Setting DataSeries to the previous value

[freewind]

Hi,

I'm using a DataSeries that sometimes I need to set the current value to the previous one.
For example:

protected override void OnBarUpdate()
{
     ....
    dataSeries.Set(dataSeries[0]); //dataSeries.Set(dataSeries[1]);
     ...
}

My question is to what barAgo value I need to refer [0] or [1]?

TX!

[NinjaTrader_Bertrand]

freewind, you would set it then to the previous one so barindex [1].