Files
Miha Kralj 67ad6f0cba v0.8.7: Replace periodic ResyncInterval with Kahan compensated summation
Comprehensive refactor across all indicators replacing the periodic
ResyncInterval-based drift correction (every 1000 ticks recalculate
from scratch) with Kahan compensated summation for running sums.

Key changes:
- Remove ResyncInterval constants and TickCount fields from all State records
- Add Kahan compensation fields (SumComp, SumSqComp, etc.) to State records
- Replace naive sum += val - removed with Kahan delta pattern
- Remove Resync()/RecalculateSum() methods that did O(N) recalculation
- Update batch/SIMD paths to use Kahan compensation instead of resync loops
- IIR filters (EMA, REMA, RGMA) simplified: inherently self-correcting
- Version bump to 0.8.7
- Build system: README version stamping via Directory.Build.props
- Minor doc/test tolerance adjustments for new numerical characteristics

Affected modules: channels, core, cycles, dynamics, errors, momentum,
oscillators, statistics, trends_FIR, trends_IIR, volatility, volume
2026-03-13 22:01:31 -07:00

703 lines
22 KiB
C#

namespace QuanTAlib.Tests;
public class RemaTests
{
[Fact]
public void Rema_Constructor_Period_ValidatesInput()
{
Assert.Throws<ArgumentOutOfRangeException>(() => new Rema(0));
Assert.Throws<ArgumentOutOfRangeException>(() => new Rema(-1));
var rema = new Rema(10);
Assert.NotNull(rema);
}
[Fact]
public void Rema_Constructor_Lambda_ValidatesInput()
{
Assert.Throws<ArgumentOutOfRangeException>(() => new Rema(10, -0.1));
Assert.Throws<ArgumentOutOfRangeException>(() => new Rema(10, 1.1));
var rema1 = new Rema(10, 0.0);
var rema2 = new Rema(10, 1.0);
var rema3 = new Rema(10, 0.5);
Assert.NotNull(rema1);
Assert.NotNull(rema2);
Assert.NotNull(rema3);
}
[Fact]
public void Rema_Calc_ReturnsValue()
{
var rema = new Rema(10);
Assert.Equal(0, rema.Last.Value);
TValue result = rema.Update(new TValue(DateTime.UtcNow, 100));
Assert.True(result.Value > 0);
Assert.Equal(result.Value, rema.Last.Value);
}
[Fact]
public void Rema_Calc_IsNew_AcceptsParameter()
{
var rema = new Rema(10);
rema.Update(new TValue(DateTime.UtcNow, 100), isNew: true);
double value1 = rema.Last.Value;
rema.Update(new TValue(DateTime.UtcNow, 105), isNew: true);
double value2 = rema.Last.Value;
// Values should change with new bars
Assert.NotEqual(value1, value2);
}
[Fact]
public void Rema_Calc_IsNew_False_UpdatesValue()
{
var rema = new Rema(10);
rema.Update(new TValue(DateTime.UtcNow, 100));
rema.Update(new TValue(DateTime.UtcNow, 110), isNew: true);
double beforeUpdate = rema.Last.Value;
rema.Update(new TValue(DateTime.UtcNow, 120), isNew: false);
double afterUpdate = rema.Last.Value;
// Update should change the value
Assert.NotEqual(beforeUpdate, afterUpdate);
}
[Fact]
public void Rema_Reset_ClearsState()
{
var rema = new Rema(10);
rema.Update(new TValue(DateTime.UtcNow, 100));
rema.Update(new TValue(DateTime.UtcNow, 105));
double valueBefore = rema.Last.Value;
rema.Reset();
Assert.Equal(0, rema.Last.Value);
// After reset, should accept new values
rema.Update(new TValue(DateTime.UtcNow, 50));
Assert.NotEqual(0, rema.Last.Value);
Assert.NotEqual(valueBefore, rema.Last.Value);
}
[Fact]
public void Rema_Properties_Accessible()
{
var rema = new Rema(10);
Assert.Equal(0, rema.Last.Value);
Assert.False(rema.IsHot);
rema.Update(new TValue(DateTime.UtcNow, 100));
Assert.NotEqual(0, rema.Last.Value);
}
[Fact]
public void Rema_IsHot_BecomesTrueAfterWarmup()
{
var rema = new Rema(10);
// Initially IsHot should be false
Assert.False(rema.IsHot);
int steps = 0;
while (!rema.IsHot && steps < 1000)
{
rema.Update(new TValue(DateTime.UtcNow, 100));
steps++;
}
Assert.True(rema.IsHot);
Assert.True(steps > 0);
// Similar to EMA, should become hot around 15 bars for period 10
Assert.InRange(steps, 14, 17);
}
[Fact]
public void Rema_IsHot_IsPeriodDependent()
{
int[] periods = [10, 20, 50];
int[] expectedSteps = new int[periods.Length];
for (int i = 0; i < periods.Length; i++)
{
int period = periods[i];
var rema = new Rema(period);
int steps = 0;
while (!rema.IsHot && steps < 500)
{
rema.Update(new TValue(DateTime.UtcNow, 100));
steps++;
}
expectedSteps[i] = steps;
}
// Verify warmup times increase with period
Assert.True(expectedSteps[0] < expectedSteps[1], $"Period 10 ({expectedSteps[0]}) should be less than Period 20 ({expectedSteps[1]})");
Assert.True(expectedSteps[1] < expectedSteps[2], $"Period 20 ({expectedSteps[1]}) should be less than Period 50 ({expectedSteps[2]})");
}
[Fact]
public void Rema_Lambda1_ApproachesEma()
{
// With lambda=1, REMA should behave similarly to EMA
var rema = new Rema(10, lambda: 1.0);
var ema = new Ema(10);
var gbm = new GBM(startPrice: 100.0, mu: 0.02, sigma: 0.1, seed: 42);
for (int i = 0; i < 100; i++)
{
var bar = gbm.Next(isNew: true);
var input = new TValue(bar.Time, bar.Close);
rema.Update(input);
ema.Update(input);
}
// With lambda=1, REMA should be very close to EMA
Assert.Equal(ema.Last.Value, rema.Last.Value, 1e-6);
}
[Fact]
public void Rema_Lambda0_MaxRegularization()
{
// With lambda=0, REMA uses pure momentum continuation
var rema0 = new Rema(10, lambda: 0.0);
var rema05 = new Rema(10, lambda: 0.5);
var rema1 = new Rema(10, lambda: 1.0);
var gbm = new GBM(startPrice: 100.0, mu: 0.02, sigma: 0.1, seed: 42);
for (int i = 0; i < 50; i++)
{
var bar = gbm.Next(isNew: true);
var input = new TValue(bar.Time, bar.Close);
rema0.Update(input);
rema05.Update(input);
rema1.Update(input);
}
// All should produce finite values
Assert.True(double.IsFinite(rema0.Last.Value));
Assert.True(double.IsFinite(rema05.Last.Value));
Assert.True(double.IsFinite(rema1.Last.Value));
// They should generally differ (lambda affects behavior)
// Note: exact equality is unlikely with different lambdas
}
[Fact]
public void Rema_IterativeCorrections_RestoreToOriginalState()
{
var rema = new Rema(10);
var gbm = new GBM(startPrice: 100.0, mu: 0.02, sigma: 0.1);
// Feed 10 new values
TValue tenthInput = default;
for (int i = 0; i < 10; i++)
{
var bar = gbm.Next(isNew: true);
tenthInput = new TValue(bar.Time, bar.Close);
rema.Update(tenthInput, isNew: true);
}
// Remember state after 10 values
double remaAfterTen = rema.Last.Value;
// Generate 9 corrections with isNew=false (different values)
for (int i = 0; i < 9; i++)
{
var bar = gbm.Next(isNew: false);
rema.Update(new TValue(bar.Time, bar.Close), isNew: false);
}
// Feed the remembered 10th input again with isNew=false
TValue finalRema = rema.Update(tenthInput, isNew: false);
// Should match the original state after 10 values
Assert.Equal(remaAfterTen, finalRema.Value, 1e-10);
}
[Fact]
public void Rema_BatchCalc_MatchesIterativeCalc()
{
var remaIterative = new Rema(10);
var remaBatch = new Rema(10);
var gbm = new GBM(startPrice: 100.0, mu: 0.02, sigma: 0.1);
// Generate data
var series = new TSeries();
for (int i = 0; i < 100; i++)
{
var bar = gbm.Next(isNew: true);
series.Add(bar.Time, bar.Close);
}
Assert.True(series.Count > 0);
// Calculate iteratively
var iterativeResults = new TSeries();
foreach (var item in series)
{
iterativeResults.Add(remaIterative.Update(item));
}
// Calculate batch
var batchResults = remaBatch.Update(series);
// Compare
Assert.Equal(iterativeResults.Count, batchResults.Count);
for (int i = 0; i < iterativeResults.Count; i++)
{
Assert.Equal(iterativeResults[i].Value, batchResults[i].Value, 1e-10);
Assert.Equal(iterativeResults[i].Time, batchResults[i].Time);
}
}
[Fact]
public void Rema_NaN_Input_UsesLastValidValue()
{
var rema = new Rema(10);
// Feed some valid values
rema.Update(new TValue(DateTime.UtcNow, 100));
rema.Update(new TValue(DateTime.UtcNow, 110));
// Feed NaN - should use last valid value (110)
var resultAfterNaN = rema.Update(new TValue(DateTime.UtcNow, double.NaN));
// Result should be finite (not NaN)
Assert.True(double.IsFinite(resultAfterNaN.Value));
Assert.NotEqual(0, resultAfterNaN.Value);
}
[Fact]
public void Rema_Infinity_Input_UsesLastValidValue()
{
var rema = new Rema(10);
// Feed some valid values
rema.Update(new TValue(DateTime.UtcNow, 100));
rema.Update(new TValue(DateTime.UtcNow, 110));
// Feed positive infinity - should use last valid value
var resultAfterPosInf = rema.Update(new TValue(DateTime.UtcNow, double.PositiveInfinity));
Assert.True(double.IsFinite(resultAfterPosInf.Value));
// Feed negative infinity - should use last valid value
var resultAfterNegInf = rema.Update(new TValue(DateTime.UtcNow, double.NegativeInfinity));
Assert.True(double.IsFinite(resultAfterNegInf.Value));
}
[Fact]
public void Rema_MultipleNaN_ContinuesWithLastValid()
{
var rema = new Rema(10);
// Feed valid values
rema.Update(new TValue(DateTime.UtcNow, 100));
rema.Update(new TValue(DateTime.UtcNow, 110));
rema.Update(new TValue(DateTime.UtcNow, 120));
// Feed multiple NaN values
var r1 = rema.Update(new TValue(DateTime.UtcNow, double.NaN));
var r2 = rema.Update(new TValue(DateTime.UtcNow, double.NaN));
var r3 = rema.Update(new TValue(DateTime.UtcNow, double.NaN));
// All results should be finite
Assert.True(double.IsFinite(r1.Value));
Assert.True(double.IsFinite(r2.Value));
Assert.True(double.IsFinite(r3.Value));
}
[Fact]
public void Rema_BatchCalc_HandlesNaN()
{
var rema = new Rema(10);
// Create series with NaN values interspersed
var series = new TSeries();
series.Add(DateTime.UtcNow.Ticks, 100);
series.Add(DateTime.UtcNow.Ticks + 1, 110);
series.Add(DateTime.UtcNow.Ticks + 2, double.NaN);
series.Add(DateTime.UtcNow.Ticks + 3, 120);
series.Add(DateTime.UtcNow.Ticks + 4, double.PositiveInfinity);
series.Add(DateTime.UtcNow.Ticks + 5, 130);
var results = rema.Update(series);
// All results should be finite
foreach (var result in results)
{
Assert.True(double.IsFinite(result.Value), $"Expected finite value but got {result.Value}");
}
}
[Fact]
public void Rema_Reset_ClearsLastValidValue()
{
var rema = new Rema(10);
// Feed values including NaN
rema.Update(new TValue(DateTime.UtcNow, 100));
rema.Update(new TValue(DateTime.UtcNow, double.NaN));
// Reset
rema.Reset();
// After reset, first valid value should establish new baseline
var result = rema.Update(new TValue(DateTime.UtcNow, 50));
Assert.Equal(50.0, result.Value, 1e-10);
}
// ============== Span API Tests ==============
[Fact]
public void Rema_SpanBatch_Period_ValidatesInput()
{
double[] source = [1, 2, 3, 4, 5];
double[] output = new double[5];
double[] wrongSizeOutput = new double[3];
// Period must be > 0
Assert.Throws<ArgumentException>(() => Rema.Batch(source.AsSpan(), output.AsSpan(), 0));
Assert.Throws<ArgumentException>(() => Rema.Batch(source.AsSpan(), output.AsSpan(), -1));
// Output must be same length as source
Assert.Throws<ArgumentException>(() => Rema.Batch(source.AsSpan(), wrongSizeOutput.AsSpan(), 3));
}
[Fact]
public void Rema_SpanBatch_Lambda_ValidatesInput()
{
double[] source = [1, 2, 3, 4, 5];
double[] output = new double[5];
// Lambda must be >= 0 and <= 1
Assert.Throws<ArgumentOutOfRangeException>(() => Rema.Batch(source.AsSpan(), output.AsSpan(), 3, -0.1));
Assert.Throws<ArgumentOutOfRangeException>(() => Rema.Batch(source.AsSpan(), output.AsSpan(), 3, 1.1));
}
[Fact]
public void Rema_SpanBatch_MatchesTSeriesBatch()
{
var series = new TSeries();
double[] source = new double[100];
double[] output = new double[100];
var gbm = new GBM(startPrice: 100.0, mu: 0.02, sigma: 0.1, seed: 42);
for (int i = 0; i < 100; i++)
{
var bar = gbm.Next(isNew: true);
source[i] = bar.Close;
series.Add(bar.Time, bar.Close);
}
// Calculate with TSeries API
var tseriesResult = Rema.Batch(series, 10);
// Calculate with Span API
Rema.Batch(source.AsSpan(), output.AsSpan(), 10);
// Compare results
for (int i = 0; i < 100; i++)
{
Assert.Equal(tseriesResult[i].Value, output[i], 1e-9);
}
}
[Fact]
public void Rema_SpanBatch_DifferentLambdas()
{
double[] source = [10, 20, 30, 40, 50, 60, 70, 80, 90, 100];
double[] output0 = new double[10];
double[] output05 = new double[10];
double[] output1 = new double[10];
Rema.Batch(source.AsSpan(), output0.AsSpan(), 5, 0.0);
Rema.Batch(source.AsSpan(), output05.AsSpan(), 5, 0.5);
Rema.Batch(source.AsSpan(), output1.AsSpan(), 5, 1.0);
// All should produce finite results
for (int i = 0; i < 10; i++)
{
Assert.True(double.IsFinite(output0[i]));
Assert.True(double.IsFinite(output05[i]));
Assert.True(double.IsFinite(output1[i]));
}
}
[Fact]
public void Rema_SpanBatch_ZeroAllocation()
{
double[] source = new double[10000];
double[] output = new double[10000];
var gbm = new GBM(startPrice: 100, mu: 0.05, sigma: 0.2, seed: 42);
for (int i = 0; i < source.Length; i++)
{
source[i] = gbm.Next().Close;
}
// Warm up
Rema.Batch(source.AsSpan(), output.AsSpan(), 100);
// This test verifies the method runs without throwing
Assert.True(double.IsFinite(output[^1]));
}
[Fact]
public void Rema_SpanBatch_HandlesNaN()
{
double[] source = [100, 110, double.NaN, 120, 130];
double[] output = new double[5];
Rema.Batch(source.AsSpan(), output.AsSpan(), 3);
// All outputs should be finite
foreach (var val in output)
{
Assert.True(double.IsFinite(val), $"Expected finite value but got {val}");
}
}
[Fact]
public void Chainability_Works()
{
var source = new TSeries();
var rema = new Rema(source, 10);
source.Add(new TValue(DateTime.UtcNow, 100));
Assert.Equal(100, rema.Last.Value, 1e-10);
}
[Fact]
public void Prime_SetsStateCorrectly()
{
var rema = new Rema(5);
double[] history = [10, 20, 30, 40, 50];
rema.Prime(history);
// Verify against a fresh REMA fed with same data
var verifyRema = new Rema(5);
foreach (var val in history)
{
verifyRema.Update(new TValue(DateTime.UtcNow, val));
}
Assert.Equal(verifyRema.Last.Value, rema.Last.Value, 1e-10);
Assert.Equal(verifyRema.IsHot, rema.IsHot);
// Verify it continues correctly
rema.Update(new TValue(DateTime.UtcNow, 60));
verifyRema.Update(new TValue(DateTime.UtcNow, 60));
Assert.Equal(verifyRema.Last.Value, rema.Last.Value, 1e-10);
}
[Fact]
public void Prime_HandlesNaN_InHistory()
{
var rema = new Rema(5);
double[] history = [10, 20, double.NaN, 40, 50];
rema.Prime(history);
var verifyRema = new Rema(5);
foreach (var val in history)
{
verifyRema.Update(new TValue(DateTime.UtcNow, val));
}
Assert.Equal(verifyRema.Last.Value, rema.Last.Value, 1e-10);
}
[Fact]
public void Prime_AllNaNs_ReturnsNaN()
{
var rema = new Rema(5);
double[] history = [double.NaN, double.NaN, double.NaN];
rema.Prime(history);
Assert.True(double.IsNaN(rema.Last.Value));
}
[Fact]
public void Calculate_ReturnsCorrectResultsAndHotIndicator()
{
var series = new TSeries();
for (int i = 1; i <= 20; i++)
{
series.Add(DateTime.UtcNow, i * 10);
}
var (results, indicator) = Rema.Calculate(series, 5);
// Check results
Assert.Equal(20, results.Count);
// Verify against standard calculation
var verifyRema = new Rema(5);
var verifyResults = verifyRema.Update(series);
Assert.Equal(verifyResults.Last.Value, results.Last.Value, 1e-10);
Assert.Equal(verifyRema.Last.Value, indicator.Last.Value, 1e-10);
// Check indicator state
Assert.True(indicator.IsHot);
// Verify indicator continues correctly
indicator.Update(new TValue(DateTime.UtcNow, 210));
verifyRema.Update(new TValue(DateTime.UtcNow, 210));
Assert.Equal(verifyRema.Last.Value, indicator.Last.Value, 1e-10);
}
[Fact]
public void Rema_Batch_AllNaNs_ReturnsNaN()
{
double[] source = [double.NaN, double.NaN, double.NaN];
double[] output = new double[3];
Rema.Batch(source.AsSpan(), output.AsSpan(), 5);
// Should be all NaNs, not 0s
foreach (var val in output)
{
Assert.True(double.IsNaN(val), $"Expected NaN but got {val}");
}
}
[Fact]
public void Rema_AllModes_ProduceSameResult()
{
// Arrange
int period = 10;
double lambda = 0.5;
var gbm = new GBM(startPrice: 100, mu: 0.05, sigma: 0.2, seed: 123);
var bars = gbm.Fetch(1000, DateTime.UtcNow.Ticks, TimeSpan.FromMinutes(1));
var series = bars.Close;
// 1. Batch Mode
var batchSeries = Rema.Batch(series, period, lambda);
double expected = batchSeries.Last.Value;
// 2. Span Mode
var tValues = series.Values.ToArray();
var spanInput = new ReadOnlySpan<double>(tValues);
var spanOutput = new double[tValues.Length];
Rema.Batch(spanInput, spanOutput, period, lambda);
double spanResult = spanOutput[^1];
// 3. Streaming Mode
var streamingInd = new Rema(period, lambda);
for (int i = 0; i < series.Count; i++)
{
streamingInd.Update(series[i]);
}
double streamingResult = streamingInd.Last.Value;
// 4. Eventing Mode
var pubSource = new TSeries();
var eventingInd = new Rema(pubSource, period, lambda);
for (int i = 0; i < series.Count; i++)
{
pubSource.Add(series[i]);
}
double eventingResult = eventingInd.Last.Value;
// Assert
Assert.Equal(expected, spanResult, precision: 9);
Assert.Equal(expected, streamingResult, precision: 9);
Assert.Equal(expected, eventingResult, precision: 9);
}
[Fact]
public void Rema_AllModes_ProduceSameResult_AfterResyncInterval()
{
// Guards against implementation drift between CalculateCore (batch/span)
// and Update(TValue) (streaming/eventing) over long runs.
int period = 10;
double lambda = 0.5;
int count = 12050; // Long-running consistency check
var gbm = new GBM(startPrice: 100, mu: 0.05, sigma: 0.2, seed: 321);
var bars = gbm.Fetch(count, DateTime.UtcNow.Ticks, TimeSpan.FromMinutes(1));
var series = bars.Close;
// 1. Batch Mode
var batchSeries = Rema.Batch(series, period, lambda);
double expected = batchSeries.Last.Value;
// 2. Span Mode
var tValues = series.Values.ToArray();
var spanInput = new ReadOnlySpan<double>(tValues);
var spanOutput = new double[tValues.Length];
Rema.Batch(spanInput, spanOutput, period, lambda);
double spanResult = spanOutput[^1];
// 3. Streaming Mode
var streamingInd = new Rema(period, lambda);
for (int i = 0; i < series.Count; i++)
{
streamingInd.Update(series[i]);
}
double streamingResult = streamingInd.Last.Value;
// 4. Eventing Mode
var pubSource = new TSeries();
var eventingInd = new Rema(pubSource, period, lambda);
for (int i = 0; i < series.Count; i++)
{
pubSource.Add(series[i]);
}
double eventingResult = eventingInd.Last.Value;
Assert.Equal(expected, spanResult, precision: 9);
Assert.Equal(expected, streamingResult, precision: 9);
Assert.Equal(expected, eventingResult, precision: 9);
}
[Fact]
public void Prime_ThenUpdate_StateWorksCorrectly()
{
var rema = new Rema(5);
double[] history = [10, 20, 30, 40, 50];
rema.Prime(history);
double afterPrime = rema.Last.Value;
// After Prime, an isNew=true should advance the state
rema.Update(new TValue(DateTime.UtcNow, 60), isNew: true);
double afterNewBar = rema.Last.Value;
// Values should be different
Assert.NotEqual(afterPrime, afterNewBar);
// isNew=false with a different value should recalculate from previous state
rema.Update(new TValue(DateTime.UtcNow, 70), isNew: false);
double afterCorrection = rema.Last.Value;
// Correction with 70 should give different result than 60
Assert.NotEqual(afterNewBar, afterCorrection);
// isNew=false with original value (60) should restore to afterNewBar
rema.Update(new TValue(DateTime.UtcNow, 60), isNew: false);
Assert.Equal(afterNewBar, rema.Last.Value, 1e-10);
}
}