Custom indicator values change when "Days to load" changes

[fredb987]

Hello,

I've been experimenting with a custom indicator I found on the site a while back called "SpreadZScore". Please see attached code.

Here is the problem I'm seeing and how it can be replicated: Load this indicator onto a 5 minute chart with say, 10 days of data. Take note of the last printed value of the indicator. Now modify the chart's data series to show 20 days of data. Look at the last printed indicator value again... it will be different than what you saw on the 10 day chart.

I believe there is a problem with the way the DataSeries is set up, but I can't figure out how to correct this.

Thanks in advance for any assistance with this. I see some great potential in this indicator but need to know it shows consistent values regardless of the size of the chart.

Fred

[NinjaTrader_RyanM1]

Hi fredb987,

This is not an NT provided indicator so unfortunately we won't be able to provide much insight on expected behavior. Best may be to PM the author directly with your observations.

[koganam]

Hello,

I've been experimenting with a custom indicator I found on the site a while back called "SpreadZScore". Please see attached code.

Here is the problem I'm seeing and how it can be replicated: Load this indicator onto a 5 minute chart with say, 10 days of data. Take note of the last printed value of the indicator. Now modify the chart's data series to show 20 days of data. Look at the last printed indicator value again... it will be different than what you saw on the 10 day chart.

I believe there is a problem with the way the DataSeries is set up, but I can't figure out how to correct this.

Thanks in advance for any assistance with this. I see some great potential in this indicator but need to know it shows consistent values regardless of the size of the chart.

Fred

I do not even get that far. I tried it with /TF as the main instrument, and ^SP500 as the hedge on a 5 minute time frame. I get the error: "Error on calling 'OnBarUpdate' method for indicator 'SpreadZScore' on bar 0: You are accessing an index with a value that is invalid since its out of range. I.E. accessing a series [barsAgo] with a value of 5 when there are only 4 bars on the chart."

You might want to call on the author to correct his script, as this is one that has been posted for sharing.

[fredb987]

Solved

This additional code at the beginning of OnBarUpdate seems to correct the problem:

protected override void OnBarUpdate() /////////////////////////////////////////////
        {
			if (BarsInProgress != 0)
				return;
			
			if (CurrentBar == 0)
			{
				zPlot.Set(0);
				mySpread.Set(0);
				Value.Set(0);
			}
			else
				
			if (CurrentBars[0] < zPeriod || CurrentBars[1] < zPeriod)
        		return;
		
			//Calculate spread

...