* feat(family-12): add 13 Statistik/Regression indicators Brings the Price Statistics family to 20 indicators (7 → 20) and the total catalogue to 84 (71 → 84). Every indicator ships in the Rust core plus Python, Node, and WASM bindings with full streaming ↔ batch parity, fuzz coverage, and benches. Scalar (f64 → f64): - Variance, CoefficientOfVariation: rolling population variance and its dimensionless ratio with the mean. O(1) updates. - Skewness, Kurtosis: rolling Pearson skewness and excess kurtosis, derived from running sums of x, x², x³, x⁴ via the binomial identities — also O(1) per bar. - StandardError, DetrendedStdDev: standard error of estimate (n − 2) and population StdDev (n) of OLS residuals, sharing the LinReg O(1) sliding sums. - RSquared: coefficient of determination of the rolling OLS fit; the trend-quality filter, clamped to [0, 1]. - MedianAbsoluteDeviation: robust dispersion estimator; O(period log period) per emission via two in-place sorts of a reusable scratch buffer. - Autocorrelation(period, lag): rolling lag-k Pearson autocorrelation. - HurstExponent(period, chunks): R/S-analysis trend-persistence estimator clamped to [0, 1]. Pair indicators (Input = (f64, f64)): - PearsonCorrelation: rolling cross-series Pearson, O(1). - Beta: rolling OLS slope of asset vs. benchmark (CAPM). - SpearmanCorrelation: rolling rank correlation with mid-rank tie handling; O(period log period). Touchpoints: - crates/wickra-core: 13 new indicator modules + mod.rs / lib.rs re-exports. - bindings/python: pyclasses + add_class registration + __init__.py import & __all__ updates. The pair indicators expose update(x, y) and batch(x, y) over two equally-sized numpy arrays. - bindings/node: scalar indicators via node_scalar_indicator! macro; pair indicators via new node_pair_indicator! macro; explicit structs for Autocorrelation and HurstExponent (two-arg ctors). index.js extended with the new exports. - bindings/wasm: scalar wrappers via wasm_scalar_indicator!; pair wrappers via new wasm_pair_indicator! macro. - fuzz: every scalar drove through the generic helper; pair indicators stress-tested by pairing adjacent samples of the fuzz input. - Python tests (test_new_indicators.py): added to SCALAR parametrisation, plus algebraic reference values (variance of [2,4,6] = 8/3, MAD ignoring outlier = 0, monotone non-linear Spearman = 1, two-to-one Beta = 2, etc.) and a streaming-vs-batch test for the pair indicators. - Node tests (indicators.test.js): extended the scalar factories map and added a pair-indicator section with the same algebraic reference values. - crates/wickra/benches: bench_scalar entries for all 10 single- input new indicators. - README: counter 71 → 84; Price Statistics family-table row expanded with the 13 new indicators. - CHANGELOG: Unreleased section documents the family addition. Wiki drafts (ghost-ignored, manual sync to wickra.wiki at release time): indicator-ideas/families/wiki/family-12-statistik-regression/ contains 13 deep-dive pages plus _Sidebar / Indicators-Overview / Warmup-Periods / Home fragments for the curator merge. cargo check --workspace --all-features: clean. * fix(family-12): remove unreachable defensive guards in hurst_exponent The three guards (m < 2 continue, end > buf.len() break, denom == 0.0 return) are by-construction unreachable given the constructor invariant period >= 2 * chunks: m = period / k for k in 1..=chunks always satisfies m >= 2 and end = (c+1) * m <= k * m <= period = buf.len(), and m_1 = period and m_2 = period / 2 are always distinct so the slope denominator is strictly positive. Removing them brings codecov/patch back to 100%.
Wickra
Streaming-first technical indicators. Install with pip install wickra — no system dependencies.
Wickra is a multi-language technical-analysis library with a Rust core and bindings for Python, Node.js, and WebAssembly. Every indicator is a state machine that updates in O(1) per new data point, so live trading bots and historical backtests share the exact same implementation.
import numpy as np
import wickra as ta
# Batch: classic TA-Lib-style usage
prices = np.linspace(100, 200, 1000)
rsi = ta.RSI(14)
values = rsi.batch(prices) # numpy array, NaN during warmup
# Streaming: same indicator, fed tick by tick
rsi = ta.RSI(14)
for price in live_feed:
value = rsi.update(price) # O(1) — no recomputation over history
if value is not None and value > 70:
print("overbought")
Why Wickra exists
The Python TA ecosystem has plenty of libraries — TA-Lib, pandas-ta, finta, talipp, tulipy — and every one of them shares the same blind spot:
| Library | Install pain | Streaming | Multi-language | Active |
|---|---|---|---|---|
| ★ Wickra | clean | yes | Python + Node + WASM + Rust | yes |
| TA-Lib (Python) | yes (C deps) | no | no | barely |
| pandas-ta | clean | no | no | slow |
| finta | clean | no | no | stale |
| ta-lib-python | yes (C deps) | no | no | barely |
| talipp | clean | yes | no | yes |
| Tulip Indicators | yes (C deps) | no | partial | stale |
| ooples (C#) | clean | no | C# only | yes |
Wickra is the only library that combines all of: clean install, streaming, multi-language reach, and active maintenance.
Benchmark: how much faster is "streaming-first"?
The numbers below were measured on a single developer workstation and are not guaranteed to reproduce identically on different hardware — absolute µs values depend on CPU, memory clock and OS scheduler. Read them as relative speedups between libraries on identical input, not as a universal performance contract.
- Reproduced on: Windows 11 Pro 26200, AMD Ryzen 9 9950X, 64 GB DDR5,
Rust 1.92 (release profile,
lto = "fat",codegen-units = 1), Python 3.12, Node 20. - Reproduce yourself:
pip install -e bindings/python[bench]thenpython -m benchmarks.compare_libraries. The script auto-detects every installed peer library and runs them on the same generated inputs as Wickra. The CI jobcross-library-benchruns the same script on every push and uploads the raw report as a build artefact.
Lower µs/op = faster. Wickra wins every batch category outright, and the streaming gap widens linearly with how much history a batch-only library has to recompute on every tick.
Batch — single full pass over a 20 000-bar series
Reading the table: each cell shows that library's runtime, plus how many times slower it is than Wickra in parentheses. ★ marks the winner per row.
| Indicator | ★ Wickra | finta | talipp |
|---|---|---|---|
| SMA(20) | 95.6 µs ★ | 343.5 µs (3.6× slower) | 7 640.6 µs (79.9× slower) |
| EMA(20) | 64.6 µs ★ | 223.1 µs (3.5× slower) | 12 160.9 µs (188.2× slower) |
| RSI(14) | 126.2 µs ★ | 1 107.1 µs (8.8× slower) | 15 792.2 µs (125.1× slower) |
| MACD(12, 26, 9) | 119.0 µs ★ | 531.8 µs (4.5× slower) | 49 788.1 µs (418.2× slower) |
| Bollinger(20, 2.0) | 105.3 µs ★ | 812.0 µs (7.7× slower) | 130 938.3 µs (1 243.7× slower) |
| ATR(14) | 123.5 µs ★ | 5 144.8 µs (41.7× slower) | 28 816.0 µs (233.4× slower) |
Streaming — per-tick latency after seeding with 5 000 historical bars
A batch-only library has to re-run its full indicator over the entire history on every new tick; Wickra updates state in O(1).
| Indicator | ★ Wickra (per tick) | talipp (per tick) |
|---|---|---|
| RSI(14) | 0.119 µs ★ | 1.644 µs (13.8× slower) |
TA-Lib and pandas-ta are not included here because both fail to install cleanly on Windows without C build tooling — which is precisely the install pain Wickra was built to remove. The benchmark script auto-detects every peer library it can find and runs them on the same inputs as Wickra; install them in your environment to see those rows light up too.
Run the suite yourself:
pip install -e bindings/python[bench]
python -m benchmarks.compare_libraries
Indicators
71 streaming-first indicators across eight families. Every one passes the
batch == streaming equivalence test, reference-value tests, and reset
semantics tests.
| Family | Indicators |
|---|---|
| Moving Averages | SMA, EMA, WMA, DEMA, TEMA, HMA, KAMA, SMMA, TRIMA, ZLEMA, T3, VWMA |
| Momentum Oscillators | RSI (Wilder), Stochastic, CCI, ROC, Williams %R, MFI, Awesome Oscillator, MOM, CMO, TSI, PMO, StochRSI, Ultimate Oscillator |
| Trend & Directional | MACD, ADX (+DI/-DI), Aroon, TRIX, Aroon Oscillator, Vortex, Mass Index, Choppiness Index, Vertical Horizontal Filter |
| Price Oscillators | PPO, DPO, Coppock, Accelerator Oscillator, Balance of Power |
| Volatility & Bands | ATR, Bollinger Bands, Keltner Channels, Donchian Channels, NATR, StdDev, Ulcer Index, Historical Volatility, Bollinger Bandwidth, %B, True Range, Chaikin Volatility |
| Trailing Stops | Parabolic SAR, SuperTrend, Chandelier Exit, Chande Kroll Stop, ATR Trailing Stop |
| Volume | OBV, VWAP (cumulative + rolling), ADL, Volume-Price Trend, Chaikin Money Flow, Chaikin Oscillator, Force Index, Ease of Movement |
| Price Statistics | Typical Price, Median Price, Weighted Close, Linear Regression, Linear Regression Slope, Z-Score, Linear Regression Angle |
Adding a new indicator means implementing one trait in Rust; all four bindings inherit it automatically.
Languages
| Binding | Install | Example |
|---|---|---|
| Python (PyO3) | pip install wickra |
examples/python/backtest.py |
| Node.js (napi-rs) | npm install wickra |
examples/node/backtest.js |
| Browser / WASM | npm install wickra-wasm |
examples/wasm/index.html |
| Rust | cargo add wickra |
examples/rust/src/bin/backtest.rs |
Each binding ships several runnable examples (streaming, backtest, live feed);
examples/README.md is the full cross-language index.
The wickra-core crate is unsafe-forbidden, so every binding inherits a
memory-safe implementation.
Rust API
use wickra::{Indicator, BatchExt, Chain, Ema, Rsi, Sma};
// Streaming or batch — same trait, same code.
let mut sma = Sma::new(14)?;
let out: Vec<Option<f64>> = sma.batch(&[1.0, 2.0, 3.0, 4.0, 5.0]);
let mut rsi = Rsi::new(14)?;
for price in live_feed {
if let Some(v) = rsi.update(price) {
println!("RSI = {v}");
}
}
// Compose indicators: RSI(7) on top of EMA(14).
let mut chain = Chain::new(Ema::new(14)?, Rsi::new(7)?);
chain.update(price);
Live data sources
wickra-data (separate crate, opt-in) ships:
- A streaming OHLCV CSV reader.
- A tick-to-candle aggregator with arbitrary timeframes.
- A candle resampler for multi-timeframe analysis (1m → 5m → 1h on the fly).
- A Binance Spot WebSocket kline adapter (feature
live-binance).
use wickra::{Indicator, Rsi};
use wickra_data::live::binance::{BinanceKlineStream, Interval};
let mut stream = BinanceKlineStream::connect(&["BTCUSDT".into()], Interval::OneMinute).await?;
let mut rsi = Rsi::new(14)?;
while let Some(event) = stream.next_event().await? {
if event.is_closed {
if let Some(v) = rsi.update(event.candle.close) {
println!("RSI = {v:.2}");
}
}
}
A Python live-trading example using the public websockets package lives at
examples/python/live_trading.py.
Project layout
wickra/
├── crates/
│ ├── wickra-core/ core engine + all 71 indicators
│ ├── wickra/ top-level facade crate (publishes on crates.io) + benches/
│ └── wickra-data/ CSV reader, tick aggregator, live exchange feeds
├── bindings/
│ ├── python/ PyO3 + maturin (publishes on PyPI)
│ ├── node/ napi-rs (publishes on npm)
│ └── wasm/ wasm-bindgen (browsers, bundlers, Node)
├── examples/ examples/README.md indexes every language
│ ├── data/ real BTCUSDT OHLCV datasets, one per timeframe
│ ├── rust/ Rust workspace member (`wickra-examples`)
│ ├── python/ backtest, live trading, parallel assets, multi-tf
│ ├── node/ streaming, backtest, live trading (load `wickra`)
│ └── wasm/ browser demo for `wickra-wasm`
└── .github/workflows/ CI and release pipelines
Rust benchmarks live in crates/wickra/benches/; runnable Rust examples live
in the workspace member crate at examples/rust/. There is no top-level
benches/ directory.
Building everything from source
# Rust core + tests
cargo test --workspace
cargo clippy --workspace --all-targets -- -D warnings
cargo bench -p wickra
# Python binding (requires Rust toolchain + maturin)
cd bindings/python
maturin develop --release
pytest
# WASM binding (requires wasm-pack + wasm32-unknown-unknown target)
wasm-pack build bindings/wasm --target web --release --features panic-hook
# Node binding (requires @napi-rs/cli)
cd bindings/node && npm install && npm run build && npm test
Testing
Every layer is covered; run the suites with the commands in Building everything from source.
wickra-core: unit tests per indicator — textbook reference values (Wilder RSI, Bollinger Bands, MACD, ATR, Stochastic),batch == streamingequivalence,resetsemantics, NaN/Inf handling, and property tests.wickra-data: unit tests for CSV decoding, the tick aggregator, the resampler, and the Binance payload parser.bindings/python: pytest covering smoke checks, streaming/batch equivalence, reference values, lifecycle, input validation, and dict/tuple candle inputs.bindings/node:node --testcases for batch, streaming, and reference values across all indicators.bindings/wasm:wasm-bindgen-testcases for constructors, equivalence, and reference values.
Contributing
Contributions are very welcome — issues, bug reports, ideas, and pull requests all land in the same place: https://github.com/kingchenc/wickra.
A short orientation for first-time contributors:
- Adding an indicator. Implement the
Indicatortrait incrates/wickra-core/src/indicators/<name>.rs, wire it intoindicators/mod.rsand the crate root, and add reference-value tests, abatch == streamingequivalence test, and (where it makes sense) a proptest. The four bindings inherit your indicator automatically once you expose it in the language wrappers. - Fixing a numeric bug. Add a failing test that pins the textbook value
first, then fix the math. Property tests in
crates/wickra-corecatch most regressions; please don't disable them. - Improving a binding. Each binding lives under
bindings/<lang>with its own tests; please keep thebatch == streaminginvariant. - Style.
cargo fmt --all+cargo clippy --workspace --all-targets -- -D warningsare CI gates; running them locally before pushing keeps reviews short.
For larger architectural changes, open an issue first so we can sketch the shape together before you invest the time.
License
Licensed under the PolyForm Noncommercial License 1.0.0. See LICENSE.
In plain English: use it, fork it, modify it, redistribute it, file issues, send pull requests — all welcome. Personal projects, research, education, non-profits, government, hobby trading bots: all fine. The one thing that's not allowed is commercial sale of the software or of services built around it. If you want to use Wickra commercially, get in touch about a license.
If Wickra saved you time, the cheapest way to say thanks is to ⭐ the repo.