Previous workflow train-4qwtc hit memory-pressure thrash (~56Gi
cgroup.current sitting at the 56Gi pod limit, kernel reclaim
hammering page cache) right after OFI completed on the 9-quarter
17.8M-bar dataset. Two refactors reduce peak by ~12GB:
(1) walk_forward.rs: new `normalize_batch_in_place(&mut features)`
that rewrites the slice in place. The previous `normalize_batch`
`.collect()`s a new Vec — at this dataset size that's a
transient ~6GB peak while both pre- and post-normalised arrays
are alive.
(2) precompute_features.rs:
- call `normalize_batch_in_place` instead of the rebinding form.
- explicit `drop(feature_vectors)` after copying the slice into
`features` — `feature_vectors` would otherwise stay alive
until end-of-main shadowing the ~6GB allocation through
every downstream step.
Combined with the prior `t.into_iter()` refactor (a27cb40a9), the
peak transient drops from ~56GB to ~44GB — well under the 56Gi pod
limit on the existing ci-compile-cpu pool (POP2-HC-32C-64G).
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
1184 lines
44 KiB
Rust
1184 lines
44 KiB
Rust
//! Walk-forward evaluation framework for time-series ML models.
|
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//!
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//! Implements expanding-window walk-forward cross-validation with configurable
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//! train/val/test splits and feature normalization. This prevents lookahead bias
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//! by ensuring models are always evaluated on unseen future data.
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//!
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//! # Walk-Forward Split Diagram
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//!
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//! ```text
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//! Fold 0: |------- Train (12mo) -------|-- Val (3mo) --|-- Test (3mo) --|
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//! Fold 1: |---------- Train (15mo) ----------|-- Val --|-- Test --|
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//! Fold 2: |------------- Train (18mo) --------------|-- Val --|-- Test --|
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//! ```
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//!
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//! # Usage
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//!
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//! ```rust,no_run
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//! use ml::walk_forward::{WalkForwardConfig, generate_walk_forward_windows, NormStats};
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//!
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//! let config = WalkForwardConfig::default();
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//! let windows = generate_walk_forward_windows(&bars, &config);
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//!
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//! for window in &windows {
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//! let features = extract_ml_features(&window.train)?;
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//! let stats = NormStats::from_features(&features);
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//! let normalized = stats.normalize_batch(&features);
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//! // Train model on normalized features...
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//! }
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//! ```
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use crate::types::OHLCVBar;
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use chrono::{Months, NaiveDate};
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/// Configuration for walk-forward evaluation window generation.
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#[derive(Debug, Clone)]
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pub struct WalkForwardConfig {
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/// Number of months in the initial training window (default: 12).
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pub initial_train_months: u32,
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/// Number of months in the validation window (default: 3).
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pub val_months: u32,
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/// Number of months in the test window (default: 3).
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pub test_months: u32,
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/// Number of months to step forward between folds (default: 3).
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pub step_months: u32,
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}
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impl Default for WalkForwardConfig {
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fn default() -> Self {
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Self {
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initial_train_months: 12,
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val_months: 3,
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test_months: 3,
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step_months: 3,
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}
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}
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}
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/// A single walk-forward evaluation window containing train/val/test splits.
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#[derive(Debug, Clone)]
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pub struct WalkForwardWindow {
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/// Zero-based fold index.
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pub fold: usize,
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/// Training bars (expanding window).
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pub train: Vec<OHLCVBar>,
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/// Validation bars.
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pub val: Vec<OHLCVBar>,
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/// Test bars.
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pub test: Vec<OHLCVBar>,
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/// End date of the training period (exclusive boundary).
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pub train_end: NaiveDate,
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/// End date of the validation period (exclusive boundary).
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pub val_end: NaiveDate,
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/// End date of the test period (exclusive boundary).
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pub test_end: NaiveDate,
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/// Difficulty score for curriculum learning (mean ADX over training bars).
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/// Low ADX (<20) = easy trending market, high ADX fluctuation = harder.
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/// Computed via [`compute_difficulty`] after window generation.
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pub difficulty_score: f64,
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}
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/// Curriculum phase for difficulty-based walk-forward window filtering.
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///
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/// Controls which windows are included in training based on their ADX-derived
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/// difficulty score. Progression: Easy -> Mixed -> Full mirrors the standard
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/// curriculum learning approach of starting with simple examples.
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#[derive(Debug, Clone, Copy, PartialEq, Eq)]
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pub enum DifficultyPhase {
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/// Only windows with mean ADX > 30 (clear trending markets, easier to learn).
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Easy,
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/// All windows included, but trending windows (ADX > 30) are weighted 2x
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/// via duplication in the returned list.
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Mixed,
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/// All windows with equal weight (full training, no filtering).
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Full,
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}
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impl DifficultyPhase {
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/// Create a `DifficultyPhase` from a numeric index.
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///
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/// * `0` => `Easy`
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/// * `1` => `Mixed`
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/// * `2` (or any other value) => `Full`
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pub fn from_index(idx: usize) -> Self {
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match idx {
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0 => Self::Easy,
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1 => Self::Mixed,
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_ => Self::Full,
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}
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}
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}
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/// ADX threshold used to classify a window as "trending" (easy) for curriculum learning.
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const ADX_TRENDING_THRESHOLD: f64 = 30.0;
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/// Compute a difficulty score for a slice of OHLCV bars based on mean ADX(14).
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///
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/// ADX (Average Directional Index) measures trend strength on a 0-100 scale.
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/// High ADX (>30) indicates a clear trend which is easier for RL agents to exploit.
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/// Low or fluctuating ADX indicates choppy, range-bound markets that are harder.
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///
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/// Returns the mean ADX value over the bar slice. If the slice has fewer than
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/// 15 bars (minimum for ADX(14) calculation), returns 0.0.
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///
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/// # Algorithm
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///
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/// 1. Compute True Range (TR) for each bar
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/// 2. Compute +DM / -DM directional movement
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/// 3. Smooth TR, +DM, -DM with 14-period Wilder EMA
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/// 4. Compute +DI / -DI and DX
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/// 5. Smooth DX with 14-period Wilder EMA to get ADX
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/// 6. Return mean ADX over valid bars
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pub fn compute_difficulty(bars: &[OHLCVBar]) -> f64 {
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let period: usize = 14;
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// Need at least period + 1 bars for one ADX value
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if bars.len() < period.saturating_add(1) {
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return 0.0;
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}
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// Step 1-2: Compute True Range and Directional Movement
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let mut tr_values = Vec::with_capacity(bars.len().saturating_sub(1));
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let mut plus_dm_values = Vec::with_capacity(bars.len().saturating_sub(1));
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let mut minus_dm_values = Vec::with_capacity(bars.len().saturating_sub(1));
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for i in 1..bars.len() {
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let prev = match bars.get(i.wrapping_sub(1)) {
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Some(b) => b,
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None => continue,
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};
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let curr = match bars.get(i) {
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Some(b) => b,
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None => continue,
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};
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// True Range = max(H-L, |H-prev_close|, |L-prev_close|)
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let hl = curr.high - curr.low;
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let hpc = (curr.high - prev.close).abs();
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let lpc = (curr.low - prev.close).abs();
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let tr = hl.max(hpc).max(lpc);
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tr_values.push(tr);
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// +DM = max(H - prev_H, 0) if > max(prev_L - L, 0), else 0
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let up_move = curr.high - prev.high;
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let down_move = prev.low - curr.low;
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let plus_dm = if up_move > down_move && up_move > 0.0 {
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up_move
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} else {
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0.0
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};
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let minus_dm = if down_move > up_move && down_move > 0.0 {
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down_move
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} else {
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0.0
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};
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plus_dm_values.push(plus_dm);
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minus_dm_values.push(minus_dm);
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}
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if tr_values.len() < period {
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return 0.0;
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}
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// Step 3: Wilder smoothing (initial = sum of first `period` values, then EMA)
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let mut smoothed_tr: f64 = tr_values.iter().take(period).sum();
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let mut smoothed_plus_dm: f64 = plus_dm_values.iter().take(period).sum();
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let mut smoothed_minus_dm: f64 = minus_dm_values.iter().take(period).sum();
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let period_f64 = period as f64;
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let mut dx_values = Vec::with_capacity(tr_values.len().saturating_sub(period));
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// First DX from initial smoothed values
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if smoothed_tr.abs() > 1e-12 {
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let plus_di = 100.0 * smoothed_plus_dm / smoothed_tr;
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let minus_di = 100.0 * smoothed_minus_dm / smoothed_tr;
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let di_sum = plus_di + minus_di;
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if di_sum.abs() > 1e-12 {
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let dx = 100.0 * (plus_di - minus_di).abs() / di_sum;
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dx_values.push(dx);
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}
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}
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// Subsequent smoothed values using Wilder's method
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for i in period..tr_values.len() {
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let tr_val = match tr_values.get(i) {
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Some(&v) => v,
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None => continue,
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};
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let pdm_val = match plus_dm_values.get(i) {
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Some(&v) => v,
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None => continue,
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};
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let mdm_val = match minus_dm_values.get(i) {
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Some(&v) => v,
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None => continue,
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};
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smoothed_tr = smoothed_tr - (smoothed_tr / period_f64) + tr_val;
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smoothed_plus_dm = smoothed_plus_dm - (smoothed_plus_dm / period_f64) + pdm_val;
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smoothed_minus_dm = smoothed_minus_dm - (smoothed_minus_dm / period_f64) + mdm_val;
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if smoothed_tr.abs() > 1e-12 {
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let plus_di = 100.0 * smoothed_plus_dm / smoothed_tr;
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let minus_di = 100.0 * smoothed_minus_dm / smoothed_tr;
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let di_sum = plus_di + minus_di;
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if di_sum.abs() > 1e-12 {
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let dx = 100.0 * (plus_di - minus_di).abs() / di_sum;
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dx_values.push(dx);
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}
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}
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}
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if dx_values.len() < period {
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return 0.0;
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}
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// Step 5: Smooth DX with Wilder EMA to get ADX
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let mut adx: f64 = dx_values.iter().take(period).sum::<f64>() / period_f64;
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let mut adx_values = vec![adx];
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for i in period..dx_values.len() {
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let dx_val = match dx_values.get(i) {
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Some(&v) => v,
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None => continue,
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};
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adx = (adx * (period_f64 - 1.0) + dx_val) / period_f64;
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adx_values.push(adx);
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}
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// Step 6: Return mean ADX
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if adx_values.is_empty() {
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return 0.0;
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}
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let sum: f64 = adx_values.iter().sum();
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sum / adx_values.len() as f64
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}
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/// Filter walk-forward windows by curriculum difficulty phase.
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///
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/// This function applies difficulty-based filtering to a set of walk-forward
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/// windows, enabling curriculum learning by controlling which market conditions
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/// the agent trains on.
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///
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/// # Phases
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///
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/// * [`DifficultyPhase::Easy`] — Only windows with ADX > 30 (trending, easier markets).
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/// * [`DifficultyPhase::Mixed`] — All windows, but trending windows are duplicated for 2x weight.
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/// * [`DifficultyPhase::Full`] — All windows with equal weight (no filtering).
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///
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/// # Arguments
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///
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/// * `windows` — Walk-forward windows with pre-computed `difficulty_score`.
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/// * `phase` — The curriculum phase to apply.
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pub fn filter_by_difficulty(
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windows: &[WalkForwardWindow],
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phase: DifficultyPhase,
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) -> Vec<WalkForwardWindow> {
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match phase {
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DifficultyPhase::Easy => {
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// Only trending windows (ADX > 30)
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windows
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.iter()
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.filter(|w| w.difficulty_score > ADX_TRENDING_THRESHOLD)
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.cloned()
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.collect()
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}
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DifficultyPhase::Mixed => {
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// All windows, trending ones duplicated for 2x weight
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let mut result = Vec::with_capacity(windows.len().saturating_mul(2));
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for w in windows {
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result.push(w.clone());
|
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if w.difficulty_score > ADX_TRENDING_THRESHOLD {
|
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result.push(w.clone());
|
||
}
|
||
}
|
||
result
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||
}
|
||
DifficultyPhase::Full => {
|
||
// All windows, equal weight
|
||
windows.to_vec()
|
||
}
|
||
}
|
||
}
|
||
|
||
/// Minimum number of bars required in each split to form a valid window.
|
||
const MIN_BARS_PER_SPLIT: usize = 50;
|
||
|
||
/// Generate expanding walk-forward windows from sorted OHLCV bars.
|
||
///
|
||
/// Each successive fold extends the training window while keeping
|
||
/// val/test windows the same size, stepping forward by `step_months`.
|
||
///
|
||
/// Returns an empty `Vec` if the data is insufficient for even one fold.
|
||
///
|
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/// # Arguments
|
||
///
|
||
/// * `bars` - Chronologically sorted OHLCV bars
|
||
/// * `config` - Walk-forward configuration
|
||
pub fn generate_walk_forward_windows(
|
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bars: &[OHLCVBar],
|
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config: &WalkForwardConfig,
|
||
) -> Vec<WalkForwardWindow> {
|
||
if bars.is_empty() {
|
||
return Vec::new();
|
||
}
|
||
|
||
// Determine date range from the data
|
||
let first_bar = match bars.first() {
|
||
Some(b) => b,
|
||
None => return Vec::new(),
|
||
};
|
||
let last_bar = match bars.last() {
|
||
Some(b) => b,
|
||
None => return Vec::new(),
|
||
};
|
||
|
||
let data_start = first_bar.timestamp.date_naive();
|
||
let data_end = last_bar.timestamp.date_naive();
|
||
|
||
let mut windows = Vec::new();
|
||
let mut fold = 0_usize;
|
||
|
||
loop {
|
||
// Train end: initial_train_months + fold * step_months from data_start
|
||
let total_train_months = config
|
||
.initial_train_months
|
||
.saturating_add(fold as u32 * config.step_months);
|
||
let train_end = match data_start.checked_add_months(Months::new(total_train_months)) {
|
||
Some(d) => d,
|
||
None => break,
|
||
};
|
||
|
||
// Val end: train_end + val_months
|
||
let val_end = match train_end.checked_add_months(Months::new(config.val_months)) {
|
||
Some(d) => d,
|
||
None => break,
|
||
};
|
||
|
||
// Test end: val_end + test_months
|
||
let test_end = match val_end.checked_add_months(Months::new(config.test_months)) {
|
||
Some(d) => d,
|
||
None => break,
|
||
};
|
||
|
||
// If test_end exceeds data range, we cannot form this fold.
|
||
// Use `>` with +1 day margin: bars with `date_naive() < test_end` captures
|
||
// all bars ON the last calendar day of the test window. Without the margin,
|
||
// quarterly data ending on e.g. Jun-30 fails when test_end = Jul-01.
|
||
if test_end > data_end + chrono::Duration::days(1) {
|
||
break;
|
||
}
|
||
|
||
// Partition bars into train/val/test using date boundaries
|
||
let train_bars: Vec<OHLCVBar> = bars
|
||
.iter()
|
||
.filter(|b| b.timestamp.date_naive() < train_end)
|
||
.copied()
|
||
.collect();
|
||
|
||
// Audit follow-up: insert PURGE_BARS gap between train and val.
|
||
// Date-based partition has no per-bar index, so drop the first
|
||
// `PURGE_BARS` bars whose date is in `[train_end, val_end)` —
|
||
// matches the bar-count purge applied by the index-based
|
||
// variants below. Test/val window endpoints stay date-anchored
|
||
// so total fold coverage is preserved (val_len shrinks by
|
||
// exactly `PURGE_BARS`).
|
||
let raw_val_bars: Vec<OHLCVBar> = bars
|
||
.iter()
|
||
.filter(|b| {
|
||
let d = b.timestamp.date_naive();
|
||
d >= train_end && d < val_end
|
||
})
|
||
.copied()
|
||
.collect();
|
||
let val_bars: Vec<OHLCVBar> = if raw_val_bars.len() > PURGE_BARS {
|
||
raw_val_bars.into_iter().skip(PURGE_BARS).collect()
|
||
} else {
|
||
// Degenerate fold — purge would consume the entire window;
|
||
// the `val_bars.len() < MIN_BARS_PER_SPLIT` gate below will
|
||
// skip this fold, so keep raw_val_bars empty-passthrough.
|
||
raw_val_bars
|
||
};
|
||
|
||
let test_bars: Vec<OHLCVBar> = bars
|
||
.iter()
|
||
.filter(|b| {
|
||
let d = b.timestamp.date_naive();
|
||
d >= val_end && d < test_end
|
||
})
|
||
.copied()
|
||
.collect();
|
||
|
||
// Skip folds where any split has fewer than MIN_BARS_PER_SPLIT bars
|
||
if train_bars.len() < MIN_BARS_PER_SPLIT
|
||
|| val_bars.len() < MIN_BARS_PER_SPLIT
|
||
|| test_bars.len() < MIN_BARS_PER_SPLIT
|
||
{
|
||
// If training set is too small, later folds might still work
|
||
// But if val/test are too small at the end, no point continuing
|
||
if val_bars.len() < MIN_BARS_PER_SPLIT || test_bars.len() < MIN_BARS_PER_SPLIT {
|
||
// Check if we have already generated at least one fold or if
|
||
// the data simply does not support this fold size
|
||
if fold > 0 {
|
||
break;
|
||
}
|
||
// For fold 0 with insufficient data, skip but try next fold
|
||
fold = fold.saturating_add(1);
|
||
continue;
|
||
}
|
||
fold = fold.saturating_add(1);
|
||
continue;
|
||
}
|
||
|
||
let difficulty_score = compute_difficulty(&train_bars);
|
||
windows.push(WalkForwardWindow {
|
||
fold,
|
||
train: train_bars,
|
||
val: val_bars,
|
||
test: test_bars,
|
||
train_end,
|
||
val_end,
|
||
test_end,
|
||
difficulty_score,
|
||
});
|
||
|
||
fold = fold.saturating_add(1);
|
||
}
|
||
|
||
windows
|
||
}
|
||
|
||
/// Walk-forward fold as index ranges into pre-loaded arrays.
|
||
/// Zero data copying — just start/end indices into bars/features arrays.
|
||
#[derive(Debug, Clone)]
|
||
pub struct FoldRange {
|
||
pub fold: usize,
|
||
pub train_start: usize,
|
||
pub train_end: usize,
|
||
pub val_start: usize,
|
||
pub val_end: usize,
|
||
pub difficulty_score: f64,
|
||
}
|
||
|
||
/// Generate walk-forward folds as index ranges (zero-copy).
|
||
///
|
||
/// Same date-boundary logic as `generate_walk_forward_windows` but returns
|
||
/// `(start, end)` indices instead of cloning bars. Uses `partition_point`
|
||
/// for O(log n) index lookup.
|
||
pub fn generate_walk_forward_indices(
|
||
bars: &[OHLCVBar],
|
||
config: &WalkForwardConfig,
|
||
) -> Vec<FoldRange> {
|
||
if bars.is_empty() {
|
||
return Vec::new();
|
||
}
|
||
|
||
let data_start = bars[0].timestamp.date_naive();
|
||
let data_end = bars[bars.len() - 1].timestamp.date_naive();
|
||
|
||
let mut ranges = Vec::new();
|
||
let mut fold = 0_usize;
|
||
|
||
loop {
|
||
let total_train_months = config
|
||
.initial_train_months
|
||
.saturating_add(fold as u32 * config.step_months);
|
||
let train_end = match data_start.checked_add_months(Months::new(total_train_months)) {
|
||
Some(d) => d,
|
||
None => break,
|
||
};
|
||
let val_end = match train_end.checked_add_months(Months::new(config.val_months)) {
|
||
Some(d) => d,
|
||
None => break,
|
||
};
|
||
let test_end = match val_end.checked_add_months(Months::new(config.test_months)) {
|
||
Some(d) => d,
|
||
None => break,
|
||
};
|
||
|
||
if test_end > data_end + chrono::Duration::days(1) {
|
||
break;
|
||
}
|
||
|
||
// O(log n) index lookups via partition_point (bars are sorted by timestamp)
|
||
let train_end_idx = bars.partition_point(|b| b.timestamp.date_naive() < train_end);
|
||
let val_end_idx = bars.partition_point(|b| b.timestamp.date_naive() < val_end);
|
||
let test_end_idx = bars.partition_point(|b| b.timestamp.date_naive() < test_end);
|
||
|
||
let train_start = 0; // expanding window: always starts at beginning
|
||
// Audit follow-up: insert PURGE_BARS gap between train and val
|
||
// to break single-bar carry-over from the last train label
|
||
// (`target = next_close`) into the first val state
|
||
// (`close`). Saturating-add against `bars.len()` so the purge
|
||
// can never push val past the end of the dataset; the
|
||
// `train_len >= MIN_BARS_PER_SPLIT` gate below catches degenerate
|
||
// folds where the purge consumes the entire validation window.
|
||
let val_start = train_end_idx
|
||
.saturating_add(PURGE_BARS)
|
||
.min(bars.len());
|
||
let val_end_bound = val_end_idx.max(val_start);
|
||
|
||
// Skip folds where any split is too small
|
||
let train_len = train_end_idx - train_start;
|
||
let val_len = val_end_bound - val_start;
|
||
let test_len = test_end_idx - val_end_bound;
|
||
|
||
if train_len < MIN_BARS_PER_SPLIT || val_len < MIN_BARS_PER_SPLIT || test_len < MIN_BARS_PER_SPLIT {
|
||
if val_len < MIN_BARS_PER_SPLIT || test_len < MIN_BARS_PER_SPLIT {
|
||
if fold > 0 { break; }
|
||
}
|
||
fold = fold.saturating_add(1);
|
||
continue;
|
||
}
|
||
|
||
let difficulty_score = compute_difficulty(&bars[train_start..train_end_idx]);
|
||
|
||
ranges.push(FoldRange {
|
||
fold,
|
||
train_start,
|
||
train_end: train_end_idx,
|
||
val_start,
|
||
val_end: val_end_bound,
|
||
difficulty_score,
|
||
});
|
||
|
||
fold = fold.saturating_add(1);
|
||
}
|
||
|
||
ranges
|
||
}
|
||
|
||
/// Generate walk-forward folds as index ranges from nanosecond timestamps.
|
||
///
|
||
/// Same date-boundary logic as [`generate_walk_forward_indices`] but operates
|
||
/// on raw `i64` timestamps (nanoseconds since Unix epoch) from fxcache data
|
||
/// instead of `OHLCVBar`. Difficulty score is always 0.0 because we don't
|
||
/// have OHLC data to compute ADX.
|
||
pub fn generate_walk_forward_indices_from_timestamps(
|
||
timestamps: &[i64],
|
||
config: &WalkForwardConfig,
|
||
) -> Vec<FoldRange> {
|
||
if timestamps.is_empty() {
|
||
return Vec::new();
|
||
}
|
||
|
||
let first_ts = timestamps[0];
|
||
let last_ts = timestamps[timestamps.len() - 1];
|
||
|
||
let data_start = chrono::DateTime::from_timestamp_nanos(first_ts).date_naive();
|
||
let data_end = chrono::DateTime::from_timestamp_nanos(last_ts).date_naive();
|
||
|
||
let mut ranges = Vec::new();
|
||
let mut fold = 0_usize;
|
||
|
||
loop {
|
||
let total_train_months = config
|
||
.initial_train_months
|
||
.saturating_add(fold as u32 * config.step_months);
|
||
let train_end = match data_start.checked_add_months(Months::new(total_train_months)) {
|
||
Some(d) => d,
|
||
None => break,
|
||
};
|
||
let val_end = match train_end.checked_add_months(Months::new(config.val_months)) {
|
||
Some(d) => d,
|
||
None => break,
|
||
};
|
||
let test_end = match val_end.checked_add_months(Months::new(config.test_months)) {
|
||
Some(d) => d,
|
||
None => break,
|
||
};
|
||
|
||
if test_end > data_end + chrono::Duration::days(1) {
|
||
break;
|
||
}
|
||
|
||
// O(log n) index lookups via partition_point (timestamps are sorted)
|
||
let train_end_idx = timestamps.partition_point(|&ts| {
|
||
chrono::DateTime::from_timestamp_nanos(ts).date_naive() < train_end
|
||
});
|
||
let val_end_idx = timestamps.partition_point(|&ts| {
|
||
chrono::DateTime::from_timestamp_nanos(ts).date_naive() < val_end
|
||
});
|
||
let test_end_idx = timestamps.partition_point(|&ts| {
|
||
chrono::DateTime::from_timestamp_nanos(ts).date_naive() < test_end
|
||
});
|
||
|
||
let train_start = 0; // expanding window: always starts at beginning
|
||
// Audit follow-up: insert PURGE_BARS gap between train and val
|
||
// to break single-bar carry-over (see PURGE_BARS docstring).
|
||
// Mirrors the bars-based variant above for the timestamps-only
|
||
// fxcache path; same saturating-add guard.
|
||
let val_start = train_end_idx
|
||
.saturating_add(PURGE_BARS)
|
||
.min(timestamps.len());
|
||
let val_end_bound = val_end_idx.max(val_start);
|
||
|
||
// Skip folds where any split is too small
|
||
let train_len = train_end_idx - train_start;
|
||
let val_len = val_end_bound - val_start;
|
||
let test_len = test_end_idx - val_end_bound;
|
||
|
||
if train_len < MIN_BARS_PER_SPLIT || val_len < MIN_BARS_PER_SPLIT || test_len < MIN_BARS_PER_SPLIT {
|
||
if val_len < MIN_BARS_PER_SPLIT || test_len < MIN_BARS_PER_SPLIT {
|
||
if fold > 0 { break; }
|
||
}
|
||
fold = fold.saturating_add(1);
|
||
continue;
|
||
}
|
||
|
||
// No ADX computation — fxcache doesn't have OHLC bars for difficulty
|
||
ranges.push(FoldRange {
|
||
fold,
|
||
train_start,
|
||
train_end: train_end_idx,
|
||
val_start,
|
||
val_end: val_end_bound,
|
||
difficulty_score: 0.0,
|
||
});
|
||
|
||
fold = fold.saturating_add(1);
|
||
}
|
||
|
||
ranges
|
||
}
|
||
|
||
/// Per-feature normalization statistics (mean and standard deviation).
|
||
///
|
||
/// Computed from training data and applied to val/test data to prevent
|
||
/// information leakage. Uses z-score normalization: `(x - mean) / std`.
|
||
#[derive(Debug, Clone, serde::Serialize, serde::Deserialize)]
|
||
pub struct NormStats {
|
||
/// Per-feature mean values (length 51).
|
||
pub mean: Vec<f64>,
|
||
/// Per-feature standard deviation values (length 51, clamped >= 1e-8).
|
||
pub std: Vec<f64>,
|
||
}
|
||
|
||
/// Number of features in a standard feature vector (42 market features: 40 base + 2 regime).
|
||
const FEATURE_DIM: usize = 42;
|
||
|
||
/// Minimum standard deviation to prevent division by zero.
|
||
const MIN_STD: f64 = 1e-8;
|
||
|
||
/// Train→Val purge gap (in bars) inserted between every fold's train and
|
||
/// val windows. Audit follow-up
|
||
/// `docs/lookahead-bias-audit-2026-04-28.md` rec 2 — without a gap, the
|
||
/// last training bar's `target = next_close` overlaps the first val
|
||
/// bar's `close`, producing single-bar carry-over correlation between
|
||
/// the train label and the immediately-following val state. The 5-bar
|
||
/// width is the minimum that breaks single-bar carry-over for all
|
||
/// per-bar features (autocorr lags 1/5/10 at `extraction.rs:484-491`,
|
||
/// price-acceleration window 3 at `extraction.rs:797-810`); going
|
||
/// wider would reduce val sample size without measurable lookahead
|
||
/// reduction. Bar-count rather than time-based purge: at volume-bar
|
||
/// cadence bars vary in time, but 5 consecutive bars consume any
|
||
/// per-bar features regardless of wall-clock spacing — the lookahead
|
||
/// surface is per-bar, so per-bar purge is the well-matched primitive.
|
||
///
|
||
/// This is a structural correctness anchor rather than an adaptive
|
||
/// constant: the value is determined by the maximum lookback of the
|
||
/// feature pipeline (5 bars), not by training dynamics. Per
|
||
/// `feedback_isv_for_adaptive_bounds` it stays compile-time because
|
||
/// the feature-pipeline lookback is itself compile-time.
|
||
pub const PURGE_BARS: usize = 5;
|
||
|
||
/// Maximum legitimate magnitude of a z-score-normalized feature.
|
||
///
|
||
/// Z-scores in real-market 42-dim feature vectors live well within ±5 even on
|
||
/// extreme bars (10σ events are vanishingly rare); ±20 is a generous ceiling
|
||
/// that traps every observed corruption pattern (raw-price leak, corrupt bar
|
||
/// with log_return = -30 / std=1e-3 = -30000, etc.) without rejecting any
|
||
/// legitimate market signal. Used as the shared invariant in
|
||
/// [`validate_normalized_features`].
|
||
pub const NORMALIZED_FEATURE_BOUND: f64 = 20.0;
|
||
|
||
impl NormStats {
|
||
/// Compute normalization statistics from a batch of feature vectors (FEATURE_DIM dimensions).
|
||
///
|
||
/// If the input is empty, returns mean = 0.0 and std = 1.0 for all features.
|
||
pub fn from_features(features: &[[f64; FEATURE_DIM]]) -> Self {
|
||
if features.is_empty() {
|
||
return Self {
|
||
mean: vec![0.0; FEATURE_DIM],
|
||
std: vec![1.0; FEATURE_DIM],
|
||
};
|
||
}
|
||
|
||
let n = features.len() as f64;
|
||
let mut mean = vec![0.0_f64; FEATURE_DIM];
|
||
let mut variance = vec![0.0_f64; FEATURE_DIM];
|
||
|
||
// Accumulate sums for mean
|
||
for feature_vec in features {
|
||
for (m, val) in mean.iter_mut().zip(feature_vec.iter()) {
|
||
*m += val;
|
||
}
|
||
}
|
||
|
||
// Compute mean
|
||
for m in &mut mean {
|
||
*m /= n;
|
||
}
|
||
|
||
// Accumulate variance
|
||
for feature_vec in features {
|
||
for (v, (val, m)) in variance
|
||
.iter_mut()
|
||
.zip(feature_vec.iter().zip(mean.iter()))
|
||
{
|
||
let diff = val - m;
|
||
*v += diff * diff;
|
||
}
|
||
}
|
||
|
||
// Compute std with minimum clamp
|
||
let std_vec: Vec<f64> = variance
|
||
.iter()
|
||
.map(|v| (v / n).sqrt().max(MIN_STD))
|
||
.collect();
|
||
|
||
Self {
|
||
mean,
|
||
std: std_vec,
|
||
}
|
||
}
|
||
|
||
/// Compute normalization statistics from a contiguous SLICE of feature
|
||
/// vectors (the fold's train range). Audit follow-up
|
||
/// `docs/lookahead-bias-audit-2026-04-28.md` rec 3 — fitting `NormStats`
|
||
/// only on the training portion of each fold prevents val-window
|
||
/// statistics from leaking into the train-time z-score baseline. The
|
||
/// trainer fold loop uses this in place of the global `from_features`
|
||
/// fit to satisfy "Compute stats from training data only" (the
|
||
/// docstring contract at the top of this module).
|
||
///
|
||
/// `train_start..train_end` is the half-open range of bar indices to
|
||
/// fit on; the resulting stats are then applied to BOTH train and val
|
||
/// portions of the same fold via `normalize_batch`. Behaves identically
|
||
/// to `from_features(&features[train_start..train_end])` but takes a
|
||
/// borrow rather than forcing the caller to slice; useful when the
|
||
/// caller already owns the full feature buffer and wants per-fold fits
|
||
/// without extra allocation.
|
||
pub fn from_features_slice(
|
||
features: &[[f64; FEATURE_DIM]],
|
||
train_start: usize,
|
||
train_end: usize,
|
||
) -> Self {
|
||
let end = train_end.min(features.len());
|
||
let start = train_start.min(end);
|
||
Self::from_features(&features[start..end])
|
||
}
|
||
|
||
/// Z-score normalize a single 42-dimensional feature vector.
|
||
///
|
||
/// Returns `clamp((feature - mean) / std, ±NORMALIZED_FEATURE_BOUND)`
|
||
/// element-wise. The clamp is the structural guarantee that downstream GPU
|
||
/// consumers (state_gather → state[0] in `experience_state_gather`, aux
|
||
/// label_scale_ema, vol_normalizer) see bounded inputs regardless of what
|
||
/// corruption survives upstream. Without it, a single outlier from a
|
||
/// corrupt DBN bar inflates `std` enough to amplify itself by sqrt(N) post-
|
||
/// normalization and flow through training as a ±30000 magnitude state[0]
|
||
/// outlier.
|
||
pub fn normalize(&self, features: &[f64; FEATURE_DIM]) -> [f64; FEATURE_DIM] {
|
||
let mut result = [0.0_f64; FEATURE_DIM];
|
||
for ((r, val), (m, s)) in result
|
||
.iter_mut()
|
||
.zip(features.iter())
|
||
.zip(self.mean.iter().zip(self.std.iter()))
|
||
{
|
||
*r = ((val - m) / s).clamp(-NORMALIZED_FEATURE_BOUND, NORMALIZED_FEATURE_BOUND);
|
||
}
|
||
result
|
||
}
|
||
|
||
/// Z-score normalize a batch of 42-dimensional feature vectors.
|
||
pub fn normalize_batch(&self, features: &[[f64; FEATURE_DIM]]) -> Vec<[f64; FEATURE_DIM]> {
|
||
features.iter().map(|f| self.normalize(f)).collect()
|
||
}
|
||
|
||
/// In-place variant of `normalize_batch`: rewrites `features` rather
|
||
/// than allocating a new Vec. Saves a transient ~6GB peak when
|
||
/// `features` is the precompute_features pass over 17.8M bars
|
||
/// (which previously held both the pre- and post-normalised arrays
|
||
/// alive simultaneously while `.collect()` built the new one).
|
||
pub fn normalize_batch_in_place(&self, features: &mut [[f64; FEATURE_DIM]]) {
|
||
for f in features.iter_mut() {
|
||
*f = self.normalize(f);
|
||
}
|
||
}
|
||
|
||
/// Inverse of `normalize`: recover raw `feature` from a previously-
|
||
/// normalised value via `raw = norm * std + mean`. Caveat: the forward
|
||
/// path applies `clamp(±NORMALIZED_FEATURE_BOUND)` post-divide, so any
|
||
/// normalised value sitting at exactly ±20 is information-lossy under
|
||
/// this inverse (the original z-score may have been larger, but the
|
||
/// raw value pointer is gone). For the per-fold renormalisation flow
|
||
/// in `train_baseline_rl.rs` (audit fix rec 3) this matters only at
|
||
/// outlier boundaries; non-clamped bars round-trip exactly. The
|
||
/// alternative — storing raw features in fxcache — requires bumping
|
||
/// `FXCACHE_VERSION` and migrating all consumers atomically; see the
|
||
/// fxcache header docstring for the version-bump rationale.
|
||
pub fn denormalize(&self, normalised: &[f64; FEATURE_DIM]) -> [f64; FEATURE_DIM] {
|
||
let mut result = [0.0_f64; FEATURE_DIM];
|
||
for ((r, val), (m, s)) in result
|
||
.iter_mut()
|
||
.zip(normalised.iter())
|
||
.zip(self.mean.iter().zip(self.std.iter()))
|
||
{
|
||
*r = val * s + m;
|
||
}
|
||
result
|
||
}
|
||
|
||
/// Batched inverse of `normalize_batch`. See `denormalize` for the
|
||
/// clamp caveat.
|
||
pub fn denormalize_batch(&self, normalised: &[[f64; FEATURE_DIM]]) -> Vec<[f64; FEATURE_DIM]> {
|
||
normalised.iter().map(|f| self.denormalize(f)).collect()
|
||
}
|
||
}
|
||
|
||
/// Validate that a batch of normalized features is bounded and free of NaN/Inf.
|
||
///
|
||
/// Single source of truth for the post-normalization invariant — used by both
|
||
/// the fxcache fast path (after `discover_and_load`) and the DBN fallback
|
||
/// (after `normalize_batch`). Either path producing data that fails this gate
|
||
/// must error out rather than upload poisoned values to the GPU.
|
||
///
|
||
/// Returns `Ok(())` if every element of every vector is finite and within
|
||
/// `±NORMALIZED_FEATURE_BOUND`. On the first violation, returns an `Err` with
|
||
/// the bar index, feature index, and value so the operator can locate the
|
||
/// corrupt source row.
|
||
pub fn validate_normalized_features(
|
||
features: &[[f64; FEATURE_DIM]],
|
||
source: &str,
|
||
) -> anyhow::Result<()> {
|
||
for (bar_idx, feat_vec) in features.iter().enumerate() {
|
||
for (feat_idx, &val) in feat_vec.iter().enumerate() {
|
||
if !val.is_finite() {
|
||
anyhow::bail!(
|
||
"{source}: non-finite value at bar={bar_idx}, feat={feat_idx}: {val} \
|
||
— data corruption between source and post-normalization."
|
||
);
|
||
}
|
||
if val.abs() > NORMALIZED_FEATURE_BOUND {
|
||
anyhow::bail!(
|
||
"{source}: |feature[{bar_idx}][{feat_idx}]| = {} exceeds normalized bound \
|
||
(±{NORMALIZED_FEATURE_BOUND}) — corrupt bar (e.g. bar.open ≈ 0 producing \
|
||
extreme log return) or unit-mismatch (raw price written instead of \
|
||
z-normalized log return). Reject the dataset; do not upload to GPU.",
|
||
val
|
||
);
|
||
}
|
||
}
|
||
}
|
||
Ok(())
|
||
}
|
||
|
||
#[cfg(test)]
|
||
mod tests {
|
||
use super::*;
|
||
use chrono::{Datelike, NaiveDate, NaiveTime, TimeZone, Utc, Weekday};
|
||
|
||
/// Create a single OHLCV bar at the given date.
|
||
fn make_bar(year: i32, month: u32, day: u32) -> OHLCVBar {
|
||
let date = NaiveDate::from_ymd_opt(year, month, day).unwrap_or_default();
|
||
let time = NaiveTime::from_hms_opt(10, 0, 0).unwrap_or_default();
|
||
let dt = date.and_time(time);
|
||
let timestamp = Utc.from_utc_datetime(&dt);
|
||
OHLCVBar {
|
||
timestamp,
|
||
open: 100.0,
|
||
high: 101.0,
|
||
low: 99.0,
|
||
close: 100.5,
|
||
volume: 1000.0,
|
||
}
|
||
}
|
||
|
||
/// Create bars for every weekday in [start, end) with one bar per day.
|
||
/// For testing purposes, this creates enough density to exceed the minimum
|
||
/// bars threshold when covering multi-month ranges.
|
||
fn make_bars_range(start: NaiveDate, end: NaiveDate) -> Vec<OHLCVBar> {
|
||
let mut bars = Vec::new();
|
||
let mut current = start;
|
||
let time = NaiveTime::from_hms_opt(10, 0, 0).unwrap_or_default();
|
||
while current < end {
|
||
let weekday = current.weekday();
|
||
if weekday != Weekday::Sat && weekday != Weekday::Sun {
|
||
// Generate multiple bars per trading day to simulate 1-min bars
|
||
// We need enough density: ~390 bars per day for 6.5h of trading
|
||
// For test efficiency, generate 20 bars per day (enough for density)
|
||
for minute_offset in 0..20 {
|
||
let bar_time =
|
||
NaiveTime::from_hms_opt(9, 30_u32.saturating_add(minute_offset), 0)
|
||
.unwrap_or(time);
|
||
let dt = current.and_time(bar_time);
|
||
let timestamp = Utc.from_utc_datetime(&dt);
|
||
bars.push(OHLCVBar {
|
||
timestamp,
|
||
open: 100.0 + (bars.len() as f64 * 0.001),
|
||
high: 101.0 + (bars.len() as f64 * 0.001),
|
||
low: 99.0 + (bars.len() as f64 * 0.001),
|
||
close: 100.5 + (bars.len() as f64 * 0.001),
|
||
volume: 1000.0,
|
||
});
|
||
}
|
||
}
|
||
current = current
|
||
.succ_opt()
|
||
.unwrap_or(current);
|
||
}
|
||
bars
|
||
}
|
||
|
||
#[test]
|
||
fn test_generate_walk_forward_empty_bars() {
|
||
let config = WalkForwardConfig::default();
|
||
let windows = generate_walk_forward_windows(&[], &config);
|
||
assert!(windows.is_empty());
|
||
}
|
||
|
||
#[test]
|
||
fn test_walk_forward_windows_24_months() {
|
||
// Generate 24 months of synthetic bars
|
||
let start = NaiveDate::from_ymd_opt(2023, 1, 1).unwrap_or_default();
|
||
let end = NaiveDate::from_ymd_opt(2025, 1, 1).unwrap_or_default();
|
||
let bars = make_bars_range(start, end);
|
||
|
||
assert!(
|
||
!bars.is_empty(),
|
||
"Should have generated bars for 24-month range"
|
||
);
|
||
|
||
let config = WalkForwardConfig::default(); // 12/3/3/3
|
||
let windows = generate_walk_forward_windows(&bars, &config);
|
||
|
||
// With 24 months of data and 12+3+3=18 months for first fold, stepping by 3:
|
||
// Fold 0: train 12mo, val 3mo, test 3mo = 18 months (fits in 24)
|
||
// Fold 1: train 15mo, val 3mo, test 3mo = 21 months (fits in 24)
|
||
// Fold 2: train 18mo, val 3mo, test 3mo = 24 months (might barely fit)
|
||
assert!(
|
||
windows.len() >= 2,
|
||
"Expected at least 2 windows, got {}",
|
||
windows.len()
|
||
);
|
||
|
||
// Check fold 0 has non-empty splits
|
||
if let Some(w0) = windows.first() {
|
||
assert!(!w0.train.is_empty(), "Fold 0 train should be non-empty");
|
||
assert!(!w0.val.is_empty(), "Fold 0 val should be non-empty");
|
||
assert!(!w0.test.is_empty(), "Fold 0 test should be non-empty");
|
||
|
||
// Train must end before val
|
||
assert!(
|
||
w0.train_end <= w0.val_end,
|
||
"Train end ({}) should be <= val end ({})",
|
||
w0.train_end,
|
||
w0.val_end
|
||
);
|
||
}
|
||
}
|
||
|
||
#[test]
|
||
fn test_walk_forward_expanding_windows() {
|
||
// Generate 30 months to get multiple folds
|
||
let start = NaiveDate::from_ymd_opt(2023, 1, 1).unwrap_or_default();
|
||
let end = NaiveDate::from_ymd_opt(2025, 7, 1).unwrap_or_default();
|
||
let bars = make_bars_range(start, end);
|
||
|
||
let config = WalkForwardConfig::default();
|
||
let windows = generate_walk_forward_windows(&bars, &config);
|
||
|
||
assert!(
|
||
windows.len() >= 2,
|
||
"Need at least 2 windows to test expanding, got {}",
|
||
windows.len()
|
||
);
|
||
|
||
// Each successive fold should have strictly more training data
|
||
for pair in windows.windows(2) {
|
||
let (prev, next) = match (pair.first(), pair.get(1)) {
|
||
(Some(p), Some(n)) => (p, n),
|
||
_ => continue,
|
||
};
|
||
assert!(
|
||
next.train.len() > prev.train.len(),
|
||
"Fold {} train ({} bars) should have more data than fold {} train ({} bars)",
|
||
next.fold,
|
||
next.train.len(),
|
||
prev.fold,
|
||
prev.train.len()
|
||
);
|
||
}
|
||
}
|
||
|
||
#[test]
|
||
fn test_norm_stats_roundtrip() {
|
||
// Features: [[1,1,...], [2,2,...], [3,3,...]]
|
||
let f1 = [1.0_f64; FEATURE_DIM];
|
||
let f2 = [2.0_f64; FEATURE_DIM];
|
||
let f3 = [3.0_f64; FEATURE_DIM];
|
||
let features = [f1, f2, f3];
|
||
|
||
let stats = NormStats::from_features(&features);
|
||
|
||
// Mean should be 2.0 for all features
|
||
for m in &stats.mean {
|
||
assert!(
|
||
(*m - 2.0).abs() < 1e-10,
|
||
"Expected mean ~2.0, got {}",
|
||
m
|
||
);
|
||
}
|
||
|
||
// Normalizing the mean vector should give ~0 for all features
|
||
let normalized = stats.normalize(&f2);
|
||
for val in &normalized {
|
||
assert!(
|
||
val.abs() < 1e-10,
|
||
"Expected normalized mean ~0.0, got {}",
|
||
val
|
||
);
|
||
}
|
||
}
|
||
|
||
#[test]
|
||
fn test_norm_stats_empty() {
|
||
let features: &[[f64; FEATURE_DIM]] = &[];
|
||
let stats = NormStats::from_features(features);
|
||
|
||
// Should return safe defaults
|
||
assert_eq!(stats.mean.len(), FEATURE_DIM);
|
||
assert_eq!(stats.std.len(), FEATURE_DIM);
|
||
|
||
// Mean should be 0.0
|
||
for m in &stats.mean {
|
||
assert!((*m).abs() < 1e-10, "Expected mean 0.0, got {}", m);
|
||
}
|
||
|
||
// Std should be 1.0
|
||
for s in &stats.std {
|
||
assert!(
|
||
(*s - 1.0).abs() < 1e-10,
|
||
"Expected std 1.0, got {}",
|
||
s
|
||
);
|
||
}
|
||
}
|
||
|
||
/// Audit follow-up `docs/lookahead-bias-audit-2026-04-28.md` rec 3
|
||
/// behavioral test: per-fold `from_features_slice` must fit on
|
||
/// train-only data, NOT the global mean that includes val. Builds a
|
||
/// synthetic dataset where the train portion has mean 1.0 per
|
||
/// feature and the val portion has mean 9.0 per feature; the
|
||
/// global mean would be 5.0. Verifies the per-fold helper recovers
|
||
/// the train-only mean to ε=1e-5.
|
||
#[test]
|
||
fn test_norm_stats_per_fold_fit_train_only() {
|
||
const TRAIN_END: usize = 100;
|
||
const VAL_END: usize = 200;
|
||
const EPS: f64 = 1e-5;
|
||
|
||
// Build features where train slice [0..100) has mean 1.0 and
|
||
// val slice [100..200) has mean 9.0. Global mean would be 5.0.
|
||
let mut features: Vec<[f64; FEATURE_DIM]> = Vec::with_capacity(VAL_END);
|
||
for _ in 0..TRAIN_END {
|
||
features.push([1.0_f64; FEATURE_DIM]);
|
||
}
|
||
for _ in TRAIN_END..VAL_END {
|
||
features.push([9.0_f64; FEATURE_DIM]);
|
||
}
|
||
|
||
// Per-fold fit (audit-correct path).
|
||
let per_fold = NormStats::from_features_slice(&features, 0, TRAIN_END);
|
||
for (i, m) in per_fold.mean.iter().enumerate() {
|
||
assert!(
|
||
(m - 1.0).abs() < EPS,
|
||
"per-fold feat[{i}] mean: got {m}, expected 1.0 (train-only)"
|
||
);
|
||
}
|
||
|
||
// Global fit (audit-flagged path).
|
||
let global = NormStats::from_features(&features);
|
||
for (i, m) in global.mean.iter().enumerate() {
|
||
assert!(
|
||
(m - 5.0).abs() < EPS,
|
||
"global feat[{i}] mean: got {m}, expected 5.0 (train + val)"
|
||
);
|
||
}
|
||
|
||
// The two fits must produce DIFFERENT means — that's the whole
|
||
// point of the rec 3 fix. ε=1e-5 is the audit's behavioral
|
||
// contract.
|
||
let mean_diff = (per_fold.mean[0] - global.mean[0]).abs();
|
||
assert!(
|
||
mean_diff > 1.0,
|
||
"per-fold and global means must differ for shifted-val test: \
|
||
per_fold.mean[0]={}, global.mean[0]={}",
|
||
per_fold.mean[0],
|
||
global.mean[0]
|
||
);
|
||
}
|
||
|
||
/// Round-trip via denormalize → normalize: any feature within the
|
||
/// non-clamped range should recover bit-identically. Pins the
|
||
/// invariant that `train_baseline_rl.rs`'s per-fold renormalisation
|
||
/// helper preserves data fidelity for in-distribution bars.
|
||
#[test]
|
||
fn test_norm_stats_denormalize_roundtrip() {
|
||
let f1 = [1.0_f64; FEATURE_DIM];
|
||
let f2 = [2.0_f64; FEATURE_DIM];
|
||
let f3 = [3.0_f64; FEATURE_DIM];
|
||
let features = [f1, f2, f3];
|
||
|
||
let stats = NormStats::from_features(&features);
|
||
let normalised = stats.normalize_batch(&features);
|
||
let recovered = stats.denormalize_batch(&normalised);
|
||
|
||
for (orig, rec) in features.iter().zip(recovered.iter()) {
|
||
for (o, r) in orig.iter().zip(rec.iter()) {
|
||
assert!(
|
||
(o - r).abs() < 1e-10,
|
||
"denormalize round-trip: orig={o}, recovered={r}"
|
||
);
|
||
}
|
||
}
|
||
}
|
||
|
||
/// Audit follow-up rec 2: PURGE_BARS gap between train and val.
|
||
/// Verifies that `generate_walk_forward_indices_from_timestamps`
|
||
/// inserts `val_start = train_end + PURGE_BARS` (not `train_end`).
|
||
/// Uses synthetic timestamps spanning enough months to produce a
|
||
/// valid fold under the default config.
|
||
#[test]
|
||
fn test_walk_forward_purge_gap_indices_from_timestamps() {
|
||
// Generate 30 months of dense timestamps (1 ts per minute, 8h
|
||
// per weekday) — same density convention as `make_bars_range`.
|
||
let start = NaiveDate::from_ymd_opt(2023, 1, 1).unwrap_or_default();
|
||
let end = NaiveDate::from_ymd_opt(2025, 7, 1).unwrap_or_default();
|
||
let bars = make_bars_range(start, end);
|
||
let timestamps: Vec<i64> = bars
|
||
.iter()
|
||
.map(|b| b.timestamp.timestamp_nanos_opt().unwrap_or(0))
|
||
.collect();
|
||
|
||
let config = WalkForwardConfig::default();
|
||
let ranges = generate_walk_forward_indices_from_timestamps(×tamps, &config);
|
||
assert!(!ranges.is_empty(), "expected at least one fold");
|
||
|
||
for r in &ranges {
|
||
assert_eq!(
|
||
r.val_start - r.train_end,
|
||
PURGE_BARS,
|
||
"fold {}: val_start({}) - train_end({}) must equal PURGE_BARS({}) — \
|
||
audit rec 2 lookahead gap",
|
||
r.fold,
|
||
r.val_start,
|
||
r.train_end,
|
||
PURGE_BARS
|
||
);
|
||
}
|
||
}
|
||
}
|