Refactoring the structure, upgrading to .NET 6.0/7.0/8.0

Calculations/Statistics/SDEV_Series.cs

@@ -0,0 +1,39 @@
+namespace QuanTAlib;
+using System;
+using System.Linq;
+
+/* <summary>
+SDEV: Population Standard Deviation
+  Population Standard Deviation is the square root of the biased variance, also knons as
+  Uncorrected Sample Standard Deviation
+
+Sources:
+  https://en.wikipedia.org/wiki/Standard_deviation#Uncorrected_sample_standard_deviation
+
+Remark:
+  SDEV (Population Standard Deviation) is also known as a biased/uncorrected Standard Deviation.
+  For unbiased version that uses Bessel's correction, use SDEV instead.
+    
+</summary> */
+
+public class SDEV_Series : Single_TSeries_Indicator
+{
+    public SDEV_Series(TSeries source, int period, bool useNaN = false) : base(source, period, useNaN)
+    {
+        if (base._data.Count > 0) { base.Add(base._data); }
+    }
+    private readonly System.Collections.Generic.List<double> _buffer = new();
+
+    public override void Add((System.DateTime t, double v) TValue, bool update)
+    {
+        Add_Replace_Trim(_buffer, TValue.v, _p, update);
+        double _sma = _buffer.Average();
+
+        double _pvar = 0;
+        for (int i = 0; i < _buffer.Count; i++) { _pvar += (_buffer[i] - _sma) * (_buffer[i] - _sma); }
+        _pvar /= this._buffer.Count;
+        double _psdev = Math.Sqrt(_pvar);
+
+        base.Add((TValue.t, _psdev), update, _NaN);
+    }
+}