LineUtils (Wealth-Lab Framework)

LineUtils is a static class of function that aid with projecting trendlines.

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

namespace WealthScript123
{
	public class GetTroughExample : UserStrategyBase
	{
		PeakTroughCalculator _ptc;

		public override void Initialize(BarHistory bars)
		{
			//control variables
			double swingPct = 8.0;

			//calculate peaks and troughs based on high/lows
			_ptc = new PeakTroughCalculator(bars, swingPct, PeakTroughReversalType.Percent);


			int bar = bars.Count - 1;

			PeakTrough peak1 = _ptc.GetPeak(bar);
			if (peak1 != null)
			{
				DrawDot(peak1.XIndex, peak1.Value, WLColor.Cyan, 6); 
				PeakTrough peak2 = _ptc.GetPeak(peak1.XIndex);
				if (peak2 != null)
				{
					DrawDot(peak2.XIndex, peak2.Value, WLColor.Cyan, 6); 
					bar = bars.Count - 1;
					
					//extend the line created by the two peaks to the last bar
					double y = LineUtils.ExtendLineY(peak1, peak2, bar);
					DrawLine(peak2.XIndex, peak2.YValue, bar, y, WLColor.Cyan, 2);
				}
			}
		}

		public override void Execute(BarHistory bars, int idx)
		{
		}
	}
}

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

namespace WealthScript123
{
	public class ParallelTrendLineDemo : UserStrategyBase
	{
		PeakTroughCalculator _ptc;

		public override void Initialize(BarHistory bars)
		{
			//control variables
			double swingPct = 8.0;

			//calculate peaks and troughs based on high/lows
			_ptc = new PeakTroughCalculator(bars, swingPct, PeakTroughReversalType.Percent);


			int bar = bars.Count - 1;

			PeakTrough peak1 = _ptc.GetPeak(bar);
			if (peak1 != null)
			{
				DrawDot(peak1.XIndex, peak1.Value, WLColor.Cyan, 6); 
				PeakTrough peak2 = _ptc.GetPeak(peak1.XIndex);
				if (peak2 != null)
				{
					DrawDot(peak2.XIndex, peak2.Value, WLColor.Cyan, 6); 
					bar = bars.Count - 1;
					
					//extend the line created by the two peaks to the last bar
					double y = LineUtils.ExtendLineY(peak1, peak2, bar);
					DrawLine(peak2.XIndex, peak2.YValue, bar, y, WLColor.Cyan, 2);

					//create a channel, first find the opposite line
					TrendLine trendline = LineUtils.ParallelTrendLine(bars, peak1, peak2);

					// extend and draw it to the last bar
					y = LineUtils.ExtendLineY(trendline, bar);
					// alternatively for TrendLine:  y = trendline.ExtendTo(bar);
					DrawLine(trendline.Index1, trendline.Value1, bar, y, WLColor.Cyan, 2);
				}
			}
		}

		public override void Execute(BarHistory bars, int idx)
		{
		}
	}
}

using WealthLab.Backtest;
using System;
using WealthLab.Core;
using WealthLab.Data;
using WealthLab.Indicators;
using System.Collections.Generic;

namespace WealthScript2 
{
	public class MyStrategy : UserStrategyBase
	{
		//create indicators and other objects here, this is executed prior to the main trading loop
		public override void Initialize(BarHistory bars)
		{
			// find the range in the recent chart range
			int idx = bars.Count - 1;
			int lookback = Math.Min(250, idx); 
			double H = Highest.Value(idx, bars.High, lookback); 
			double L = Lowest.Value(idx, bars.High, lookback); 

			double pct = 100 * (H / L - 1) / 4.0;
			DrawHeaderText("Percent PeakTroughs: " + pct.ToString("N2"), WLColor.Cyan, 14);
			_ptc = new PeakTroughCalculator(bars, pct, PeakTroughReversalType.Percent);
			
			//find the TrendLine created by the 2 most recent troughs and 
			// then draw a parallel line from the midpoint between the first trough and previous peak
			bool useLog = false;
			TrendLine tL = _ptc.GetLowerTrendLine(idx, 2, useLog);

			// the peak that preceeds the trendline
			PeakTrough peak = _ptc.GetPeak(tL.Index1 - 1); 
			
			// find the midpoint 
			int midX = (peak.XIndex + tL.Index1) / 2;
			double midY = (peak.YValue + tL.Value1) / 2.0;

			DrawDot(midX, midY, WLColor.Blue, 6);
			TrendLine pTL = LineUtils.ParallelTrendLineAt(bars, midX, midY, tL, useLog);
			
			// draw the lines to the last bar
			DrawLine(tL.Index1, tL.Value1, idx, tL.ExtendTo(idx), WLColor.Red, 2);
			DrawLine(midX, midY, idx, pTL.ExtendTo(idx), WLColor.Blue, 2);

		}

		//execute the strategy rules here, this is executed once for each bar in the backtest history
		public override void Execute(BarHistory bars, int idx)
		{
		}

		//declare private variables below
		PeakTroughCalculator _ptc;

	}
}

using WealthLab.Backtest;
using System;
using WealthLab.Core;
using WealthLab.Data;
using WealthLab.Indicators;
using System.Collections.Generic;

namespace WealthScript123
{
    public class TrendLineFromHighsDemo : UserStrategyBase
    {
        //create indicators and other objects here, this is executed prior to the main trading loop
        public override void Initialize(BarHistory bars)
        {
			// draw the Trend from the last 5% peak
			PeakTroughCalculator ptc = new PeakTroughCalculator(bars, 5, PeakTroughReversalType.Percent);
			PeakTrough peak = ptc.GetPeak(bars.Count - 1);			
			int anchorbar = peak.XIndex;
			int bar = bars.Count - 1;

			TrendLine tL = LineUtils.TrendLineFromHighs(bars, bar, anchorbar);
			if (tL != null)
				DrawLine(tL.Index1, bars.High[tL.Index1], bar, tL.ExtendTo(bar, false), WLColor.Blue, 2);
        }

        //execute the strategy rules here, this is executed once for each bar in the backtest history
        public override void Execute(BarHistory bars, int idx)
        {
        }

        //declare private variables below

    }
}

using WealthLab.Backtest;
using System;
using WealthLab.Core;
using WealthLab.Data;
using WealthLab.Indicators;
using System.Collections.Generic;

namespace WealthScript123
{
    public class TrendLineFromLowsDemo : UserStrategyBase
    {
        //create indicators and other objects here, this is executed prior to the main trading loop
        public override void Initialize(BarHistory bars)
        {
			int anchorbar = bars.Low.GetLowestBar(bars.Count - 1, 50);
			int bar = bars.Count - 1;

			TrendLine tL = LineUtils.TrendLineFromLows(bars, bar, anchorbar);
			if (tL != null)
				DrawLine(tL.Index1, bars.Low[tL.Index1], bar, tL.ExtendTo(bar, false), WLColor.Blue, 2);
        }

        //execute the strategy rules here, this is executed once for each bar in the backtest history
        public override void Execute(BarHistory bars, int idx)
        {
        }

        //declare private variables below

    }
}

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

namespace WealthScript2
{
	public class ParallelTrendLineDemo : UserStrategyBase
	{
		PeakTroughCalculator _ptc;

		public override void Initialize(BarHistory bars)
		{
			//control variables
			double swingPct = 8.0;
			bool useLog = false;

			//calculate peaks and troughs based on high/lows
			_ptc = new PeakTroughCalculator(bars, swingPct, PeakTroughReversalType.Percent);


			int bar = bars.Count - 1;

			PeakTrough peak1 = _ptc.GetPeak(bar);
			if (peak1 != null)
			{
				DrawDot(peak1.XIndex, peak1.Value, WLColor.Cyan, 6);
				PeakTrough peak2 = _ptc.GetPeak(peak1.XIndex);
				if (peak2 != null)
				{
					DrawDot(peak2.XIndex, peak2.Value, WLColor.Cyan, 6);
					bar = bars.Count - 1;

					//extend the line created by the two peaks to the last bar
					double y = LineUtils.ExtendLineY(peak1, peak2, bar);
					DrawLine(peak2.XIndex, peak2.YValue, bar, y, WLColor.Cyan, 2);

					//find the opposite line that forms a converging or diverging triangle
					TrendLine trendline = LineUtils.TriangleTrendLine(bars, peak1, peak2, useLog);

					// extend the line and draw it to the last bar
					y = LineUtils.ExtendLineY(trendline, bar, useLog);
					// alternatively for TrendLine:  y = trendline.ExtendTo(bar);
					DrawLine(trendline.Index1, trendline.Value1, bar, y, WLColor.Cyan, 2);
				}
			}
		}

		public override void Execute(BarHistory bars, int idx)
		{
		}
	}
}