ADL with tests

Source/Indicators/ADL_Series.cs

@@ -0,0 +1,43 @@
+namespace QuanTAlib;
+using System;
+
+/* <summary>
+ADL: Chaikin Accumulation/Distribution Line
+    ADL is a volume-based indicator that measures the cumulative Money Flow Volume:
+
+    1. Money Flow Multiplier = [(Close  -  Low) - (High - Close)] /(High - Low) 
+    2. Money Flow Volume = Money Flow Multiplier x Volume for the Period
+    3. ADL = Previous ADL + Current Period's Money Flow Volume
+
+Sources:
+    https://school.stockcharts.com/doku.php?id=technical_indicators:accumulation_distribution_line
+
+</summary> */
+
+public class ADL_Series : Single_TBars_Indicator
+{
+	private double _lastadl, _lastlastadl;
+
+	public ADL_Series(TBars source, bool useNaN = false) : base(source, 0, useNaN)
+	{
+		this._lastadl = this._lastlastadl = 0;
+		if (_bars.Count > 0)
+		{ base.Add(_bars); }
+	}
+
+	public override void Add((DateTime t, double o, double h, double l, double c, double v) TBar, bool update)
+	{
+		if (update)
+		{ this._lastadl = this._lastlastadl; }
+
+		double _mfm = ((TBar.c - TBar.l) - (TBar.h - TBar.c)) / (TBar.h - TBar.l);
+		double _mfv = _mfm * TBar.v;
+		double _adl = this._lastadl + _mfv;
+
+		this._lastlastadl = this._lastadl;
+		this._lastadl = _adl;
+
+		var ret = (TBar.t, this.Count < this._p - 1 && this._NaN ? double.NaN : _adl);
+		base.Add(ret, update);
+	}
+}