How-to-get-and-display-data-for-a-different-instrument-scale

You created a "new BarHistory" but didn't assign anything to it.

See the QuickRef examples for the Classes:
- BarHistoryCompressor
- BarHistorySynchronize
- TimeSeriesCompressor
- TimeSeriesSynchronize

Also, if you're really looking for a "different instrument" (not just the scale), see GetHistory() method in the UserStrategyBase class.

I can't create an indicator using this technology. In strategy, this technology works. I've also noticed that when I make some kind of error while creating the indicators, no obvious compilation error is output. However, it is not possible to compile. My goal is to create an indicator that would show the value of the EMA on a larger time frame.

Please explain to me how to write this indicator and tell me how I can understand (except in practice) which technologies work in indicators and which only in strategies, since this is not the first time I have encountered a difference in the availability of functionality in indicators and strategies.

A more general idea is to write an indicator that could show the values ​​of any other indicators on a different time scale. And so that it can be used in the strategy builder.

CODE:

using WealthLab.Core;
using System;
using System.Drawing;
using WealthLab.Indicators; 

namespace WealthLab.MyIndicators
{
    public class Ema_greater_scale : IndicatorBase
    {
        //parameterless constructor
        public Ema_greater_scale() : base()
        {
        }

        //for code based construction
        public Ema_greater_scale(BarHistory source, Int32 compressionperiod, Int32 emaperiod)
            : base()
        {
         Parameters[0].Value = source;
         Parameters[1].Value = compressionperiod;
         Parameters[2].Value = emaperiod;

            Populate();
        }

      //static Series method
      public static Ema_greater_scale Series(BarHistory source, Int32 compressionperiod, Int32 emaperiod)
      {
         return new Ema_greater_scale(source, compressionperiod, emaperiod);
      }

        //name
        public override string Name
        {
            get
            {
                return "EMA_Greater_Scale";
            }
        }

        //abbreviation
        public override string Abbreviation
        {
            get
            {
                return "Ema_greater_scale";
            }
        }

        //description
        public override string HelpDescription
        {
            get
            {
                return "";
            }
        }

        //price pane
        public override string PaneTag
        {
            get
            {
                return "Greater_Scale_Pane";
            }
        }

      //default color
      public override WLColor DefaultColor
      {
         get
         {
            return WLColor.FromArgb(255,0,0,255);
         }
      }

      //default plot style
      public override PlotStyle DefaultPlotStyle
      {
         get
         {
            return PlotStyle.Line;
         }
      }

        //populate
        public override void Populate()
        {
         BarHistory source = Parameters[0].AsBarHistory;
         Int32 compressionperiod = Parameters[1].AsInt;
         Int32 period=Parameters[2].AsInt;
         TimeSeries EMACompressedBars;         

         //Compress to ...-hour bars
         BarHistory CompressedBars = BarHistoryCompressor.ToHour(source, compressionperiod);

         //Get a RSI(14) of the ...-hour low series
         EMACompressedBars = EMA.Series(CompressedBars.Close, 14);

         //synchronize the rsi
         EMACompressedBars = TimeSeriesSynchronizer.Synchronize(EMACompressedBars, source.Close);

            DateTimes = source.Close.DateTimes;
            
         //modify the code below to implement your own indicator calculation
            for (int n = 0; n < source.Close.Count; n++)
         {
                Values[n] = EMACompressedBars[n];
         }
        }

        //generate parameters
        protected override void GenerateParameters()
        {
         AddParameter("Source", ParameterType.BarHistory, null);
         AddParameter("CompressionPeriod", ParameterType.Int32, 1);
         AddParameter("EMAPeriod", ParameterType.Int32, 20);

        }
    }
}