Version bump 0.8.2 → 0.8.3, releasing the per-binding throughput benchmark work
(merged in #246).
Bumped via `ScriptHelpers/bump_version.py` across all manual touchpoints —
`Cargo.toml`, `pyproject.toml`, the Node `package.json` + 6 platform packages +
both lockfiles, the Java `pom.xml`s + README, the C# `.csproj`, the R
`DESCRIPTION` — plus `Cargo.lock` (via `cargo build`) and the `CHANGELOG.md`
`[0.8.3]` section and compare URLs.
CHANGELOG `[0.8.3]`:
- Per-binding throughput benchmarks for all 9 targets (BENCHMARKS.md §3).
- C ABI archetype test (`examples/c/archetypes.c`).
`cargo fmt`, `cargo test --workspace --all-features` (all green) and
`cargo clippy --workspace --all-targets --all-features -D warnings` pass. The
docs/webpage version strings are bumped by `sync-about.yml` on the `v*` tag —
not touched here.
Adds a `throughput` benchmark to every target and closes two small
test-coverage documentation/QA gaps. One PR, no merge of binding code beyond
the additive benchmarks and one C test.
## 1. Per-binding throughput benchmarks (all 9 targets)
Each benchmark feeds a deterministic synthetic OHLCV series through three
indicators chosen by **FFI call-signature archetype** (not algorithm — the same
Rust core runs underneath all bindings):
- `SMA(20)` — 1-in → 1-out (baseline boundary cost)
- `ATR(14)` — multi-in → 1-out (input marshalling)
- `MACD(12,26,9)` — 1-in → multi-out (output marshalling)
Streaming is timed for all three; batch for the single-output SMA and ATR
(median of 3 runs, after a warmup pass).
New: Python (PyO3), WASM, C (CMake), C# (Stopwatch), Go, Java (FFM), R, and the
Rust core baseline (`examples/rust/.../throughput.rs`, **no FFI** — the ceiling
the bindings are measured against and the value their batch paths converge
towards). Node already had `throughput.js`.
**Not a speed claim:** there is no comparable streaming TA library for C, C#,
Go, Java, R or WASM to compare against, so these are raw per-binding throughput
numbers documenting each language's FFI overhead — see BENCHMARKS.md §3. The
"Wickra is fast" claim still lives in §1/§2 (Rust core + the Python/Rust
cross-library runs).
## 2. README `## Testing`: C# and C bullets
The section listed every layer except C# and C, even though both have suites.
Adds the two missing bullets.
## 3. C archetype ctest
`examples/c/archetypes.c` drives one indicator per FFI archetype through the
real C boundary (scalar + batch==streaming, multi-output, bars, profile, array
input) plus reset, invalid-parameter and NULL-safety — the C counterpart of the
Go/R/Java archetype suites. Runs on three OSes via the existing CMake/ctest.
## Notes
- Benchmarks are not CI-gated (manual-run scripts, like the existing
`throughput.js`); no `ci.yml`/`release.yml` changes.
- Docs: BENCHMARKS.md §3, a `## Benchmark` section in every binding README, a
CHANGELOG entry.
- Verified locally by running: Rust, Python, C, C#, Go, Java (real numbers); the
C archetype ctest with `-Wall -Wextra -Wpedantic -Werror`. WASM and R are
API-correct and syntax-checked but need their own toolchains to run.
Patch release shipping the R WebAssembly build fix (#244): `bindings/r/configure` builds the C ABI from source for `wasm32-unknown-emscripten`, so r-universe's webR build stops failing. Also carries the shared Go badge in `bindings/go/README.md`. Version bumped across all manual touchpoints via `bump_version.py` (incl. DESCRIPTION + csproj, which had drifted before).
Patch release shipping the wickra-go mirror license fix (#239). The release-time Go mirror now includes the dual MIT OR Apache-2.0 license files, so the next published Go module version resolves with a redistributable license on pkg.go.dev. No code changes; all other packages are republished unchanged at 0.8.1.
Bumps the workspace from 0.7.9 to 0.8.0 and adds the release-time mirror of the Go module to a standalone `wickra-go` repository.
## release.yml: `go-mirror` job
Adds a `go-mirror` job (independent of `github-release`, `needs: c-abi-build`) that on every `v*` tag:
- assembles the standalone Go module from `bindings/go` (single-package source + the vendored `include/wickra.h`),
- stages the six prebuilt C ABI libraries from the `c-abi-build` artifacts under `lib/<goos>_<goarch>/` (committed in the mirror, unlike the in-repo `lib/.gitignore`),
- rewrites `go.mod` to `module github.com/wickra-lib/wickra-go`,
- commits and tags the result in `wickra-lib/wickra-go` using the `WICKRA_GO_MIRROR_TOKEN` fine-grained PAT.
This makes `go get github.com/wickra-lib/wickra-go` build with no extra steps, closing the gap where the in-repo `bindings/go` module only built inside a full repository checkout. The mirror is a derived artifact, so its bot commit is intentionally unsigned.
## Version bump 0.7.9 -> 0.8.0
Patch never reaches double digits (`0.7.9` -> `0.8.0`). Touchpoints: `Cargo.toml` (+ `Cargo.lock` via build), `bindings/python/pyproject.toml`, `bindings/node/package.json` + 6 platform `npm/*/package.json` + both `package-lock.json` files, `bindings/java/pom.xml` + `examples/java/pom.xml` + Maven/Gradle snippets in `bindings/java/README.md`, and `CHANGELOG.md`. The C# `Wickra.csproj` (version set per tag) and `bindings/c` (inherits the workspace version) are intentionally untouched.
Tagging `v0.8.0` (which triggers the publish + the new mirror) stays gated on explicit confirmation.
Adds a Java binding (`bindings/java`) over the C ABI hub — the fourth language stecker after C#, Go and R, reaching the hub through the Java Foreign Function & Memory API (Panama, `java.lang.foreign`, final in Java 22) rather than JNI or jextract.
## What's here
- **`bindings/java`** — a Maven module (`org.wickra:wickra`) exposing all 514 indicators as idiomatic `AutoCloseable` classes. The downcall handles (`internal/NativeMethods.java`), the per-indicator wrappers and the output records are generated from `bindings/c/include/wickra.h` (same eight-archetype taxonomy as the C#/Go/R generators: scalar/batch, multi-output, bars, profile, values-profile, array-input). The opaque handle is a `MemorySegment` freed by a registered `java.lang.ref.Cleaner` action; multi-output returns a `record` (`null` at warmup), bars a `record[]`, profiles a record with a trailing `double[]`. The hand-written `WickraNative` resolves the native library (a bundled per-platform copy, or a `target/release` fallback for local development) and validates it against a sentinel symbol. repr(C) struct offsets are computed in the generator so the FFM reads land on the exact bytes.
- **`examples/java`** — the full example suite mirroring C/C#/Go/R: streaming, backtest, multi_timeframe, parallel_assets (parallel streams), three strategies, and `FetchBtcusdt`/`LiveBinance`.
- **CI** — a `java` job builds the C ABI library, sets up JDK 22 (Temurin, with a CDN-flake retry), runs the archetype test suite and the seven offline examples on Linux, macOS and Windows.
- **Release** — a gated `java-publish` job (skipped until the `JAVA_PUBLISH_ENABLED` repository variable is set) stages the native libraries from the `wickra-c-<triple>.tar.gz` assets into the binding's resources and deploys to Maven Central with GPG signing. Independent of the GitHub-release job, like the NuGet job.
- **Docs** — Java added to the README languages table, project layout, building/testing and comparison table, CONTRIBUTING, ARCHITECTURE, the examples index, the issue/PR templates, the About-description template, and the other binding READMEs.
## Requirements
Java 22+ (the FFM API is final since Java 22). The binding requires `--enable-native-access=ALL-UNNAMED` at runtime; the test and example runners pass it automatically.
No Rust crate or `Cargo.toml` change — the Java binding is standalone and additive. The generated `*.java` are committed (like the node `index.js`/`index.d.ts`); the generator stays private.
Adds an R binding (`bindings/r`) over the C ABI hub — the third language stecker after C# and Go, reaching the hub through R's native `.Call` interface (not extendr).
## What's here
- **`bindings/r`** — an R package exposing all 514 indicators as constructors that return a `wickra_indicator` object with generic `update`/`batch`/`reset` methods. The C glue (`src/wickra.c`) and R wrappers (`R/indicators.R`) are generated from `bindings/c/include/wickra.h` (same archetype taxonomy as the C#/Go generators: scalar/batch, multi-output, bars, profile, profile-values, array-input). The opaque handle is an R external pointer freed by a registered finalizer; multi-output returns a named vector (`NA` at warmup), bars a matrix, profiles a list.
- **`examples/r`** — the full example suite mirroring C/C#/Go: streaming, backtest, multi_timeframe, parallel_assets (`mclapply`), three strategies, and `fetch_btcusdt`/`live_binance`.
- **CI** — an `r` job builds the C ABI library, installs the package, runs the `testthat` suite and the offline examples on Linux, macOS and Windows (`R CMD check` is clean: 0 warnings, 0 notes).
- **Docs** — R added to the README languages table, project layout, building/testing, CONTRIBUTING binding table + regenerate note, ARCHITECTURE, examples index, issue/PR templates, the About-description template, and the other binding READMEs.
## Linking / distribution
The package compiles a thin `.Call` glue layer against the prebuilt C ABI library (header via `WICKRA_INCLUDE_DIR`, library via `WICKRA_LIB_DIR`). On Windows the package's own `wickra.dll` would collide with the C ABI's `wickra.dll`, so `configure.win` stages a renamed copy (`wickra_abi.dll`) and builds an import library referencing it; `install.libs.R` bundles the DLL and `.onLoad` puts it on the load path. On Linux/macOS the rpath locates the shared library. No `release.yml` change — R is distributed via r-universe / source install (gated).
No Rust crate or `Cargo.toml` change — the R package is standalone and additive.
Adds a Go binding (`bindings/go`) over the C ABI hub — the second language stecker after C#.
## What's here
- **`bindings/go`** — a cgo binding exposing all 514 indicators as idiomatic Go types with `New<Indicator>` constructors and `Update`/`Batch`/`Reset`/`Close` methods. The wrappers in `indicators_gen.go` are generated from `bindings/c/include/wickra.h` (same archetype taxonomy as the C# generator: scalar/batch, multi-output, bars, profile, profile-values, array-input). Opaque handles are freed by `Close()` with a `runtime.SetFinalizer` backstop; pointer arguments are caller-owned, panics never cross the boundary.
- **`examples/go`** — the full example suite mirroring C/C#: streaming, backtest, multi_timeframe, parallel_assets (goroutine fan-out), three strategies, and `fetch_btcusdt`/`live_binance`.
- **CI** — a `go` job builds the C ABI library, stages it, and runs `gofmt`/`go vet`/`go test` plus the offline examples on Linux, macOS and Windows.
- **Docs** — Go added to the README languages table, project layout, building/testing, CONTRIBUTING binding table + regenerate note, ARCHITECTURE, examples index, issue/PR templates, the About-description template, and the other binding READMEs.
## Linking / distribution
The binding links the prebuilt C ABI library via cgo (`libwickra.so`/`.dylib`/`wickra.dll` staged under `bindings/go/lib`, gitignored). The native libraries are already shipped per target triple by the existing `c-abi-build` release job; distribution is via the subdirectory module tag `bindings/go/vX.Y.Z` (gated), so `release.yml` needs no new publish job.
No Rust crate or `Cargo.toml` change — the Go module is standalone and additive.
Not for merge yet (gated, per request).
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.
Stacked on #222 (base `feat/c-abi-hub`), so the diff is just the additions on top of the hub foundation — no merge of #222 required.
## What this adds
**Examples — full parity with rust/python/node (`examples/c/`)**
- `streaming.c` upgraded to the multi-indicator (SMA/EMA/RSI/MACD + signals) demo
- `backtest.c`, `multi_timeframe.c` (manual time-bucket resampling), `parallel_assets.c` (serial vs OpenMP fan-out, one handle per asset)
- three educational strategies: `strategy_rsi_mean_reversion.c`, `strategy_macd_adx.c`, `strategy_bollinger_squeeze.c`
- two network examples shelling out to `curl`: `fetch_btcusdt.c`, `live_binance.c` (REST poll)
- two header-only helpers (`wickra_csv.h`, `wickra_strategy.h`) since the C ABI ships no IO layer
- CMake builds all 11; the 9 offline ones run under `ctest` on 3 OS; the network two are built-only
**Docs & metadata — surface the C ABI everywhere it was missing**
- ARCHITECTURE diagram + crate table, SECURITY + THREAT_MODEL (the C ABI as the sole `unsafe` FFI surface), the three binding package READMEs, issue/PR templates, CHANGELOG, and the GitHub About template (live About + org description updated too)
**Cleanup**
- removed all references to the private generator tooling from public files (`bindings/c/src/lib.rs` header, `CONTRIBUTING.md`, `sync-about.yml`)
Verified locally: `cargo build -p wickra-c --release`, `cmake + ctest` (9/9 pass), and `-Wall -Wextra -Wpedantic` clean on gcc 13.
Version bump **0.7.3 → 0.7.4** for the B19 Alt-Chart Bars batch (7 new bar builders, 507 → 514).
Bumps `Cargo.toml` (+ `wickra-core` dep), `Cargo.lock`, `pyproject.toml`, the Node `package.json` and its six platform packages, both `package-lock.json` files, and the CHANGELOG (`[Unreleased]` → `[0.7.4]` with compare URLs).
Version bump **0.7.2 → 0.7.3** for the B18 Risk / Performance batch (9 new indicators, 498 → 507).
Bumps `Cargo.toml` (+ `wickra-core` dep), `Cargo.lock`, `pyproject.toml`, the Node `package.json` and its six platform packages, both `package-lock.json` files, and the CHANGELOG (`[Unreleased]` → `[0.7.3]` with compare URLs).
B13 of the family-deepening roadmap — five alternative-chart indicators (474 -> 479), all in the **Ichimoku & Charts** family.
- **Smoothed Heikin-Ashi** (`candle -> struct {open, high, low, close}`) — a Heikin-Ashi candle computed from EMA-smoothed OHLC.
- **Heikin-Ashi Oscillator** (`candle -> f64`) — the HA body (`ha_close - ha_open`), optionally EMA-smoothed, as a zero-line oscillator.
- **Three Line Break** (`candle -> f64`) — line-break ("kakushi") chart trend direction; reverses only when the close breaks the extreme of the last N lines. Distinct from the candlestick `ThreeLineStrike`.
- **Equivolume** (`candle -> struct {height, width}`) — a box whose height is the bar range and width is volume-relative.
- **CandleVolume** (`candle -> struct {body, width}`) — a candle whose body is close-minus-open and width is volume-relative.
All bindings hand-written (3 struct-output + 2 candle-input-with-open / non-period-ctor). Wiring complete across core, Python, Node, WASM, fuzz, tests, README + docs counter (479) and CHANGELOG. Verified: core 3915 + doc 432, clippy clean, node 554, python 913.
Adds five support/resistance and pivot indicators, growing the catalog 462 -> 467.
## Indicators
- **CentralPivotRange** (Candle -> struct) — the classic pivot `(H+L+C)/3` flanked by two central levels (TC/BC); range width gauges trending vs balanced days.
- **MurreyMathLines** (Candle -> struct) — T. H. Murrey's eighths grid over a rolling high-low frame; nine levels (0/8 .. 8/8) acting as support/resistance.
- **AndrewsPitchfork** (Candle -> struct) — median line and two parallels projected forward from the last three auto-detected swing pivots (symmetric fractal of half-width `strength`).
- **VolumeWeightedSr** (Candle -> struct) — a band whose edges are the volume-weighted average of recent highs (resistance) and lows (support); falls back to equal weighting when window volume is zero.
- **PivotReversal** (Candle -> f64) — a `+1`/`-1` breakout signal fired on the bar where price closes through the most recently confirmed swing pivot.
## Wiring
Core structs with branch-complete unit tests, Python/Node/WASM bindings, fuzz drives, reference + streaming-vs-batch tests, README + docs counter sync (FAMILIES "Pivots & S/R"), and CHANGELOG entries.
Verified locally: `cargo fmt`, `cargo test -p wickra-core` (3798 lib + 425 doc), `cargo clippy --workspace --all-targets --all-features -D warnings`, `npm run build && npm test` (542), `maturin develop` + `pytest` (891).
Version bump for the **v0.6.5** release shipping the **B10 Ehlers / Cycle** family (#199): 452 -> 462 indicators. Bumps workspace + Python/Node/WASM package versions, lockfiles and CHANGELOG. No code changes.
Version bump for the **v0.6.4** release shipping the **B9 Price Statistics** family (#197): 447 -> 452 indicators. Bumps workspace + Python/Node/WASM package versions, lockfiles and CHANGELOG. No code changes.
Deepens the **Price Statistics** family (B9) with five rolling-statistics indicators (447 -> 452):
- **ShannonEntropy** — Shannon entropy of a binned rolling value distribution.
- **SampleEntropy** — Richman-Moorman sample entropy (regularity/complexity of a window).
- **KendallTau** — Kendall rank correlation (tau-b) over paired observations (pairwise; distinct from Pearson/Spearman).
- **JarqueBera** — Jarque-Bera normality test statistic over a rolling window.
- **RollingMinMaxScaler** — maps the latest value to 0..1 over a rolling window.
All scalar f64 input except KendallTau (pairwise). Multi-arg scalars (Shannon/Sample entropy) use hand-written Python/Node bindings + the variadic wasm macro; KendallTau uses the pair macros. Verified locally: 3668 core lib + 410 doc tests, clippy clean, 527 node tests, 871 pytest, counter 452.
Version bump for the **v0.6.3** release shipping the **B8 Volume** family (#195): 440 -> 447 indicators. Bumps workspace + Python/Node/WASM package versions, lockfiles and CHANGELOG. No code changes.
Deepens the **Volume** family (B8) with seven indicators (440 -> 447):
- **VolumeRsi** — Wilder RSI computed on signed volume flow.
- **WilliamsAd** — Williams Accumulation/Distribution cumulative line (distinct from Chaikin A/D).
- **TwiggsMoneyFlow** — true-range volume accumulation with Wilder smoothing (distinct from CMF).
- **TradeVolumeIndex** — tick-direction volume accumulation past a min-tick threshold (distinct from TSV).
- **IntradayIntensity** — volume weighted by close position within the bar range.
- **BetterVolume** — VSA volume-vs-spread effort/result classifier.
- **VolumeWeightedMacd** — MACD computed on VWMA with signal line and histogram (struct output).
("Up/Down Volume Ratio" already ships from A2.) All Candle input; the six scalar stops emit f64, VolumeWeightedMacd a {macd, signal, histogram} struct. Hand-written Python/Node/WASM bindings for the volume signature. Verified locally: 3620 core lib + 405 doc tests, clippy clean, 522 node tests, 865 pytest, counter 447.
Version bump for the **v0.6.2** release shipping the **B7 Trailing Stops** family (#193): 434 -> 440 indicators.
Bumps workspace + Python/Node/WASM package versions, lockfiles and CHANGELOG (cuts the `[0.6.2]` section). No code changes.
Adds the **Trailing Stops** family deepening (B7), six new indicators (434 -> 440):
- **KaseDevStop** — Cynthia Kase's volatility stop on the standard deviation of the two-bar true range.
- **ElderSafeZone** — Alexander Elder's stop offset by a multiple of average market noise.
- **AtrRatchet** — Kaufman ATR ratchet that tightens its multiple by a per-bar increment.
- **Nrtr** — Nick Rypock Trailing Reverse (percentage band).
- **TimeBasedStop** — exits after a fixed number of bars (scalar fraction of elapsed life).
- **ModifiedMaStop** — moving-average based trailing stop.
("Wilder Volatility System" is intentionally skipped — it overlaps the existing VoltyStop/Psar/SarExt.)
Each takes Candle input; the five band/structure stops emit a {value, direction} struct, TimeBasedStop a scalar. Wired across core, Python/Node/WASM bindings, fuzz target and tests. Verified locally: 3560 core lib + 398 doc tests, clippy clean, 515 node tests, 852 pytest, counter 440.
Version bump for the **v0.6.0** release (ships the B5 Volatility & Bands batch, #189 — 423 -> 429 indicators).
Bumps version strings across Cargo workspace, pyproject, node package.json + 6 platform packages, both package-lock.json files, and Cargo.lock; CHANGELOG `[Unreleased]` -> `[0.6.0]`. No code changes.
Versioning note: patch never reaches two digits — `0.5.9` rolls to the next minor `0.6.0` (not 0.5.10).
Adds six **Volatility & Bands** indicators (Part B5 of the expansion roadmap), 423 → 429.
| Indicator | Input → Output | Summary |
|-----------|----------------|---------|
| `EwmaVolatility` | `f64` → `f64` | RiskMetrics exponentially-weighted volatility (λ decay) |
| `Garch11` | `f64` → `f64` | GARCH(1,1) conditional volatility with a long-run-variance anchor |
| `BipowerVariation` | `f64` → `f64` | jump-robust realized bipower variation (π/2 · Σ\|rₜ\|\|rₜ₋₁\|) |
| `VolatilityRatio` | `Candle` → `f64` | Schwager's true range over the EMA of prior true ranges (>2 = wide-ranging day) |
| `VolatilityCone` | `Candle` → `VolatilityConeOutput` | current realized volatility within its min/median/max envelope + percentile |
| `VolatilityOfVolatility` | `f64` → `f64` | sample stddev of a rolling realized-volatility series |
### Notes
- Two B5 roadmap items were dropped as duplicates/by-construction: `RealizedVolatility` already ships (v0.5.4); `Downside Semi-Deviation` is internal to Sortino. `Bipower Variation` confirmed distinct from `JumpIndicator` (a ±1 flag, not a variance measure).
- `VolatilityRatio` implements the widely-charted EMA-of-true-range convention (denominator excludes the current bar so the 2.0 threshold means "twice typical"), distinct from the existing pairwise `variance_ratio`.
- `Garch11` mean-reverts to `ω/(1−β)` on a flat series (does not decay to 0 like EWMA) — pinned by a dedicated test.
### Coverage / verification
- Full core + Python/Node/WASM bindings, fuzz drivers (scalar + candle), registries, CHANGELOG, README + docs counter sync.
- 100% unit-test coverage per indicator (every branch).
- Green locally: `cargo clippy --workspace --all-targets --all-features -D warnings`, core lib (3479) + doc (387), node (504), python (830).
Deep-dive docs for all six are staged for `wickra-docs` and pushed after release (gated).
Patch release: streaming/batch perf (SMA, Bollinger, RSI, EMA, ATR; outputs unchanged), cross-library benchmark harness, honest tiered README. No new indicators, no API changes.
Adds three **Price Oscillators** family indicators (420 → 423).
## Indicators
- **TsfOscillator** — `100·(close − TSF)/close`, the percentage gap of the close to the **one-bar-ahead** time-series forecast. Close-relative companion to `Cfo`, which measures the same gap against the regression value at the *current* bar; the two differ by exactly the slope term `100·b/close`.
- **MacdHistogram** — the standalone `macd − signal` bar of MACD exposed as a plain `f64` series.
- **PpoHistogram** — the Percentage Price Oscillator with its 9-period signal EMA and the resulting scale-free, zero-centered histogram (PPO itself only emits the line).
All three are scalar `f64` indicators wrapping existing, already-tested building blocks (`MacdIndicator`, `Ppo` + `Ema`, `Tsf`).
## Scope notes (VORAB-CHECK)
The B4 roadmap listed six items; three were dropped to avoid duplicates:
- *Forecast Oscillator* already ships as `Cfo`.
- *Derivative Oscillator* already ships (`DerivativeOscillator`, B2).
- *Detrended Synthetic Price* deferred — no citable formula distinct from the existing `Apo`/`Dpo`.
## Touchpoints
Core (`tsf_oscillator.rs`, `macd_histogram.rs`, `ppo_histogram.rs`) with full per-branch unit tests, `mod.rs`/`lib.rs`, python/node/wasm bindings (wasm via typed-arg macro, python/node hand-written for the multi-arg histograms), fuzz drivers, python reference + streaming-vs-batch tests, node factories, README family row + counter, CHANGELOG.
Local verify: `cargo test --workspace` green, `clippy -D warnings` clean, node 498 tests, full python suite green.
Version bump 0.5.6 → 0.5.7 for the **B3 — Trend & Directional** batch (#181):
seven new indicators (`Qstick`, `TtmTrend`, `TrendStrengthIndex`,
`PolarizedFractalEfficiency`, `WavePm`, `GatorOscillator`,
`KasePermissionStochastic`), catalog 413 → 420.
Bumps: workspace `Cargo.toml` + `Cargo.lock`, `bindings/python/pyproject.toml`,
`bindings/node/package.json` + the six `npm/*/package.json` platform manifests,
both `package-lock.json` files, and the `CHANGELOG.md` `[Unreleased]` → `[0.5.7]`
roll with compare URLs.