Refactor and optimize various components of QuanTAlib

- Removed WmaVector class to streamline weighted moving average calculations.
- Simplified RingBuffer implementation by removing unnecessary comments and improving clarity.
- Enhanced SIMD extensions for better performance and readability.
- Updated TBar and TBarSeries classes to improve property calculations and reduce overhead.
- Cleaned up TValue struct by removing redundant comments.
- Added comprehensive unit tests for IndicatorExtensions and TrimaIndicator to ensure functionality and correctness.
This commit is contained in:
Miha Kralj
2025-12-04 13:49:05 -08:00
parent 3ed35322a5
commit 967096d4f5
27 changed files with 387 additions and 3367 deletions
+3 -78
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@@ -16,7 +16,7 @@ This notebook demonstrates:
1. **Manual Data Processing**: Understanding Batch vs. Streaming modes.
2. **Streaming with `isNew`**: Handling intra-bar updates.
3. **Large Dataset Processing**: Using Geometric Brownian Motion (GBM) generated data.
4. **Vectorized Operations**: Calculating multiple EMAs simultaneously.
4. **Handling Invalid Values**: Last-value substitution for NaN/Infinity.
#!csharp
@@ -165,63 +165,9 @@ Console.WriteLine($"Streaming Last Value: {lastStreamVal.Value:F2}");
#!markdown
## 4. Vectorized EMA (Multiple Periods)
## 4. Handling Invalid Values (NaN/Infinity)
`EmaVector` allows calculating multiple EMAs (e.g., 9, 12, 26) simultaneously. This is optimized for performance using SIMD where available.
### Vectorized Batch
#!csharp
int[] periods = { 9, 12, 26 };
Console.WriteLine($"\n--- Vectorized Batch EMA (Periods: {string.Join(", ", periods)}) ---");
var emaVectorBatch = new EmaVector(periods);
var vectorBatchResults = emaVectorBatch.Calculate(closeSeries);
for (int i = 0; i < periods.Length; i++)
{
Console.WriteLine($"EMA({periods[i]}) Last Value: {vectorBatchResults[i].Last().Value:F2}");
}
#!markdown
### Vectorized Streaming
#!csharp
Console.WriteLine($"\n--- Vectorized Streaming EMA (Periods: {string.Join(", ", periods)}) ---");
var emaVectorStream = new EmaVector(periods);
TValue[] lastVectorVal = null;
foreach(var item in closeSeries)
{
lastVectorVal = emaVectorStream.Update(item);
}
for (int i = 0; i < periods.Length; i++)
{
Console.WriteLine($"EMA({periods[i]}) Last Value: {lastVectorVal[i].Value:F2}");
}
// Verification
bool allMatch = true;
for (int i = 0; i < periods.Length; i++)
{
if (Math.Abs(vectorBatchResults[i].Last().Value - lastVectorVal[i].Value) > 1e-10)
{
allMatch = false;
break;
}
}
Console.WriteLine($"\nAll Vectorized Stream/Batch values match: {allMatch}");
#!markdown
## 5. Handling Invalid Values (NaN/Infinity)
Both `Ema` and `EmaVector` use **last-value substitution** for invalid inputs. When a non-finite value (NaN, PositiveInfinity, NegativeInfinity) is encountered, it is replaced with the last valid value. This provides output continuity instead of propagating invalid values through the calculation.
`Ema` uses **last-value substitution** for invalid inputs. When a non-finite value (NaN, PositiveInfinity, NegativeInfinity) is encountered, it is replaced with the last valid value. This provides output continuity instead of propagating invalid values through the calculation.
#!csharp
@@ -271,24 +217,3 @@ for (int i = 0; i < seriesWithNaN.Count; i++)
var inputStr = double.IsFinite(input) ? input.ToString("F2") : input.ToString();
Console.WriteLine($" {inputStr,-10} → {output:F2} (IsFinite: {double.IsFinite(output)})");
}
#!csharp
Console.WriteLine("\n--- Vectorized EMA with Invalid Values ---");
int[] periodsNaN = { 5, 10 };
var emaVectorNaN = new EmaVector(periodsNaN);
// Feed values including invalid ones
var inputsNaN = new double[] { 100, 110, double.NaN, 120, double.PositiveInfinity, 130 };
var time = DateTime.Now;
foreach (var val in inputsNaN)
{
var results = emaVectorNaN.Update(new TValue(time, val));
var inputStr = double.IsFinite(val) ? val.ToString("F2") : val.ToString();
Console.WriteLine($"Input: {inputStr,-10} → EMA(5): {results[0].Value:F2}, EMA(10): {results[1].Value:F2}");
time = time.AddMinutes(1);
}
Console.WriteLine("\nAll outputs are finite - invalid inputs were substituted with last valid values.");
+5 -63
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@@ -25,30 +25,18 @@ namespace QuanTAlib;
/// </remarks>
public class Ema
{
private struct State : IEquatable<State>
private struct State
{
public double Ema;
public double E; // Compensator: decays from 1.0 to 1e-10 for bias correction
public bool IsHot; // True when 95% coverage reached (E <= 0.05)
public bool IsCompensated; // True when compensator fully decayed (E <= 1e-10)
public double E;
public bool IsHot;
public bool IsCompensated;
public static State New() => new() { Ema = 0, E = 1.0, IsHot = false, IsCompensated = false };
public readonly bool Equals(State other) =>
Ema == other.Ema && E == other.E && IsHot == other.IsHot && IsCompensated == other.IsCompensated;
public override readonly bool Equals(object? obj) =>
obj is State other && Equals(other);
public override readonly int GetHashCode() =>
HashCode.Combine(Ema, E, IsHot, IsCompensated);
public static bool operator ==(State left, State right) => left.Equals(right);
public static bool operator !=(State left, State right) => !left.Equals(right);
}
private readonly double _alpha;
private readonly double _decay; // Pre-calculated (1.0 - alpha) to avoid subtraction per tick
private readonly double _decay;
private State _state = State.New();
private State _p_state = State.New();
private double _lastValidValue;
@@ -97,9 +85,6 @@ public class Ema
/// </summary>
public bool IsHot => _state.IsHot;
/// <summary>
/// Gets a valid input value, using last-value substitution for non-finite inputs.
/// </summary>
[MethodImpl(MethodImplOptions.AggressiveInlining)]
private double GetValidValue(double input)
{
@@ -111,17 +96,9 @@ public class Ema
return _lastValidValue;
}
// 95% coverage threshold: E = 1 - 0.95 = 0.05
private const double COVERAGE_THRESHOLD = 0.05;
// Compensator decay threshold for bias correction
private const double COMPENSATOR_THRESHOLD = 1e-10;
/// <summary>
/// Core EMA calculation kernel.
/// Assumes input has already been validated via GetValidValue().
/// IsHot becomes true at 95% coverage (E <= 0.05).
/// Bias correction continues until compensator decays to 1e-10.
/// </summary>
[MethodImpl(MethodImplOptions.AggressiveInlining)]
private static double Compute(double input, double alpha, double decay, ref State state)
{
@@ -132,11 +109,9 @@ public class Ema
{
state.E *= decay;
// IsHot triggers at 95% coverage
if (!state.IsHot && state.E <= COVERAGE_THRESHOLD)
state.IsHot = true;
// Continue bias correction until compensator fully decays
if (state.E <= COMPENSATOR_THRESHOLD)
{
state.IsCompensated = true;
@@ -155,9 +130,6 @@ public class Ema
return result;
}
/// <summary>
/// Core calculation kernel that handles both batch and streaming-continuation.
/// </summary>
[MethodImpl(MethodImplOptions.AggressiveInlining)]
private static void CalculateCore(ReadOnlySpan<double> source, Span<double> output, double alpha, ref State state, ref double lastValidValue)
{
@@ -165,8 +137,6 @@ public class Ema
double decay = 1.0 - alpha;
int i = 0;
// Phase 1: Warmup with bias correction
// If state is already compensated, this loop is skipped
if (!state.IsCompensated)
{
for (; i < len && state.E > COMPENSATOR_THRESHOLD; i++)
@@ -189,7 +159,6 @@ public class Ema
state.IsCompensated = true;
}
// Phase 2: Hot loop
for (; i < len; i++)
{
double val = source[i];
@@ -203,12 +172,6 @@ public class Ema
}
}
/// <summary>
/// Updates EMA with the given value.
/// </summary>
/// <param name="input">Input value</param>
/// <param name="isNew">True for new bar, false for update to current bar (default: true)</param>
/// <returns>Compensated EMA value</returns>
[MethodImpl(MethodImplOptions.AggressiveInlining)]
public TValue Update(TValue input, bool isNew = true)
{
@@ -221,19 +184,12 @@ public class Ema
_state = _p_state;
}
// Last-value substitution: replace non-finite inputs with last valid value
double val = GetValidValue(input.Value);
val = Compute(val, _alpha, _decay, ref _state);
Value = new TValue(input.Time, val);
return Value;
}
/// <summary>
/// Updates EMA with the entire series.
/// Uses split-loop optimization: warmup phase with bias correction, then branchless hot loop.
/// </summary>
/// <param name="source">Input series</param>
/// <returns>EMA series</returns>
public TSeries Update(TSeries source)
{
if (source.Count == 0) return new TSeries(new List<long>(), new List<double>());
@@ -249,9 +205,6 @@ public class Ema
var sourceValues = source.Values;
var sourceTimes = source.Times;
// 1. Fast Batch Calculation
// Uses the unified CalculateCore to handle both new and continuing states
// Optimization: Copy state to locals to allow JIT register allocation
State state = _state;
double lastValidValue = _lastValidValue;
@@ -260,7 +213,6 @@ public class Ema
_state = state;
_lastValidValue = lastValidValue;
// Copy Times
sourceTimes.CopyTo(tSpan);
_p_state = _state;
@@ -299,15 +251,6 @@ public class Ema
Calculate(source, output, alpha);
}
/// <summary>
/// Calculates EMA in-place using alpha, writing results to pre-allocated output span.
/// Zero-allocation method for maximum performance.
/// Bias correction continues until compensator decays to 1e-10.
/// Uses split-loop optimization: warmup phase with bias correction, then branchless hot loop.
/// </summary>
/// <param name="source">Input values</param>
/// <param name="output">Output span (must be same length as source)</param>
/// <param name="alpha">Smoothing factor (0 < alpha <= 1)</param>
[MethodImpl(MethodImplOptions.AggressiveInlining)]
public static void Calculate(ReadOnlySpan<double> source, Span<double> output, double alpha)
{
@@ -318,7 +261,6 @@ public class Ema
if (source.Length == 0) return;
// Initialize default state for static calculation
State state = State.New();
double lastValid = 0;
+1 -27
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@@ -115,33 +115,9 @@ Console.WriteLine($"Last EMA: {emaOutput[^1]}");
* **Hunter's bias correction**: Same accuracy as TSeries API
* **Compatible** with `ArrayPool<T>` for buffer management
### Multi-Alpha EMA (`EmaVector`)
The `EmaVector` class is a SIMD-optimized implementation for calculating multiple EMAs with different periods on the same input series simultaneously. It leverages hardware intrinsics (AVX/SSE) for high performance.
```csharp
using QuanTAlib;
// Initialize with multiple periods
int[] periods = { 9, 12, 26 };
var emaVector = new EmaVector(periods);
// Streaming update
TValue[] results = emaVector.Update(new TValue(time, price));
// Access values
Console.WriteLine($"EMA(9): {results[0].Value}");
Console.WriteLine($"EMA(12): {results[1].Value}");
Console.WriteLine($"EMA(26): {results[2].Value}");
// Batch calculation
TSeries source = ...;
TSeries[] seriesResults = emaVector.Calculate(source);
```
### Handling Invalid Values (NaN/Infinity)
Both `Ema` and `EmaVector` use **last-value substitution** for handling invalid inputs:
`Ema` uses **last-value substitution** for handling invalid inputs:
```csharp
var ema = new Ema(10);
@@ -166,13 +142,11 @@ var results = ema.Update(series); // All values are finite
* When `NaN`, `PositiveInfinity`, or `NegativeInfinity` is encountered, the last valid value is substituted
* This provides output continuity instead of propagating invalid values
* Both scalar (`Ema`) and SIMD (`EmaVector`) implementations use identical logic
* `Reset()` clears the last valid value, so the next valid input establishes a new baseline
### Performance Characteristics
* **O(1) Complexity:** The calculation time is constant regardless of the period length.
* **SIMD Optimization:** `EmaVector` processes multiple periods in parallel using vector instructions, significantly reducing CPU cycles for multi-timeframe analysis.
* **Zero Allocation:** The streaming `Update` method is designed to be allocation-free (excluding the return struct).
## Interpretation Details
-378
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@@ -1,378 +0,0 @@
namespace QuanTAlib.Tests;
public class EmaVectorTests
{
[Fact]
public void Initialization_WithPeriods_SetsCorrectAlphas()
{
int[] periods = { 10, 20 };
var emaVector = new EmaVector(periods);
var res = emaVector.Update(new TValue(DateTime.UtcNow, 100.0));
Assert.Equal(100.0, res[0].Value, 1e-9);
Assert.Equal(100.0, res[1].Value, 1e-9);
}
[Fact]
public void Initialization_WithAlphas_Works()
{
double[] alphas = { 0.1, 0.2, 0.5 };
var emaVector = new EmaVector(alphas);
var res = emaVector.Update(new TValue(DateTime.UtcNow, 100.0));
Assert.Equal(3, res.Length);
Assert.Equal(100.0, res[0].Value, 1e-9);
Assert.Equal(100.0, res[1].Value, 1e-9);
Assert.Equal(100.0, res[2].Value, 1e-9);
}
[Fact]
public void Initialization_WithZeroPeriod_ThrowsArgumentException()
{
int[] periods = { 10, 0, 20 };
Assert.Throws<ArgumentOutOfRangeException>(() => new EmaVector(periods));
}
[Fact]
public void Initialization_WithNegativePeriod_ThrowsArgumentException()
{
int[] periods = { 10, -5, 20 };
Assert.Throws<ArgumentOutOfRangeException>(() => new EmaVector(periods));
}
[Fact]
public void Initialization_WithZeroAlpha_ThrowsArgumentException()
{
double[] alphas = { 0.1, 0.0, 0.5 };
Assert.Throws<ArgumentOutOfRangeException>(() => new EmaVector(alphas));
}
[Fact]
public void Initialization_WithNegativeAlpha_ThrowsArgumentException()
{
double[] alphas = { 0.1, -0.1, 0.5 };
Assert.Throws<ArgumentOutOfRangeException>(() => new EmaVector(alphas));
}
[Fact]
public void Initialization_WithAlphaGreaterThanOne_ThrowsArgumentException()
{
double[] alphas = { 0.1, 1.5, 0.5 };
Assert.Throws<ArgumentOutOfRangeException>(() => new EmaVector(alphas));
}
[Fact]
public void Initialization_WithAlphaEqualToOne_Works()
{
double[] alphas = { 0.1, 1.0, 0.5 };
var emaVector = new EmaVector(alphas);
var res = emaVector.Update(new TValue(DateTime.UtcNow, 100.0));
Assert.Equal(3, res.Length);
}
[Fact]
public void Calc_Streaming_MatchesSingleEma()
{
int[] periods = { 5, 10, 20 };
var emaVector = new EmaVector(periods);
var emaSingles = periods.Select(p => new Ema(p)).ToArray();
var values = new double[] { 10, 20, 30, 40, 50, 40, 30, 20, 10 };
var time = DateTime.UtcNow;
foreach (var val in values)
{
var tVal = new TValue(time, val);
var multiRes = emaVector.Update(tVal);
for (int i = 0; i < periods.Length; i++)
{
var singleRes = emaSingles[i].Update(tVal);
Assert.Equal(singleRes.Value, multiRes[i].Value, 1e-9);
Assert.Equal(singleRes.Time, multiRes[i].Time);
}
time = time.AddMinutes(1);
}
}
[Fact]
public void Calc_Series_MatchesSingleEma()
{
int[] periods = { 5, 10, 20 };
var emaVector = new EmaVector(periods);
var emaSingles = periods.Select(p => new Ema(p)).ToArray();
int len = 100;
var t = new System.Collections.Generic.List<long>(len);
var v = new System.Collections.Generic.List<double>(len);
var now = DateTime.UtcNow;
for (int i = 0; i < len; i++)
{
t.Add(now.AddMinutes(i).Ticks);
v.Add(Math.Sin(i * 0.1) * 100);
}
var series = new TSeries(t, v);
var multiRes = emaVector.Calculate(series);
for (int i = 0; i < periods.Length; i++)
{
var singleRes = emaSingles[i].Update(series);
Assert.Equal(singleRes.Count, multiRes[i].Count);
for (int j = 0; j < len; j++)
{
Assert.Equal(singleRes.Values[j], multiRes[i].Values[j], 1e-8);
}
}
}
[Fact]
public void Calc_Series_MatchesStreaming()
{
int[] periods = { 5, 10, 20 };
var emaVectorBatch = new EmaVector(periods);
var emaVectorStream = new EmaVector(periods);
int len = 100;
var t = new System.Collections.Generic.List<long>(len);
var v = new System.Collections.Generic.List<double>(len);
var now = DateTime.UtcNow;
for (int i = 0; i < len; i++)
{
t.Add(now.AddMinutes(i).Ticks);
v.Add(Math.Sin(i * 0.1) * 100);
}
var series = new TSeries(t, v);
var batchRes = emaVectorBatch.Calculate(series);
for (int i = 0; i < len; i++)
{
var tVal = new TValue(new DateTime(t[i], DateTimeKind.Utc), v[i]);
var streamRes = emaVectorStream.Update(tVal);
for (int j = 0; j < periods.Length; j++)
{
Assert.Equal(batchRes[j].Values[i], streamRes[j].Value, 1e-9);
}
}
}
[Fact]
public void Calculate_Static_MatchesInstanceMethod()
{
int[] periods = { 5, 10, 20 };
int len = 50;
var t = new System.Collections.Generic.List<long>(len);
var v = new System.Collections.Generic.List<double>(len);
var now = DateTime.UtcNow;
for (int i = 0; i < len; i++)
{
t.Add(now.AddMinutes(i).Ticks);
v.Add(Math.Sin(i * 0.1) * 100);
}
var series = new TSeries(t, v);
var instanceEma = new EmaVector(periods);
var instanceRes = instanceEma.Calculate(series);
var staticRes = EmaVector.Calculate(series, periods);
for (int i = 0; i < periods.Length; i++)
{
Assert.Equal(instanceRes[i].Count, staticRes[i].Count);
for (int j = 0; j < len; j++)
{
Assert.Equal(instanceRes[i].Values[j], staticRes[i].Values[j], 1e-9);
}
}
}
[Fact]
public void Reset_ClearsState()
{
int[] periods = { 10 };
var emaVector = new EmaVector(periods);
emaVector.Update(new TValue(DateTime.UtcNow, 100.0));
emaVector.Reset();
var res = emaVector.Update(new TValue(DateTime.UtcNow, 200.0));
Assert.Equal(200.0, res[0].Value, 1e-9);
}
[Fact]
public void Update_NaN_Input_UsesLastValidValue()
{
int[] periods = { 10, 20 };
var emaVector = new EmaVector(periods);
emaVector.Update(new TValue(DateTime.UtcNow, 100.0));
emaVector.Update(new TValue(DateTime.UtcNow, 110.0));
var resultAfterNaN = emaVector.Update(new TValue(DateTime.UtcNow, double.NaN));
foreach (var result in resultAfterNaN)
{
Assert.True(double.IsFinite(result.Value), $"Expected finite value but got {result.Value}");
}
}
[Fact]
public void Update_Infinity_Input_UsesLastValidValue()
{
int[] periods = { 10, 20 };
var emaVector = new EmaVector(periods);
emaVector.Update(new TValue(DateTime.UtcNow, 100.0));
emaVector.Update(new TValue(DateTime.UtcNow, 110.0));
var resultAfterPosInf = emaVector.Update(new TValue(DateTime.UtcNow, double.PositiveInfinity));
foreach (var result in resultAfterPosInf)
{
Assert.True(double.IsFinite(result.Value));
}
var resultAfterNegInf = emaVector.Update(new TValue(DateTime.UtcNow, double.NegativeInfinity));
foreach (var result in resultAfterNegInf)
{
Assert.True(double.IsFinite(result.Value));
}
}
[Fact]
public void Update_MultipleNaN_ContinuesWithLastValid()
{
int[] periods = { 5, 10 };
var emaVector = new EmaVector(periods);
emaVector.Update(new TValue(DateTime.UtcNow, 100.0));
emaVector.Update(new TValue(DateTime.UtcNow, 110.0));
emaVector.Update(new TValue(DateTime.UtcNow, 120.0));
var r1 = emaVector.Update(new TValue(DateTime.UtcNow, double.NaN));
var r2 = emaVector.Update(new TValue(DateTime.UtcNow, double.NaN));
var r3 = emaVector.Update(new TValue(DateTime.UtcNow, double.NaN));
foreach (var result in r1) Assert.True(double.IsFinite(result.Value));
foreach (var result in r2) Assert.True(double.IsFinite(result.Value));
foreach (var result in r3) Assert.True(double.IsFinite(result.Value));
}
[Fact]
public void Calculate_Series_HandlesNaN()
{
int[] periods = { 5, 10 };
var emaVector = new EmaVector(periods);
var t = new System.Collections.Generic.List<long>();
var v = new System.Collections.Generic.List<double>();
var now = DateTime.UtcNow;
t.Add(now.Ticks); v.Add(100.0);
t.Add(now.AddMinutes(1).Ticks); v.Add(110.0);
t.Add(now.AddMinutes(2).Ticks); v.Add(double.NaN);
t.Add(now.AddMinutes(3).Ticks); v.Add(120.0);
t.Add(now.AddMinutes(4).Ticks); v.Add(double.PositiveInfinity);
t.Add(now.AddMinutes(5).Ticks); v.Add(130.0);
var series = new TSeries(t, v);
var results = emaVector.Calculate(series);
foreach (var periodResults in results)
{
foreach (var val in periodResults.Values)
{
Assert.True(double.IsFinite(val), $"Expected finite value but got {val}");
}
}
}
[Fact]
public void Reset_ClearsLastValidValue()
{
int[] periods = { 10 };
var emaVector = new EmaVector(periods);
emaVector.Update(new TValue(DateTime.UtcNow, 100.0));
emaVector.Update(new TValue(DateTime.UtcNow, double.NaN));
emaVector.Reset();
var result = emaVector.Update(new TValue(DateTime.UtcNow, 50.0));
Assert.Equal(50.0, result[0].Value, 1e-9);
}
[Fact]
public void NaN_Handling_MatchesSingleEma()
{
int[] periods = { 5, 10, 20 };
var emaVector = new EmaVector(periods);
var emaSingles = periods.Select(p => new Ema(p)).ToArray();
var values = new double[] { 10, 20, double.NaN, 40, double.PositiveInfinity, 60, 70 };
var time = DateTime.UtcNow;
foreach (var val in values)
{
var tVal = new TValue(time, val);
var multiRes = emaVector.Update(tVal);
for (int i = 0; i < periods.Length; i++)
{
var singleRes = emaSingles[i].Update(tVal);
Assert.Equal(singleRes.Value, multiRes[i].Value, 1e-9);
}
time = time.AddMinutes(1);
}
}
[Fact]
public void Values_Property_UpdatesAfterUpdate()
{
int[] periods = { 5, 10 };
var emaVector = new EmaVector(periods);
var result = emaVector.Update(new TValue(DateTime.UtcNow, 100.0));
Assert.Equal(result[0].Value, emaVector.Values[0].Value);
Assert.Equal(result[1].Value, emaVector.Values[1].Value);
}
[Fact]
public void Values_Property_UpdatesAfterCalculate()
{
int[] periods = { 5, 10 };
var emaVector = new EmaVector(periods);
var t = new System.Collections.Generic.List<long> { 100, 200, 300 };
var v = new System.Collections.Generic.List<double> { 10.0, 20.0, 30.0 };
var series = new TSeries(t, v);
var results = emaVector.Calculate(series);
Assert.Equal(results[0].Last.Value, emaVector.Values[0].Value, 1e-9);
Assert.Equal(results[1].Last.Value, emaVector.Values[1].Value, 1e-9);
}
}
-327
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@@ -1,327 +0,0 @@
using System.Numerics;
using System.Runtime.CompilerServices;
using System.Runtime.InteropServices;
namespace QuanTAlib;
/// <summary>
/// Multi-Alpha Exponential Moving Average (EMA) - SIMD optimized.
/// Calculates multiple EMAs with different periods/alphas for the same input series in parallel.
/// Uses last-value substitution for invalid inputs (NaN/Infinity).
/// </summary>
[SkipLocalsInit]
public class EmaVector
{
private readonly double[] _alphas;
private readonly double[] _emas;
private readonly double[] _Es;
private readonly double[] _p_emas;
private readonly double[] _p_Es;
private readonly int _count;
private double _lastValidValue;
/// <summary>
/// Current EMA values for all periods.
/// </summary>
public ReadOnlySpan<TValue> Values => _values;
private readonly TValue[] _values;
/// <summary>
/// Initializes EmaVector with specified periods.
/// </summary>
/// <param name="periods">Array of periods</param>
public EmaVector(int[] periods)
{
_count = periods.Length;
_alphas = new double[_count];
_emas = new double[_count];
_Es = new double[_count];
_p_emas = new double[_count];
_p_Es = new double[_count];
_values = new TValue[_count];
for (int i = 0; i < _count; i++)
{
ArgumentOutOfRangeException.ThrowIfLessThanOrEqual(periods[i], 0);
_alphas[i] = 2.0 / (periods[i] + 1);
ResetAt(i);
}
}
/// <summary>
/// Initializes EmaVector with specified alphas.
/// </summary>
/// <param name="alphas">Array of alphas</param>
public EmaVector(double[] alphas)
{
_count = alphas.Length;
_alphas = new double[_count];
_emas = new double[_count];
_Es = new double[_count];
_p_emas = new double[_count];
_p_Es = new double[_count];
_values = new TValue[_count];
for (int i = 0; i < _count; i++)
{
if (alphas[i] <= 0 || alphas[i] > 1)
throw new ArgumentOutOfRangeException(nameof(alphas), alphas[i], "Alpha must be between 0 (exclusive) and 1 (inclusive)");
_alphas[i] = alphas[i];
ResetAt(i);
}
}
private void ResetAt(int index)
{
_emas[index] = 0.0;
_Es[index] = 1.0;
}
/// <summary>
/// Gets a valid input value, using last-value substitution for non-finite inputs.
/// </summary>
[MethodImpl(MethodImplOptions.AggressiveInlining)]
private double GetValidValue(double input)
{
if (double.IsFinite(input))
{
_lastValidValue = input;
return input;
}
return _lastValidValue;
}
/// <summary>
/// Resets all EMA states.
/// </summary>
public void Reset()
{
for (int i = 0; i < _count; i++)
{
ResetAt(i);
}
_lastValidValue = 0;
Array.Clear(_values);
}
/// <summary>
/// Updates EMAs with the given value.
/// Uses last-value substitution: invalid inputs (NaN/Infinity) are replaced with
/// the last known good value, providing continuity in the output series.
/// </summary>
/// <param name="input">Input value</param>
/// <param name="isNew">True for new bar, false for update to current bar (default: true)</param>
/// <returns>Array of compensated EMA values</returns>
[MethodImpl(MethodImplOptions.AggressiveInlining)]
public TValue[] Update(TValue input, bool isNew = true)
{
if (isNew)
{
Array.Copy(_emas, _p_emas, _count);
Array.Copy(_Es, _p_Es, _count);
}
else
{
Array.Copy(_p_emas, _emas, _count);
Array.Copy(_p_Es, _Es, _count);
}
// Last-value substitution: replace non-finite inputs with last valid value
double val = GetValidValue(input.Value);
// SIMD Loop
int vecCount = Vector<double>.Count;
int i = 0;
if (Vector.IsHardwareAccelerated && _count >= vecCount)
{
var vecInput = new Vector<double>(val);
var vecOne = Vector<double>.One;
var vecEpsilon = new Vector<double>(1e-10);
for (; i <= _count - vecCount; i += vecCount)
{
// Load state
var vecAlpha = new Vector<double>(_alphas, i);
var vecEma = new Vector<double>(_emas, i);
var vecE = new Vector<double>(_Es, i);
// Update EMA
// ema += alpha * (input - ema)
vecEma += vecAlpha * (vecInput - vecEma);
// Update E (warmup factor)
// E *= (1 - alpha)
vecE *= (vecOne - vecAlpha);
// Calculate compensated result
// res = ema / (1 - E)
var vecCompensated = vecEma / (vecOne - vecE);
// Check warmup condition: E <= 1e-10 means "hot" (use raw EMA)
// Vector.LessThanOrEqual returns Vector<long> with all-1s for true, all-0s for false
// We reinterpret as Vector<double> for use with ConditionalSelect
var isHotMask = Vector.LessThanOrEqual(vecE, vecEpsilon);
// Select result: if hot (E <= epsilon), use raw EMA; otherwise use compensated
// ConditionalSelect: mask=true -> first arg, mask=false -> second arg
var vecResult = Vector.ConditionalSelect(
Vector.AsVectorDouble(isHotMask),
vecEma, // Hot: use raw EMA
vecCompensated // Cold: use compensated
);
// Store state
vecEma.CopyTo(_emas, i);
vecE.CopyTo(_Es, i);
// Store result
for (int j = 0; j < vecCount; j++)
{
_values[i + j] = new TValue(input.Time, vecResult[j]);
}
}
}
// Scalar fallback for remaining items
for (; i < _count; i++)
{
double alpha = _alphas[i];
_emas[i] += alpha * (val - _emas[i]);
double result = _emas[i];
if (_Es[i] > 1e-10)
{
_Es[i] *= (1.0 - alpha);
if (_Es[i] > 1e-10)
{
result = _emas[i] / (1.0 - _Es[i]);
}
}
_values[i] = new TValue(input.Time, result);
}
return _values;
}
/// <summary>
/// Calculates EMAs for the entire series.
/// </summary>
/// <param name="source">Input series</param>
/// <returns>Array of EMA series</returns>
public TSeries[] Calculate(TSeries source)
{
int len = source.Count;
var resultSeries = new TSeries[_count];
// Pre-allocate lists
var tLists = new List<long>[_count];
var vLists = new List<double>[_count];
for (int i = 0; i < _count; i++)
{
tLists[i] = new List<long>(len);
vLists[i] = new List<double>(len);
CollectionsMarshal.SetCount(tLists[i], len);
CollectionsMarshal.SetCount(vLists[i], len);
}
var sourceValues = source.Values;
var sourceTimes = source.Times;
int vecCount = Vector<double>.Count;
var vecOne = Vector<double>.One;
var vecEpsilon = new Vector<double>(1e-10);
for (int t = 0; t < len; t++)
{
double val = sourceValues[t];
long time = sourceTimes[t];
// Last-value substitution: replace non-finite inputs with last valid value
val = GetValidValue(val);
var vecInput = new Vector<double>(val);
int i = 0;
if (Vector.IsHardwareAccelerated && _count >= vecCount)
{
for (; i <= _count - vecCount; i += vecCount)
{
var vecAlpha = new Vector<double>(_alphas, i);
var vecEma = new Vector<double>(_emas, i);
var vecE = new Vector<double>(_Es, i);
vecEma += vecAlpha * (vecInput - vecEma);
vecE *= (vecOne - vecAlpha);
var vecCompensated = vecEma / (vecOne - vecE);
// Check warmup condition: E <= 1e-10 means "hot" (use raw EMA)
var isHotMask = Vector.LessThanOrEqual(vecE, vecEpsilon);
// Select result: if hot, use raw EMA; otherwise use compensated
var vecResult = Vector.ConditionalSelect(
Vector.AsVectorDouble(isHotMask),
vecEma, // Hot: use raw EMA
vecCompensated // Cold: use compensated
);
vecEma.CopyTo(_emas, i);
vecE.CopyTo(_Es, i);
// Scatter results to lists
for (int j = 0; j < vecCount; j++)
{
CollectionsMarshal.AsSpan(tLists[i + j])[t] = time;
CollectionsMarshal.AsSpan(vLists[i + j])[t] = vecResult[j];
}
}
}
for (; i < _count; i++)
{
double alpha = _alphas[i];
_emas[i] += alpha * (val - _emas[i]);
double result = _emas[i];
if (_Es[i] > 1e-10)
{
_Es[i] *= (1.0 - alpha);
if (_Es[i] > 1e-10)
{
result = _emas[i] / (1.0 - _Es[i]);
}
}
CollectionsMarshal.AsSpan(tLists[i])[t] = time;
CollectionsMarshal.AsSpan(vLists[i])[t] = result;
}
}
// Create TSeries and update Values
for (int i = 0; i < _count; i++)
{
resultSeries[i] = new TSeries(tLists[i], vLists[i]);
var lastT = CollectionsMarshal.AsSpan(tLists[i])[len - 1];
var lastV = CollectionsMarshal.AsSpan(vLists[i])[len - 1];
_values[i] = new TValue(lastT, lastV);
}
return resultSeries;
}
/// <summary>
/// Calculates EMAs for the entire series using specified periods.
/// </summary>
/// <param name="source">Input series</param>
/// <param name="periods">Array of periods</param>
/// <returns>Array of EMA series</returns>
public static TSeries[] Calculate(TSeries source, int[] periods)
{
var emaVector = new EmaVector(periods);
return emaVector.Calculate(source);
}
}