Files
foxhunt/crates/ml-explainability/Cargo.toml
jgrusewski 82dca76dae feat(explainability): post-hoc IG diagnostic CLI for DQN checkpoints
Adds `ig_diag` binary under ml-explainability/src/bin/ that runs
Integrated Gradients on a trained DQN safetensors checkpoint and
writes a per-feature attribution report as JSON. Designed for offline
model inspection, not the inference hot path.

Forward target: mean(Q[direction, 0..4]), which simplifies to V(s)
under the dueling identity (mean of centered advantages is zero by
the identifiability constraint). Smooth, no argmax discontinuity,
well-posed for IG.

Regime-head handling: loads only the `trending__`-prefixed weights
(matches RegimeConditionalDQN::load_from_merged_safetensors). Full
multi-head attribution is a future extension.

CLI args:
  --checkpoint PATH        safetensors file
  --states auto|PATH       `auto` samples from test_data/feature-cache/
                           *.fxcache; otherwise a JSON file containing
                           { "states": [[f32; STATE_DIM], ...] }
  --feature-names PATH     JSON array of STATE_DIM names (optional)
  --num-steps N            IG Riemann steps (default 50)
  --output PATH            output JSON (default ig_report.json)
  --auto-samples N         fxcache sample count (default 16)
  --seed N                 LCG seed for reproducibility (default 42)

Output JSON schema:
  {
    "schema_version": 1,
    "checkpoint", "num_steps", "state_dim", "num_states",
    "forward_target", "regime_head",
    "features": [ { "name", "mean_abs", "stddev", "mean_signed" } ],
    "top_10_by_mean_abs": [...],
    "completeness": {
      "worst_relative_error": f64,
      "per_state": [ { "state_idx", "sum_attributions",
                       "f_input_minus_f_baseline", "relative_error" } ]
    }
  }

NoisyNet is disabled on both the Q-network and target network before
IG runs so attributions are deterministic (same checkpoint + states +
num_steps = bit-identical attributions).

Gated behind the `ig-diag-cli` Cargo feature (optional Cargo binary
feature, not a runtime flag) because the binary depends on ml-dqn.
Cannot depend on `ml` due to a cyclic dependency (ml already depends
on ml-explainability). To avoid pulling in the heavy `ml` crate, the
fxcache header parser is reimplemented inline in the binary (~80 LOC,
matches ml/src/fxcache.rs byte-for-byte for v4 files).

Tests:
- tests/ig_diag_cli_integration.rs: end-to-end test that builds a
  DQN, saves a checkpoint, writes a states JSON, invokes the binary
  via std::process::Command, parses the output, asserts schema +
  completeness axiom (worst relative error < 5%). Gated with
  #[cfg(all(feature = "cuda", feature = "ig-diag-cli"))] + #[ignore]
  because it needs CUDA + the binary pre-built.

Build/run:
  cargo build --release -p ml-explainability \
    --features ig-diag-cli --bin ig_diag
  cargo test -p ml-explainability --features ig-diag-cli \
    --test ig_diag_cli_integration -- --ignored --nocapture

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
2026-04-23 10:35:48 +02:00

63 lines
2.1 KiB
TOML

[package]
name = "ml-explainability"
version.workspace = true
edition.workspace = true
rust-version.workspace = true
authors.workspace = true
license.workspace = true
repository.workspace = true
homepage.workspace = true
documentation.workspace = true
publish.workspace = true
keywords.workspace = true
categories.workspace = true
description = "Model explainability (integrated gradients) for Foxhunt ML"
[features]
default = ["cuda"]
cuda = ["ml-core/cuda", "cudarc"]
# Standalone diagnostic binary. Gated with an optional Cargo feature so the
# library target stays minimal; enabling `ig-diag-cli` pulls in ml-dqn +
# argument parsing + JSON serialization for the `ig_diag` bin target.
ig-diag-cli = [
"cuda",
"dep:ml-dqn",
"dep:clap",
"dep:serde_json",
"dep:anyhow",
"dep:tracing",
"dep:tracing-subscriber",
]
[dependencies]
ml-core = { path = "../ml-core", default-features = false }
cudarc = { version = "0.19", optional = true, default-features = false, features = ["driver", "dynamic-linking", "std", "cuda-version-from-build-system"] }
# ig_diag binary deps (optional — only compiled with `--features ig-diag-cli`).
# NOTE: Cannot depend on `ml` here — it would create a cyclic dependency
# (ml already depends on ml-explainability). The CLI reads fxcache files
# directly (header parsing is trivial, see src/bin/ig_diag.rs).
ml-dqn = { path = "../ml-dqn", optional = true }
clap = { workspace = true, optional = true }
serde_json = { workspace = true, optional = true }
anyhow = { workspace = true, optional = true }
tracing = { workspace = true, optional = true }
tracing-subscriber = { workspace = true, optional = true }
[dev-dependencies]
tempfile = "3"
# The ig_diag CLI integration test drives the binary end-to-end: it needs
# ml-dqn + safetensors + serde_json to build a checkpoint and parse the
# report. These are only used by tests (no library impact).
ml-dqn = { path = "../ml-dqn" }
safetensors = "0.7"
serde_json = { workspace = true }
[[bin]]
name = "ig_diag"
path = "src/bin/ig_diag.rs"
required-features = ["ig-diag-cli"]
[lints]
workspace = true