Narrow Range indicator

using System;
using cAlgo.API;
using cAlgo.API.Collections;
using cAlgo.API.Indicators;
using cAlgo.API.Internals;

namespace cAlgo
{
    [Levels(0,1)]
    [Indicator(IsOverlay = false, TimeZone = TimeZones.UTC, AccessRights = AccessRights.None)]
    public class mNarrowRange : Indicator
    {
        [Parameter("Period (4|7)", DefaultValue = 7)]
        public int inpPeriod { get; set; }
    
        [Output("NarrowRange", LineColor = "Black", PlotType = PlotType.Histogram, Thickness = 4)]
        public IndicatorDataSeries outNR { get; set; }
        
        private IndicatorDataSeries _range, _minrange;
        

        protected override void Initialize()
        {
            _range = CreateDataSeries();
            _minrange = CreateDataSeries();
        }

        public override void Calculate(int i)
        {
            _range[i] = Bars.HighPrices[i] - Bars.LowPrices[i];
            _minrange[i] = _range.Minimum(inpPeriod);
             
            outNR[i] = _range[i] < _minrange[i-1] ? +1 : 0;
        }
    }
}