Indicator Error on calling 'OnBarUpdate' : Index was outside the bounds of the array.

[nicthe]

I am currently struggling to understand BarCount, CurrentBars and a general strategy to understand when a my data is safe to read / write. Can someone help me out? I have tried adding sanity checks as described in the docs / here but I am still running into errors.

> Indicator 'SpikeVolume': Error on calling 'OnBarUpdate' method on bar 5: Index was outside the bounds of the array.

using NinjaTrader.NinjaScript.Indicators.Nic;
using System.Windows.Media;
using Nic.Utilities;
using System.ComponentModel.DataAnnotations;
using System.ComponentModel;
using System.Xml.Serialization;

namespace NinjaTrader.NinjaScript.Indicators.Nic
{
    public class SpikeVolume : Indicator
    {
        [Range(1, int.MaxValue), NinjaScriptProperty]
        [Display(ResourceType = typeof(Custom.Resource), Order = 0)]
        public int Period { get; set; }
        [Range(1, int.MaxValue), NinjaScriptProperty]
        [Display(ResourceType = typeof(Custom.Resource), Order = 1)]
        public int MinPeriod { get; set; }
        [Range(1, int.MaxValue), NinjaScriptProperty]
        [Display(ResourceType = typeof(Custom.Resource), Order = 2)]
        public double SigmaThreshold { get; set; }
        [Range(1, int.MaxValue), NinjaScriptProperty]
        [Display(ResourceType = typeof(Custom.Resource), Order = 3)]
        public double SigmaThreshold2 { get; set; }

        [Browsable(false)]
        [XmlIgnore()]
        public Series<double> Volume1 { get { return Values[0]; } }
        [Browsable(false)]
        [XmlIgnore()]
        public Series<double> Volume2 { get { return Values[1]; } }
        [Browsable(false)]
        [XmlIgnore()]
        public Series<double> Volume3 { get { return Values[2]; } }

        private StdDevCalc _stdDevEth;
        private StdDevCalc _stdDevRth;

        protected override void OnStateChange()
        {
            if (State == State.SetDefaults)
            {
                Description = @"Nic Spike Volume";
                Name = "Nic Spike Volume";
                Calculate = Calculate.OnEachTick;
                BarsRequiredToPlot = 0;
                IsAutoScale = false;
                IsOverlay = false;
                DrawOnPricePanel = false;

                Period = 50;
                MinPeriod = 10;
                SigmaThreshold = 2;
                SigmaThreshold2 = 3;
            }
            else if(State == State.SetDefaults)
            {
                AddPlot(Brushes.DarkGray, "Volume");
                AddPlot(Brushes.LightYellow, "Volume Sigma 1");
                AddPlot(Brushes.Yellow, "Volume Sigma 2");
            }
            else if (State == State.Configure)
            {

            }
            else if (State == State.DataLoaded)
            {
                _stdDevEth = new StdDevCalc(Period);
                _stdDevRth = new StdDevCalc(Period);
            }
        }

        protected override void OnBarUpdate()
        {
            base.OnBarUpdate();

             // Attempted Fix Here !
            if (CurrentBars[0] < 5 || CurrentBars[1] < 5 || CurrentBars[2] < 5 || CurrentBars[3] < 5) return;
            if (CurrentBar < 2) return;

            var stdDev = this.IsRTH()  ? _stdDevRth : _stdDevEth;

            if (IsFirstTickOfBar)
            {
                stdDev.Update(Volume[1]);
            }

            var volume = Volume[0];

            if (stdDev.Count() < MinPeriod)
            {
                // FAILS HERE !
                Volume1[0] = volume;
                return;
            }

            var sigma = stdDev.Average();

            if (volume >= sigma * SigmaThreshold2)
            {
                Volume3[0] = volume;
            }
            else if (volume >= sigma * SigmaThreshold)
            {
                Volume2[0] = volume;
            }
            else
            {
                Volume1[0] = volume;
            }
        }
    }
}&#8203; 

[nicthe]

User error. My mistake was here using `else if(State == State.SetDefaults)` twice.