Files
QuanTAlib/Calculations/_Updated/ZSCORE_Series.cs
T

91 lines
3.3 KiB
C#

using System.Linq;
namespace QuanTAlib;
using System;
using System.Collections.Generic;
/* <summary>
ZSCORE: number of standard deviations from SMA
Z-score describes a value's relationship to the mean of a series, as measured in
terms of standard deviations from the mean. If a Z-score is 0, it indicates that
the data point's score is identical to the mean score. A Z-score of 1.0 would
indicate a value that is one standard deviation from the mean. Z-scores may be
positive or negative, with a positive value indicating the score is above the
mean and a negative score indicating it is below the mean.
Sources:
https://en.wikipedia.org/wiki/Z-score
https://www.investopedia.com/terms/z/zscore.asp
Calculation:
std = std * STDEV(close, length)
mean = SMA(close, length)
ZSCORE = (close - mean) / std
</summary> */
public class ZSCORE_Series : TSeries {
private readonly System.Collections.Generic.List<double> _buffer = new();
protected readonly int _period;
protected readonly bool _NaN;
protected readonly TSeries _data;
//core constructors
public ZSCORE_Series(int period, bool useNaN) : base() {
_period = period;
_NaN = useNaN;
Name = $"ZSCORE({period})";
}
public ZSCORE_Series(TSeries source, int period, bool useNaN) : this(period, useNaN) {
_data = source;
Name = Name.Substring(0, Name.IndexOf(")")) + $", {(string.IsNullOrEmpty(_data.Name) ? "data" : _data.Name)})";
_data.Pub += Sub;
Add(_data);
}
public ZSCORE_Series() : this(period: 0, useNaN: false) { }
public ZSCORE_Series(int period) : this(period: period, useNaN: false) { }
public ZSCORE_Series(TBars source) : this(source.Close, 0, false) { }
public ZSCORE_Series(TBars source, int period) : this(source.Close, period, false) { }
public ZSCORE_Series(TBars source, int period, bool useNaN) : this(source.Close, period, useNaN) { }
public ZSCORE_Series(TSeries source) : this(source, 0, false) { }
public ZSCORE_Series(TSeries source, int period) : this(source: source, period: period, useNaN: false) { }
//////////////////
// core Add() algo
public override (DateTime t, double v) Add((DateTime t, double v) TValue, bool update = false) {
BufferTrim(buffer:_buffer, value:TValue.v, period:_period, update: 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);
double _zscore = (_psdev == 0) ? 1 : (TValue.v - _sma) / _psdev;
var res = (TValue.t, Count < _period - 1 && _NaN ? double.NaN : _zscore);
return base.Add(res, update);
}
public override (DateTime t, double v) Add(TSeries data) {
if (data == null) { return (DateTime.Today, Double.NaN); }
foreach (var item in data) { Add(item, false); }
return _data.Last;
}
public new (DateTime t, double v) Add((DateTime t, double v) TValue) {
return Add(TValue, false);
}
public (DateTime t, double v) Add(bool update) {
return this.Add(TValue: _data.Last, update: update);
}
public (DateTime t, double v) Add() {
return Add(TValue: _data.Last, update: false);
}
private new void Sub(object source, TSeriesEventArgs e) {
Add(TValue: _data.Last, update: e.update);
}
//reset calculation
public override void Reset() {
_buffer.Clear();
}
}