F2: add ZLEMA, T3 and VWMA advanced moving averages

Completes the F2 family (Advanced MAs) end to end:

- Rust core: zlema.rs (Zero-Lag EMA over the de-lagged series
  2·price − price[lag]), t3.rs (Tillson's six-EMA cascade with the
  volume-factor polynomial), vwma.rs (volume-weighted rolling mean with
  a zero-volume fallback to the unweighted mean). Each with a full
  Indicator impl, runnable doctest and reference-value / warmup /
  reset / batch==streaming / non-finite tests.
- Python: PyZlema / PyT3 / PyVwma PyO3 classes + module registration
  + .pyi stubs (T3 defaults v=0.7).
- Node: ZlemaNode via the scalar macro, explicit T3Node and VwmaNode
  classes; index.d.ts and index.js updated.
- WASM: WasmZlema / WasmT3 via the scalar macro, explicit WasmVwma.
- Wiki: Indicator-Zlema.md, Indicator-T3.md, Indicator-Vwma.md plus
  rows in Indicators-Overview.md and entries in Home.md.

cargo fmt + clippy (core/wickra/data/wasm/node) clean; 232 core tests,
25 data tests and 33 doctests green.
This commit is contained in:
kingchenc
2026-05-22 17:45:02 +02:00
parent ed7324115c
commit 780a176072
15 changed files with 1573 additions and 3 deletions
+261
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//! Tillson T3 Moving Average.
use crate::error::{Error, Result};
use crate::traits::Indicator;
use super::Ema;
/// Tillson's T3 — a six-fold cascaded EMA recombined with a *volume factor* `v`.
///
/// T3 is the generalised DEMA applied three times. Tim Tillson's expansion of
/// that triple application over six chained EMAs (`e1 … e6`, each of the same
/// `period`) gives the closed form used here:
///
/// ```text
/// c1 =
/// c2 = 3v² + 3v³
/// c3 = 6v² 3v 3v³
/// c4 = 1 + 3v + v³ + 3v²
/// T3 = c1·e6 + c2·e5 + c3·e4 + c4·e3
/// ```
///
/// The volume factor `v ∈ [0, 1]` controls the lag/smoothness trade-off:
/// `v = 0` collapses T3 to the plain triple-cascaded EMA `e3`, while the
/// conventional `v = 0.7` adds a hump that sharpens the response to turns.
/// The coefficients always sum to `1`, so a constant series maps to itself.
///
/// The first output lands after `6·period 5` inputs — the index at which the
/// sixth cascaded EMA seeds.
///
/// # Example
///
/// ```
/// use wickra_core::{Indicator, T3};
///
/// let mut indicator = T3::new(5, 0.7).unwrap();
/// let mut last = None;
/// for i in 0..120 {
/// last = indicator.update(100.0 + f64::from(i));
/// }
/// assert!(last.is_some());
/// ```
#[derive(Debug, Clone)]
pub struct T3 {
period: usize,
v: f64,
c1: f64,
c2: f64,
c3: f64,
c4: f64,
e1: Ema,
e2: Ema,
e3: Ema,
e4: Ema,
e5: Ema,
e6: Ema,
current: Option<f64>,
}
impl T3 {
/// Construct a new T3 with the given `period` and volume factor `v`.
///
/// # Errors
///
/// Returns [`Error::PeriodZero`] if `period == 0`, or
/// [`Error::InvalidPeriod`] if `v` is non-finite or outside `[0.0, 1.0]`.
pub fn new(period: usize, v: f64) -> Result<Self> {
if period == 0 {
return Err(Error::PeriodZero);
}
if !v.is_finite() || !(0.0..=1.0).contains(&v) {
return Err(Error::InvalidPeriod {
message: "T3 volume factor must be a finite value in [0.0, 1.0]",
});
}
let v2 = v * v;
let v3 = v2 * v;
Ok(Self {
period,
v,
c1: -v3,
c2: 3.0 * v2 + 3.0 * v3,
c3: -6.0 * v2 - 3.0 * v - 3.0 * v3,
c4: 1.0 + 3.0 * v + v3 + 3.0 * v2,
e1: Ema::new(period)?,
e2: Ema::new(period)?,
e3: Ema::new(period)?,
e4: Ema::new(period)?,
e5: Ema::new(period)?,
e6: Ema::new(period)?,
current: None,
})
}
/// Configured period.
pub const fn period(&self) -> usize {
self.period
}
/// Configured volume factor `v`.
pub const fn volume_factor(&self) -> f64 {
self.v
}
/// Current value if available.
pub const fn value(&self) -> Option<f64> {
self.current
}
}
impl Indicator for T3 {
type Input = f64;
type Output = f64;
fn update(&mut self, input: f64) -> Option<f64> {
if !input.is_finite() {
// Non-finite input is ignored; the cascade is not advanced.
return self.current;
}
let e1 = self.e1.update(input)?;
let e2 = self.e2.update(e1)?;
let e3 = self.e3.update(e2)?;
let e4 = self.e4.update(e3)?;
let e5 = self.e5.update(e4)?;
let e6 = self.e6.update(e5)?;
let out = self.c1 * e6 + self.c2 * e5 + self.c3 * e4 + self.c4 * e3;
self.current = Some(out);
Some(out)
}
fn reset(&mut self) {
self.e1.reset();
self.e2.reset();
self.e3.reset();
self.e4.reset();
self.e5.reset();
self.e6.reset();
self.current = None;
}
fn warmup_period(&self) -> usize {
6 * self.period - 5
}
fn is_ready(&self) -> bool {
self.current.is_some()
}
fn name(&self) -> &'static str {
"T3"
}
}
#[cfg(test)]
mod tests {
use super::*;
use crate::traits::BatchExt;
use approx::assert_relative_eq;
#[test]
fn new_rejects_zero_period() {
assert!(matches!(T3::new(0, 0.7), Err(Error::PeriodZero)));
}
#[test]
fn new_rejects_out_of_range_volume_factor() {
assert!(matches!(T3::new(5, -0.1), Err(Error::InvalidPeriod { .. })));
assert!(matches!(T3::new(5, 1.5), Err(Error::InvalidPeriod { .. })));
assert!(matches!(
T3::new(5, f64::NAN),
Err(Error::InvalidPeriod { .. })
));
assert!(T3::new(5, 0.0).is_ok());
assert!(T3::new(5, 1.0).is_ok());
}
#[test]
fn coefficients_sum_to_one() {
// c1 + c2 + c3 + c4 == 1 for any v, so a constant series is preserved.
for &v in &[0.0, 0.3, 0.7, 1.0] {
let t3 = T3::new(5, v).unwrap();
assert_relative_eq!(t3.c1 + t3.c2 + t3.c3 + t3.c4, 1.0, epsilon = 1e-12);
}
}
#[test]
fn first_emission_at_warmup_period() {
let mut t3 = T3::new(4, 0.7).unwrap();
assert_eq!(t3.warmup_period(), 6 * 4 - 5);
let out = t3.batch(&(1..=60).map(f64::from).collect::<Vec<_>>());
for v in out.iter().take(t3.warmup_period() - 1) {
assert!(v.is_none());
}
assert!(out[t3.warmup_period() - 1].is_some());
}
#[test]
fn constant_series_yields_the_constant() {
let mut t3 = T3::new(6, 0.7).unwrap();
let out = t3.batch(&[50.0; 80]);
let last = out.iter().rev().flatten().next().unwrap();
assert_relative_eq!(*last, 50.0, epsilon = 1e-9);
}
#[test]
fn zero_volume_factor_collapses_to_triple_cascaded_ema() {
// With v = 0 the coefficients are c1=c2=c3=0, c4=1, so T3 == e3,
// the third stage of the EMA cascade.
let prices: Vec<f64> = (1..=80)
.map(|i| 100.0 + (f64::from(i) * 0.2).sin() * 9.0)
.collect();
let mut t3 = T3::new(5, 0.0).unwrap();
let got = t3.batch(&prices);
let mut e1 = Ema::new(5).unwrap();
let mut e2 = Ema::new(5).unwrap();
let mut e3 = Ema::new(5).unwrap();
let want: Vec<Option<f64>> = prices
.iter()
.map(|p| {
e1.update(*p)
.and_then(|a| e2.update(a))
.and_then(|b| e3.update(b))
})
.collect();
for i in (t3.warmup_period() - 1)..prices.len() {
assert_relative_eq!(got[i].unwrap(), want[i].unwrap(), epsilon = 1e-9);
}
}
#[test]
fn ignores_non_finite_input() {
let mut t3 = T3::new(4, 0.7).unwrap();
let out = t3.batch(&(1..=60).map(f64::from).collect::<Vec<_>>());
let last = *out.last().unwrap();
assert!(last.is_some());
assert_eq!(t3.update(f64::NAN), last);
assert_eq!(t3.update(f64::INFINITY), last);
}
#[test]
fn reset_clears_state() {
let mut t3 = T3::new(4, 0.7).unwrap();
t3.batch(&(1..=60).map(f64::from).collect::<Vec<_>>());
assert!(t3.is_ready());
t3.reset();
assert!(!t3.is_ready());
assert_eq!(t3.update(1.0), None);
}
#[test]
fn batch_equals_streaming() {
let prices: Vec<f64> = (1..=120)
.map(|i| 100.0 + (f64::from(i) * 0.25).sin() * 7.0)
.collect();
let batch = T3::new(7, 0.7).unwrap().batch(&prices);
let mut b = T3::new(7, 0.7).unwrap();
let streamed: Vec<_> = prices.iter().map(|p| b.update(*p)).collect();
assert_eq!(batch, streamed);
}
}