Need to Pre-load DataSeries?

[Crassius]

I have been thinking about DataSeries as arrays. One thing I am not sure of, is what they contain... 0 or Null, or what... if we have not loaded anything into them yet..

Here is a snippet of code from NinjaTrader_Ray...

protected override void OnBarUpdate()
{
if(CurrentBar < 6)
return;

diff.Set(Median[0] - Median[6]);

double mid = diff[3];
double wtd = 0.75 * (diff[0] - diff[6]) + 0.25 * (diff[2] - diff[4]);

diff is a DataSeries, and on the seven bar, he loads (sets) a value into diff[0].... but a few lines later he accesses diff[6], diff[4], diff[2] and does some math with their values.

What do diff[2], diff[4] and diff[6] contain on the first pass through this code, on the close of the 7th bar?

I have been pre-loading something in mine to make sure something is there.... maybe I don't have to?

[koganam]

I believe that is what NT calls the unstable part of the indicator?

One thing will be to dump out the values using Print() statements and see what they contain. I would venture to say they are probably zero, as it would appear that diff is not defined before bar 6, so that diff[6] on bar 6 cannot be defined either as that would be diff on bar 0. It is probably not double.MinValue.

[NinjaTrader_Bertrand]

Crassius, they would hold 0 values - we generally advise to not attempt to access a dataseries value for a bar where you would not have called the Set() method for as you could run into exceptions - in the example case it's fine as you would not access those bars used to initialize the code.

[Crassius]

Thanks for the clarification.