjaScript.Strategies
{
public class TestCumDelta : Strategy
{
private OrderFlowCumulativeDelta cumulativeDelta;
}


I


Any help with the proper syntax to assign the SUM function to a variable would be appreciated

[NinjaTrader_ChelseaB]

Hello sdauteuil,

cumulativeDelta.DeltaClose is a series of doubles (Series<double>).

https://ninjatrader.com/support/helpGuides/nt8/order_flow_cumulative_delta2.htm

cumulativeDelta.DeltaClose[0] uses an index to select the most recent double in this series.

Perhaps remove the index '[0]' to return the series and not the most recent bar's double value?

[sdauteuil]

That worked

Thank you