logaritmiskandClaude Opus 5
9b2c2b38c8
Closes the last open item in #25. `cargo clippy -W missing_errors_doc -W missing_panics_doc -W must_use_candidate -W doc_markdown` went from 56 warnings to zero. The 13 hand-written sections name the actual variants each function returns rather than gesturing at "an error". Establishing that meant reading the error paths — `Game::ranked` alone returns four distinct variants, and `record_draw` can hit TieWithoutDrawProbability where `record_winner` provably cannot, since a two-team decisive outcome has nothing to tie. Documenting those as interchangeable would have been worse than leaving them undocumented, because a reader would trust it. Two existing doc comments already described panics in prose but not under a `# Panics` heading, so neither rustdoc nor clippy surfaced them: `Outcome::winner` and `EventBuilder::weights`. Both now carry the heading, and `Outcome::winner` gained the note that it ties every loser, so `n >= 3` needs a positive p_draw — the crate's easiest error to hit by accident. The 43 mechanical fixes (31 `#[must_use]` on pure accessors, 11 missing backticks) were applied with `cargo clippy --fix`. `#[must_use]` on Gaussian's arithmetic and on `posteriors()` matters: discarding those results is always a bug, and until now nothing said so. Also documented why `[profile.release] debug = true` exists — cargo-flamegraph needs the symbols, and library profile settings are ignored downstream, so it reads as an oversight without the note. Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01T5SYDExxL4vZgvunrcNSMc
96 lines
2.9 KiB
Rust
96 lines
2.9 KiB
Rust
use crate::factor::{Factor, VarId, VarStore};
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/// Maintains the constraint `diff = team_a - team_b` between three vars.
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///
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/// On each propagation:
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/// - Reads marginals at `team_a` and `team_b` (which already incorporate any
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/// incoming messages from neighboring factors).
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/// - Computes `new_diff = team_a - team_b` (variance addition; see `Gaussian::Sub`).
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/// - Writes the new marginal to `diff`.
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/// - Returns the delta against the previous diff value.
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///
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/// This factor does NOT store an outgoing message; the diff variable is
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/// effectively replaced on each propagation. The `TruncFactor` on the same diff
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/// var holds the EP-divide message that produces the cavity.
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#[derive(Debug)]
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pub struct RankDiffFactor {
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pub team_a: VarId,
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pub team_b: VarId,
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pub diff: VarId,
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}
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impl Factor for RankDiffFactor {
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fn propagate(&mut self, vars: &mut VarStore) -> (f64, f64) {
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let a = vars.get(self.team_a);
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let b = vars.get(self.team_b);
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let new_diff = a - b;
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let old = vars.get(self.diff);
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vars.set(self.diff, new_diff);
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old.delta(new_diff)
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}
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}
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#[cfg(test)]
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mod tests {
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use super::*;
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use crate::{N_INF, gaussian::Gaussian};
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#[test]
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fn diff_of_two_known_gaussians() {
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let mut vars = VarStore::new();
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let team_a = vars.alloc(Gaussian::from_ms(25.0, 3.0));
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let team_b = vars.alloc(Gaussian::from_ms(20.0, 4.0));
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let diff = vars.alloc(N_INF);
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let mut f = RankDiffFactor {
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team_a,
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team_b,
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diff,
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};
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f.propagate(&mut vars);
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let result = vars.get(diff);
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// mu = 25 - 20 = 5; var = 9 + 16 = 25; sigma = 5
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assert!((result.mu() - 5.0).abs() < 1e-12);
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assert!((result.sigma() - 5.0).abs() < 1e-12);
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}
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#[test]
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fn delta_zero_on_repeat() {
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let mut vars = VarStore::new();
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let team_a = vars.alloc(Gaussian::from_ms(10.0, 2.0));
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let team_b = vars.alloc(Gaussian::from_ms(8.0, 1.0));
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let diff = vars.alloc(N_INF);
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let mut f = RankDiffFactor {
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team_a,
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team_b,
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diff,
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};
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f.propagate(&mut vars);
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let (dmu, dsig) = f.propagate(&mut vars);
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assert!(dmu < 1e-12);
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assert!(dsig < 1e-12);
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}
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#[test]
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fn delta_reflects_team_change() {
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let mut vars = VarStore::new();
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let team_a = vars.alloc(Gaussian::from_ms(10.0, 1.0));
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let team_b = vars.alloc(Gaussian::from_ms(0.0, 1.0));
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let diff = vars.alloc(N_INF);
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let mut f = RankDiffFactor {
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team_a,
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team_b,
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diff,
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};
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f.propagate(&mut vars);
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// change team_a, repropagate; delta should be positive
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vars.set(team_a, Gaussian::from_ms(15.0, 1.0));
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let (dmu, _dsig) = f.propagate(&mut vars);
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assert!(dmu > 4.0, "expected ~5 delta, got {}", dmu);
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}
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}
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