Syntax
public FractalDown(DataSeries ds, string description)
public static FractalDown Series(DataSeries ds)
Parameter Description
  
    | ds | Any DataSeries.  Typically pass Bars.Low | 
Description
Fractals per Bill Williams in 'Trading Chaos, Second Edition' are an indication of a change in market direction/behavior.  An up (or buy) fractal is a minimum of 5-bar pattern where the center bar's low is less than the low of the two bars on either side of it. FractalDown returns the value of the most recent down/sell fractal as of the current bar.
See also: 
FractalDownBar, 
FractalUpBar, 
FractalUp, 
AlligatorInterpretation
A fractal "sell" occurs when price crosses below a down/sell fractal if it is below the 
Alligator teeth at the time of the crossing.  You can use fractal sell signals to sell long positions and/or to add short positions.
Example
The example plots the FractalUp and 
FractalDown Series and also uses the 
FractalUpBar and 
FractalDownBar indicators to annotate the fractal bars. 
using System;
using System.Collections.Generic;
using System.Text;
using System.Drawing;
using WealthLab;
using WealthLab.Indicators;
using Community.Indicators;
namespace WealthLab.Strategies
{
	public class ShowFractalDemo : WealthScript
	{
		public void ShowFractals(DataSeries fractalupbars, DataSeries fractaludnbars)
		{			
			Font _wing = new Font("Wingdings", 11, FontStyle.Bold);
			string _upFractal = Convert.ToChar(0x00D9).ToString();
			string _dnFractal = Convert.ToChar(0x00DA).ToString();
									
			for(int n = 5; n < fractalupbars.Count; n++)
			{								
				if (fractalupbarsn > fractalupbarsn-1)
				{
					int fbar = (int)fractalupbarsn;
					AnnotateBar(_upFractal, fbar, true, Color.Silver, Color.Transparent, _wing);
				}
				
				if (fractaludnbarsn > fractaludnbarsn-1)
				{
					int fbar = (int)fractaludnbarsn;
					AnnotateBar(_dnFractal, fbar, false, Color.Silver, Color.Transparent, _wing);
				}
			}
		}
		
		protected override void Execute()
		{
			
			/* Fractals */
			DataSeries frUpBar = FractalUpBar.Series(High);
			DataSeries frDnBar = FractalDownBar.Series(Low);
			ShowFractals(frUpBar, frDnBar);
			
			
			DataSeries frUp = FractalUp.Series(High);
			DataSeries frDn = FractalDown.Series(Low);
			PlotSeries(PricePane, frUp, Color.Blue, LineStyle.Dots, 3);
			PlotSeries(PricePane, frDn, Color.Fuchsia, LineStyle.Dots, 3);
			
		}
	}
}