docs: remove C# Implementation Considerations sections, clean up temp scripts, reorganize test files

- Remove 'C# Implementation Considerations' sections from 34 indicator .md files
- Delete 29 temp PowerShell scripts (_fix_mojibake.ps1, _hex_scan.ps1, etc.)
- Move test files into tests/ subdirectories for consistent project structure
- Add trader-focused bullet points to indicator documentation
This commit is contained in:
Miha Kralj
2026-03-12 12:34:16 -07:00
parent 8937b0c0fa
commit 060649192f
1149 changed files with 1780 additions and 3316 deletions
@@ -0,0 +1,111 @@
using TradingPlatform.BusinessLayer;
using QuanTAlib;
namespace QuanTAlib.Tests;
public sealed class Fisher04IndicatorTests
{
[Fact]
public void Fisher04Indicator_Constructor_SetsDefaults()
{
var indicator = new Fisher04Indicator();
Assert.Equal(10, indicator.Period);
Assert.Equal(SourceType.Close, indicator.Source);
Assert.True(indicator.ShowColdValues);
Assert.Equal("FISHER04 - Ehlers Fisher Transform (2004)", indicator.Name);
Assert.True(indicator.SeparateWindow);
Assert.True(indicator.OnBackGround);
}
[Fact]
public void Fisher04Indicator_MinHistoryDepths_EqualsZero()
{
var indicator = new Fisher04Indicator { Period = 10 };
Assert.Equal(0, Fisher04Indicator.MinHistoryDepths);
IWatchlistIndicator watchlistIndicator = indicator;
Assert.Equal(0, watchlistIndicator.MinHistoryDepths);
}
[Fact]
public void Fisher04Indicator_ShortName_IncludesParameters()
{
var indicator = new Fisher04Indicator { Period = 20 };
indicator.Initialize();
Assert.Contains("Fisher04", indicator.ShortName, StringComparison.Ordinal);
Assert.Contains("20", indicator.ShortName, StringComparison.Ordinal);
}
[Fact]
public void Fisher04Indicator_SourceCodeLink_IsValid()
{
var indicator = new Fisher04Indicator();
Assert.Contains("github.com", indicator.SourceCodeLink, StringComparison.Ordinal);
Assert.Contains("Fisher04.Quantower.cs", indicator.SourceCodeLink, StringComparison.Ordinal);
}
[Fact]
public void Fisher04Indicator_Initialize_CreatesInternalFisher()
{
var indicator = new Fisher04Indicator { Period = 10 };
indicator.Initialize();
Assert.Equal(2, indicator.LinesSeries.Count);
}
[Fact]
public void Fisher04Indicator_ProcessUpdate_HistoricalBar_ComputesValue()
{
var indicator = new Fisher04Indicator { Period = 5 };
indicator.Initialize();
var now = DateTime.UtcNow;
for (int i = 0; i < 20; i++)
{
indicator.HistoricalData.AddBar(now.AddMinutes(i), 100 + i, 110 + i, 90 + i, 105 + i);
var args = new UpdateArgs(UpdateReason.HistoricalBar);
indicator.ProcessUpdate(args);
}
double value = indicator.LinesSeries[0].GetValue(0);
Assert.True(double.IsFinite(value));
}
[Fact]
public void Fisher04Indicator_ProcessUpdate_NewBar_ComputesValue()
{
var indicator = new Fisher04Indicator { Period = 5 };
indicator.Initialize();
var now = DateTime.UtcNow;
for (int i = 0; i < 20; i++)
{
indicator.HistoricalData.AddBar(now.AddMinutes(i), 100 + i, 110 + i, 90 + i, 105 + i);
}
indicator.ProcessUpdate(new UpdateArgs(UpdateReason.HistoricalBar));
indicator.HistoricalData.AddBar(now.AddMinutes(20), 120, 130, 110, 125);
indicator.ProcessUpdate(new UpdateArgs(UpdateReason.NewBar));
Assert.Equal(2, indicator.LinesSeries[0].Count);
}
[Fact]
public void Fisher04Indicator_Parameters_CanBeChanged()
{
var indicator = new Fisher04Indicator { Period = 10 };
indicator.Period = 20;
indicator.Source = SourceType.Open;
Assert.Equal(20, indicator.Period);
Assert.Equal(SourceType.Open, indicator.Source);
Assert.Equal(0, Fisher04Indicator.MinHistoryDepths);
}
}
@@ -0,0 +1,478 @@
using Xunit;
namespace QuanTAlib.Tests;
public sealed class Fisher04Tests
{
private const double Tolerance = 1e-9;
// ───── A) Constructor validation ─────
[Fact]
public void Constructor_DefaultPeriod_IsValid()
{
var fisher = new Fisher04();
Assert.Equal(10, fisher.Period);
Assert.Equal("Fisher04(10)", fisher.Name);
}
[Fact]
public void Constructor_InvalidPeriod_Throws()
{
var ex = Assert.Throws<ArgumentException>(() => new Fisher04(period: 0));
Assert.Equal("period", ex.ParamName);
}
[Fact]
public void Constructor_NegativePeriod_Throws()
{
var ex = Assert.Throws<ArgumentException>(() => new Fisher04(period: -5));
Assert.Equal("period", ex.ParamName);
}
[Fact]
public void Constructor_CustomPeriod_SetsCorrectly()
{
var fisher = new Fisher04(period: 20);
Assert.Equal(20, fisher.Period);
Assert.Equal("Fisher04(20)", fisher.Name);
}
// ───── B) Basic calculation ─────
[Fact]
public void Update_ReturnsTValue()
{
var fisher = new Fisher04(period: 5);
var result = fisher.Update(new TValue(DateTime.UtcNow, 100.0));
Assert.IsType<TValue>(result);
}
[Fact]
public void Update_Last_IsAccessible()
{
var fisher = new Fisher04(period: 5);
fisher.Update(new TValue(DateTime.UtcNow, 100.0));
Assert.True(double.IsFinite(fisher.Last.Value));
}
[Fact]
public void Update_FisherAndSignal_Accessible()
{
var fisher = new Fisher04(period: 5);
for (int i = 0; i < 10; i++)
{
fisher.Update(new TValue(DateTime.UtcNow, 100.0 + i));
}
Assert.True(double.IsFinite(fisher.FisherValue));
Assert.True(double.IsFinite(fisher.Signal));
}
[Fact]
public void Update_RisingPrices_PositiveFisher()
{
var fisher = new Fisher04(period: 5);
for (int i = 0; i < 20; i++)
{
fisher.Update(new TValue(DateTime.UtcNow, 100.0 + i * 2));
}
Assert.True(fisher.FisherValue > 0, "Rising prices should produce positive Fisher04");
}
[Fact]
public void Update_FallingPrices_NegativeFisher()
{
var fisher = new Fisher04(period: 5);
for (int i = 0; i < 20; i++)
{
fisher.Update(new TValue(DateTime.UtcNow, 200.0 - i * 2));
}
Assert.True(fisher.FisherValue < 0, "Falling prices should produce negative Fisher04");
}
// ───── C) State + bar correction ─────
[Fact]
public void Update_IsNew_False_RollsBack()
{
var fisher = new Fisher04(period: 5);
for (int i = 0; i < 12; i++)
{
fisher.Update(new TValue(DateTime.UtcNow, 100.0 + i), isNew: true);
}
fisher.Update(new TValue(DateTime.UtcNow, 105.0), isNew: false);
var corrected = fisher.Last;
fisher.Update(new TValue(DateTime.UtcNow, 105.0), isNew: false);
var corrected2 = fisher.Last;
Assert.Equal(corrected.Value, corrected2.Value, Tolerance);
}
[Fact]
public void Update_IterativeCorrections_Restore()
{
var fisher = new Fisher04(period: 5);
double[] data = new double[15];
for (int i = 0; i < data.Length; i++)
{
data[i] = 100 + i * 2;
}
for (int i = 0; i < data.Length; i++)
{
fisher.Update(new TValue(DateTime.UtcNow, data[i]), isNew: true);
}
var baseline = fisher.Last.Value;
fisher.Update(new TValue(DateTime.UtcNow, 999.0), isNew: false);
fisher.Update(new TValue(DateTime.UtcNow, 888.0), isNew: false);
fisher.Update(new TValue(DateTime.UtcNow, data[^1]), isNew: false);
Assert.Equal(baseline, fisher.Last.Value, Tolerance);
}
[Fact]
public void Reset_ClearsState()
{
var fisher = new Fisher04(period: 5);
for (int i = 0; i < 10; i++)
{
fisher.Update(new TValue(DateTime.UtcNow, 100.0 + i));
}
fisher.Reset();
Assert.False(fisher.IsHot);
Assert.Equal(0.0, fisher.Last.Value);
}
// ───── D) Warmup/convergence ─────
[Fact]
public void IsHot_FlipsAfterPeriod()
{
int period = 10;
var fisher = new Fisher04(period);
for (int i = 0; i < period - 1; i++)
{
fisher.Update(new TValue(DateTime.UtcNow, 100.0 + i));
Assert.False(fisher.IsHot);
}
fisher.Update(new TValue(DateTime.UtcNow, 110.0));
Assert.True(fisher.IsHot);
}
[Fact]
public void WarmupPeriod_MatchesPeriod()
{
var fisher = new Fisher04(period: 14);
Assert.Equal(14, fisher.WarmupPeriod);
}
// ───── E) Robustness ─────
[Fact]
public void Update_NaN_UsesLastValid()
{
var fisher = new Fisher04(period: 5);
for (int i = 0; i < 10; i++)
{
fisher.Update(new TValue(DateTime.UtcNow, 100.0 + i));
}
_ = fisher.Last.Value;
fisher.Update(new TValue(DateTime.UtcNow, double.NaN));
Assert.True(double.IsFinite(fisher.Last.Value));
}
[Fact]
public void Update_Infinity_UsesLastValid()
{
var fisher = new Fisher04(period: 5);
for (int i = 0; i < 10; i++)
{
fisher.Update(new TValue(DateTime.UtcNow, 100.0 + i));
}
fisher.Update(new TValue(DateTime.UtcNow, double.PositiveInfinity));
Assert.True(double.IsFinite(fisher.Last.Value));
}
[Fact]
public void Update_BatchNaN_RemainsFinite()
{
var fisher = new Fisher04(period: 5);
for (int i = 0; i < 3; i++)
{
fisher.Update(new TValue(DateTime.UtcNow, double.NaN));
}
Assert.True(double.IsFinite(fisher.Last.Value));
}
// ───── F) Consistency (4 modes match) ─────
[Fact]
public void AllModes_ProduceSameResults()
{
int period = 10;
var gbm = new GBM(startPrice: 100.0, mu: 0.02, sigma: 0.1, seed: 42);
var bars = gbm.Fetch(500, DateTime.UtcNow.Ticks, TimeSpan.FromMinutes(1));
TSeries source = bars.Close;
// 1. Streaming
var streaming = new Fisher04(period);
var streamResults = new double[source.Count];
for (int i = 0; i < source.Count; i++)
{
streamResults[i] = streaming.Update(source[i]).Value;
}
// 2. Batch TSeries
TSeries batchSeries = Fisher04.Batch(source, period);
// 3. Batch Span
var spanOutput = new double[source.Count];
Fisher04.Batch(source.Values, spanOutput, period);
// 4. Event-based
var eventSource = new TSeries();
var eventIndicator = new Fisher04(eventSource, period);
var eventResults = new double[source.Count];
for (int i = 0; i < source.Count; i++)
{
eventSource.Add(source[i]);
eventResults[i] = eventIndicator.Last.Value;
}
for (int i = 0; i < source.Count; i++)
{
Assert.Equal(streamResults[i], batchSeries.Values[i], Tolerance);
Assert.Equal(streamResults[i], spanOutput[i], Tolerance);
Assert.Equal(streamResults[i], eventResults[i], Tolerance);
}
}
// ───── G) Span API tests ─────
[Fact]
public void Batch_Span_MismatchedLengths_Throws()
{
var src = new double[10];
var output = new double[5];
var ex = Assert.Throws<ArgumentException>(() => Fisher04.Batch(src, output, 5));
Assert.Equal("output", ex.ParamName);
}
[Fact]
public void Batch_Span_InvalidPeriod_Throws()
{
var src = new double[10];
var output = new double[10];
var ex = Assert.Throws<ArgumentException>(() => Fisher04.Batch(src, output, 0));
Assert.Equal("period", ex.ParamName);
}
[Fact]
public void Batch_Span_Empty_NoException()
{
var src = ReadOnlySpan<double>.Empty;
var output = Span<double>.Empty;
Fisher04.Batch(src, output, 5);
Assert.True(true);
}
[Fact]
public void Batch_Span_MatchesTSeries()
{
var gbm = new GBM(startPrice: 100.0, mu: 0.02, sigma: 0.1, seed: 42);
var bars = gbm.Fetch(200, DateTime.UtcNow.Ticks, TimeSpan.FromMinutes(1));
TSeries source = bars.Close;
TSeries batchSeries = Fisher04.Batch(source, 10);
var spanOutput = new double[source.Count];
Fisher04.Batch(source.Values, spanOutput, 10);
for (int i = 0; i < source.Count; i++)
{
Assert.Equal(batchSeries.Values[i], spanOutput[i], 12);
}
}
[Fact]
public void Batch_Span_NaN_Handled()
{
double[] src = [100, 101, double.NaN, 103, 104, 105, 106, 107, 108, 109];
var output = new double[src.Length];
Fisher04.Batch(src, output, 5);
for (int i = 0; i < output.Length; i++)
{
Assert.True(double.IsFinite(output[i]));
}
}
// ───── H) Chainability ─────
[Fact]
public void Event_PubFires()
{
var source = new TSeries();
var fisher = new Fisher04(source, period: 5);
int count = 0;
fisher.Pub += (object? _, in TValueEventArgs _) => count++;
source.Add(new TValue(DateTime.UtcNow, 100.0));
Assert.Equal(1, count);
}
[Fact]
public void Event_ChainingWorks()
{
var source = new TSeries();
var fisher = new Fisher04(source, period: 5);
for (int i = 0; i < 20; i++)
{
source.Add(new TValue(DateTime.UtcNow, 100.0 + i));
}
Assert.True(fisher.IsHot);
Assert.True(double.IsFinite(fisher.Last.Value));
}
// ───── Domain-specific tests ─────
[Fact]
public void Fisher04_DifferentFromFisher2002()
{
// Fisher04 uses different coefficients (0.25 arctanh mult vs 0.5)
// so results MUST differ from Fisher (2002)
int period = 10;
var gbm = new GBM(startPrice: 100.0, mu: 0.02, sigma: 0.1, seed: 42);
var bars = gbm.Fetch(100, DateTime.UtcNow.Ticks, TimeSpan.FromMinutes(1));
TSeries source = bars.Close;
var fisher02 = new Fisher(period);
var fisher04 = new Fisher04(period);
double last02 = 0, last04 = 0;
for (int i = 0; i < source.Count; i++)
{
last02 = fisher02.Update(source[i]).Value;
last04 = fisher04.Update(source[i]).Value;
}
Assert.NotEqual(last02, last04, 1e-3);
}
[Fact]
public void Fisher04_SmallerAmplitudeThanFisher2002()
{
// The 0.25 multiplier (vs 0.5) means Fisher04 should generally
// produce smaller absolute values than Fisher 2002
int period = 10;
var gbm = new GBM(startPrice: 100.0, mu: 0.05, sigma: 0.15, seed: 42);
var bars = gbm.Fetch(200, DateTime.UtcNow.Ticks, TimeSpan.FromMinutes(1));
TSeries source = bars.Close;
var fisher02 = new Fisher(period);
var fisher04 = new Fisher04(period);
double sum02 = 0, sum04 = 0;
for (int i = 0; i < source.Count; i++)
{
sum02 += Math.Abs(fisher02.Update(source[i]).Value);
sum04 += Math.Abs(fisher04.Update(source[i]).Value);
}
Assert.True(sum04 < sum02,
$"Fisher04 avg abs ({sum04 / source.Count:F4}) should be smaller than Fisher ({sum02 / source.Count:F4})");
}
[Fact]
public void FisherTransform_MathematicalProperties()
{
// Fisher Transform is arctanh: should be odd function
// For normalized input 0, Fisher should be 0
var fisher = new Fisher04(period: 5);
// Feed constant price → normalized = 0 → Fisher ≈ 0
for (int i = 0; i < 20; i++)
{
fisher.Update(new TValue(DateTime.UtcNow, 100.0));
}
Assert.True(Math.Abs(fisher.FisherValue) < 0.1,
$"Constant price should produce Fisher near 0, got {fisher.FisherValue}");
}
[Fact]
public void FisherTransform_OutputIsUnbounded()
{
// Fisher can exceed ±2 with strong trends (though Fisher04 is gentler)
var fisher = new Fisher04(period: 5);
// Create a very strong uptrend
for (int i = 0; i < 30; i++)
{
fisher.Update(new TValue(DateTime.UtcNow, 100.0 + i * 10));
}
// Fisher04 should be positive for uptrend
Assert.True(fisher.FisherValue > 0.5,
$"Strong uptrend should produce Fisher04 > 0.5, got {fisher.FisherValue}");
}
[Fact]
public void Signal_LagsFisher()
{
// Signal is Fish[1], so under strong trend it should lag
var fisher = new Fisher04(period: 5);
for (int i = 0; i < 30; i++)
{
fisher.Update(new TValue(DateTime.UtcNow, 100.0 + i * 5));
}
// Both should be positive in uptrend
Assert.True(fisher.FisherValue > 0);
Assert.True(fisher.Signal > 0);
}
[Fact]
public void ManualCalculation_MatchesExpected()
{
// Verify the 2004 algorithm coefficients against manual computation
var fisher = new Fisher04(period: 3);
// Feed 3 values to fill the buffer
fisher.Update(new TValue(DateTime.UtcNow, 10.0), isNew: true);
fisher.Update(new TValue(DateTime.UtcNow, 12.0), isNew: true);
fisher.Update(new TValue(DateTime.UtcNow, 11.0), isNew: true);
// Manual: buffer = [10, 12, 11], min=10, max=12, range=2
// norm = (11-10)/2 - 0.5 = 0.5 - 0.5 = 0.0
// But we have IIR from previous bars...
// Bar 0: val=10, min=max=10, range=0 → Value1=0, Fish=0
// Bar 1: val=12, min=10,max=12,range=2, norm=(12-10)/2-0.5=0.5
// Value1 = 0.5 + 0.5*0 = 0.5
// Fish = 0.25*ln((1.5)/(0.5)) + 0.5*0 = 0.25*ln(3) = 0.25*1.0986... = 0.27465...
// Bar 2: val=11, min=10,max=12,range=2, norm=(11-10)/2-0.5=0.0
// Value1 = 0.0 + 0.5*0.5 = 0.25
// Fish = 0.25*ln(1.25/0.75) + 0.5*0.27465... = 0.25*ln(1.6667) + 0.13733...
// = 0.25*0.51083... + 0.13733... = 0.12771... + 0.13733... = 0.26504...
double expectedBar1Fish = 0.25 * Math.Log(1.5 / 0.5);
double expectedBar2Value1 = 0.25;
double expectedBar2Fish = (0.25 * Math.Log((1.0 + expectedBar2Value1) / (1.0 - expectedBar2Value1)))
+ (0.5 * expectedBar1Fish);
Assert.Equal(expectedBar2Fish, fisher.FisherValue, 1e-10);
}
}
@@ -0,0 +1,303 @@
using Xunit;
using Xunit.Abstractions;
namespace QuanTAlib.Tests;
/// <summary>
/// Validation tests for Fisher04 (Ehlers 2004 Cybernetic Analysis).
/// No external library implements this specific variant, so we validate:
/// 1. Manual step-by-step computation against the algorithm
/// 2. Batch vs streaming consistency
/// 3. Span vs streaming consistency
/// 4. Coefficient differences from Fisher (2002)
/// </summary>
public sealed class Fisher04ValidationTests(ITestOutputHelper output) : IDisposable
{
private const double Tolerance = 1e-12;
private const int Seed = 12345;
private const int DataPoints = 500;
public void Dispose()
{
Dispose(true);
GC.SuppressFinalize(this);
}
private void Dispose(bool disposing)
{
// No unmanaged resources
}
/// <summary>
/// Validates the exact Ehlers 2004 algorithm step-by-step for 5 bars.
/// </summary>
[Fact]
public void ManualComputation_5Bars_MatchesAlgorithm()
{
double[] prices = [10.0, 12.0, 11.0, 13.0, 9.0];
int period = 3;
var fisher = new Fisher04(period);
// Track expected values manually
double value1 = 0.0;
double fishPrev = 0.0;
var buffer = new List<double>();
for (int i = 0; i < prices.Length; i++)
{
double price = prices[i];
buffer.Add(price);
if (buffer.Count > period)
{
buffer.RemoveAt(0);
}
double high = double.MinValue;
double low = double.MaxValue;
for (int j = 0; j < buffer.Count; j++)
{
if (buffer[j] > high)
{
high = buffer[j];
}
if (buffer[j] < low)
{
low = buffer[j];
}
}
double range = high - low;
if (range != 0.0)
{
value1 = (((price - low) / range) - 0.5) + (0.5 * value1);
}
else
{
value1 = 0.0;
}
if (value1 > 0.9999)
{
value1 = 0.9999;
}
else if (value1 < -0.9999)
{
value1 = -0.9999;
}
double fish = (0.25 * Math.Log((1.0 + value1) / (1.0 - value1)))
+ (0.5 * fishPrev);
var result = fisher.Update(new TValue(DateTime.UtcNow, price));
output.WriteLine($"Bar {i}: price={price:F1} range={range:F1} value1={value1:F10} fish={fish:F10} actual={result.Value:F10}");
Assert.Equal(fish, result.Value, Tolerance);
fishPrev = fish;
}
}
/// <summary>
/// Streaming matches batch TSeries output.
/// </summary>
[Fact]
public void Streaming_MatchesBatch_TSeries()
{
int period = 10;
var gbm = new GBM(startPrice: 100.0, mu: 0.02, sigma: 0.1, seed: Seed);
var bars = gbm.Fetch(DataPoints, DateTime.UtcNow.Ticks, TimeSpan.FromMinutes(1));
TSeries source = bars.Close;
// Streaming
var streaming = new Fisher04(period);
var streamResults = new double[source.Count];
for (int i = 0; i < source.Count; i++)
{
streamResults[i] = streaming.Update(source[i]).Value;
}
// Batch
TSeries batchResults = Fisher04.Batch(source, period);
int mismatches = 0;
for (int i = 0; i < source.Count; i++)
{
if (Math.Abs(streamResults[i] - batchResults.Values[i]) > Tolerance)
{
mismatches++;
if (mismatches <= 5)
{
output.WriteLine($"Mismatch at {i}: stream={streamResults[i]:F12} batch={batchResults.Values[i]:F12}");
}
}
}
output.WriteLine($"Total mismatches: {mismatches}/{source.Count}");
Assert.Equal(0, mismatches);
}
/// <summary>
/// Streaming matches span batch output.
/// </summary>
[Fact]
public void Streaming_MatchesBatch_Span()
{
int period = 10;
var gbm = new GBM(startPrice: 100.0, mu: 0.02, sigma: 0.1, seed: Seed);
var bars = gbm.Fetch(DataPoints, DateTime.UtcNow.Ticks, TimeSpan.FromMinutes(1));
TSeries source = bars.Close;
// Streaming
var streaming = new Fisher04(period);
var streamResults = new double[source.Count];
for (int i = 0; i < source.Count; i++)
{
streamResults[i] = streaming.Update(source[i]).Value;
}
// Span batch
var spanOutput = new double[source.Count];
Fisher04.Batch(source.Values, spanOutput, period);
int mismatches = 0;
for (int i = 0; i < source.Count; i++)
{
if (Math.Abs(streamResults[i] - spanOutput[i]) > Tolerance)
{
mismatches++;
if (mismatches <= 5)
{
output.WriteLine($"Mismatch at {i}: stream={streamResults[i]:F12} span={spanOutput[i]:F12}");
}
}
}
output.WriteLine($"Total mismatches: {mismatches}/{source.Count}");
Assert.Equal(0, mismatches);
}
/// <summary>
/// Verifies that Fisher04 (2004) produces different results from Fisher (2002)
/// due to different coefficients, and that the amplitude is reduced.
/// </summary>
[Fact]
public void Fisher04_DiffersFromFisher2002_WithSmallerAmplitude()
{
int period = 10;
var gbm = new GBM(startPrice: 100.0, mu: 0.03, sigma: 0.12, seed: Seed);
var bars = gbm.Fetch(DataPoints, DateTime.UtcNow.Ticks, TimeSpan.FromMinutes(1));
TSeries source = bars.Close;
var fisher02 = new Fisher(period);
var fisher04 = new Fisher04(period);
double sumAbs02 = 0, sumAbs04 = 0;
int diffCount = 0;
for (int i = 0; i < source.Count; i++)
{
double v02 = fisher02.Update(source[i]).Value;
double v04 = fisher04.Update(source[i]).Value;
sumAbs02 += Math.Abs(v02);
sumAbs04 += Math.Abs(v04);
if (Math.Abs(v02 - v04) > 1e-6)
{
diffCount++;
}
}
double avgAbs02 = sumAbs02 / source.Count;
double avgAbs04 = sumAbs04 / source.Count;
output.WriteLine($"Fisher 2002 avg |value|: {avgAbs02:F6}");
output.WriteLine($"Fisher04 2004 avg |value|: {avgAbs04:F6}");
output.WriteLine($"Different values: {diffCount}/{source.Count}");
// They should differ on most bars
Assert.True(diffCount > source.Count * 0.9,
$"Expected >90% different values, got {diffCount}/{source.Count}");
// Fisher04 should have smaller amplitude (0.25 mult vs 0.5)
Assert.True(avgAbs04 < avgAbs02,
$"Fisher04 avg abs ({avgAbs04:F6}) should be < Fisher ({avgAbs02:F6})");
}
/// <summary>
/// Validates coefficient correctness: the normalization coefficient is 1.0 (not 0.66).
/// </summary>
[Fact]
public void NormalizationCoefficient_IsOne()
{
// With period=2 and prices [100, 110]:
// range = 10, norm = (110-100)/10 - 0.5 = 0.5
// Value1 = 1.0 * 0.5 + 0.5 * prev
// For Fisher (2002): Value1 = 0.66 * 0.5 + 0.67 * prev = 0.33 + 0.67*prev
// For Fisher04 (2004): Value1 = 1.0 * 0.5 + 0.5 * prev = 0.5 + 0.5*prev
var fisher04 = new Fisher04(period: 2);
fisher04.Update(new TValue(DateTime.UtcNow, 100.0), isNew: true); // range=0 → value1=0
fisher04.Update(new TValue(DateTime.UtcNow, 110.0), isNew: true); // value1 = 0.5 + 0 = 0.5
// fish = 0.25 * ln(1.5/0.5) + 0 = 0.25 * ln(3)
double expectedFish = 0.25 * Math.Log(3.0);
Assert.Equal(expectedFish, fisher04.FisherValue, 1e-10);
}
/// <summary>
/// Multiple periods produce correct results.
/// </summary>
[Theory]
[InlineData(5)]
[InlineData(10)]
[InlineData(20)]
[InlineData(50)]
public void DifferentPeriods_ProduceFiniteResults(int period)
{
var gbm = new GBM(startPrice: 100.0, mu: 0.02, sigma: 0.1, seed: Seed);
var bars = gbm.Fetch(200, DateTime.UtcNow.Ticks, TimeSpan.FromMinutes(1));
TSeries source = bars.Close;
var fisher = new Fisher04(period);
for (int i = 0; i < source.Count; i++)
{
var result = fisher.Update(source[i]);
Assert.True(double.IsFinite(result.Value), $"Non-finite at bar {i} with period {period}");
}
Assert.True(fisher.IsHot);
}
/// <summary>
/// Validates the clamp threshold is 0.9999 (not 0.99/0.999).
/// </summary>
[Fact]
public void ClampThreshold_Is09999()
{
// Create a scenario where Value1 would exceed 0.9999
// With period=2 and extreme price movement
var fisher = new Fisher04(period: 2);
// First bar: range=0 → value1=0
fisher.Update(new TValue(DateTime.UtcNow, 100.0), isNew: true);
// Second bar: range=100, norm=(200-100)/100 - 0.5 = 0.5
// value1 = 0.5 + 0 = 0.5 (not clamped)
fisher.Update(new TValue(DateTime.UtcNow, 200.0), isNew: true);
// Third bar: range=200-100=100, norm=(300-100)/200 - 0.5 = 0.5
// value1 = 0.5 + 0.5*0.5 = 0.75 (not clamped yet)
fisher.Update(new TValue(DateTime.UtcNow, 300.0), isNew: true);
// Keep feeding extreme values to push value1 toward clamp
for (int i = 0; i < 50; i++)
{
fisher.Update(new TValue(DateTime.UtcNow, 100.0 + (i + 4) * 100.0), isNew: true);
}
// Fisher should remain finite (clamping prevents log(∞))
Assert.True(double.IsFinite(fisher.FisherValue),
$"Fisher should be finite after extreme values, got {fisher.FisherValue}");
}
}