Files
wickra/examples/csharp/_common/Backtest.cs
T
kingchenc 91f6f67257 Add C# (.NET) binding over the C ABI hub (#226)
The first language stecker on the C ABI hub: a .NET binding exposing all 514
indicators as idiomatic `IDisposable` classes, generated from `wickra.h`.

## What's here

- **`bindings/csharp/`** — the `Wickra` .NET 8 package. `[LibraryImport]`
  source-generated P/Invoke (`NativeMethods.g.cs`) plus idiomatic wrappers
  (`Indicators.g.cs`), both generated from the committed `bindings/c/include/wickra.h`.
  The binding owns no indicator maths — it only marshals types across the C ABI.
- **Marshalling, verified end-to-end against the native library.** Opaque handles
  cross as `nint` kept alive per call via a `SafeHandle`; `bool` as
  `[MarshalAs(U1)]` (Rust `bool` is one byte); a self-correcting
  `DllImportResolver` validates the loaded library actually exports the Wickra
  ABI. Tests cover one representative per FFI archetype (scalar, candle, pairwise,
  multi-output, bars, profile, values-profile, order-book / array-input) plus
  exact Sma reference values.
- **NuGet packaging** — `dotnet pack` produces `Wickra.<version>.nupkg`; the
  release pipeline stages prebuilt native libraries under `runtimes/<rid>/native/`
  for six target triples (win/linux/osx × x64/arm64).
- **`examples/csharp/`** — nine examples mirroring `examples/c/`: streaming,
  backtest, multi_timeframe, parallel_assets, three strategies, and
  fetch_btcusdt + live_binance.
- **CI** — a `csharp` job on the three OSes builds the C ABI, tests the binding,
  and runs the offline examples. **Release** — a gated `csharp-publish` job packs
  and pushes to NuGet (gated on `NUGET_API_KEY`, independent of the GitHub-release
  job so a C# hiccup never blocks the C/C++ asset release).
- **Docs consistency wave** — README, CONTRIBUTING, CHANGELOG, examples/README,
  the issue / PR templates, `sync-about.yml`, and `.gitattributes`.

The native Python / Node / WASM bindings and the C ABI are untouched; this is
additive. Publishing to NuGet stays gated behind the release tag and the secret.
2026-06-09 14:32:05 +02:00

46 lines
1.9 KiB
C#

namespace Wickra.Examples;
/// <summary>Summary statistics for a long-only equity curve.</summary>
public sealed record EquityResult(double TotalReturnPct, double Sharpe, double MaxDrawdownPct, int Trades, double FinalEquity);
/// <summary>
/// Minimal long-only backtest helper: turn a stream of per-bar fractional
/// returns into a PnL / Sharpe / max-drawdown summary. The strategy examples
/// produce the returns; this aggregates them.
/// </summary>
public static class Backtest
{
/// <param name="periodReturns">Per-bar fractional returns (0.01 == +1%).</param>
/// <param name="trades">Number of position entries.</param>
/// <param name="periodsPerYear">Annualisation factor for the Sharpe ratio.</param>
public static EquityResult Summarize(IReadOnlyList<double> periodReturns, int trades, double periodsPerYear = 252.0)
{
double equity = 1.0, peak = 1.0, maxDrawdown = 0.0;
foreach (var r in periodReturns)
{
equity *= 1.0 + r;
peak = Math.Max(peak, equity);
if (peak > 0)
{
maxDrawdown = Math.Max(maxDrawdown, (peak - equity) / peak);
}
}
var mean = periodReturns.Count > 0 ? periodReturns.Average() : 0.0;
var variance = periodReturns.Count > 1
? periodReturns.Sum(x => (x - mean) * (x - mean)) / (periodReturns.Count - 1)
: 0.0;
var stdDev = Math.Sqrt(variance);
var sharpe = stdDev > 1e-12 ? mean / stdDev * Math.Sqrt(periodsPerYear) : 0.0;
return new EquityResult((equity - 1.0) * 100.0, sharpe, maxDrawdown * 100.0, trades, equity);
}
/// <summary>Prints a one-line summary.</summary>
public static void Print(string name, EquityResult r)
{
Console.WriteLine(
$"{name,-26} return={r.TotalReturnPct,8:F2}% sharpe={r.Sharpe,6:F2} maxDD={r.MaxDrawdownPct,6:F2}% trades={r.Trades}");
}
}