Manuel Raimann
ee59c9cdd0
- Split pruning_and_callbacks into pruning and early_stopping - Split advanced_features into async_parallel, journal_storage, ask_and_tell, multi_objective - Each example now requires only its own feature flag - Trim sampler_comparison winner logic and verbose header - Update CI workflow and README to match new example names
44 lines
1.2 KiB
Rust
44 lines
1.2 KiB
Rust
//! Early stopping — halt an entire study once a target is reached.
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//!
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//! Use `optimize_with_callback` to inspect each completed trial and return
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//! `ControlFlow::Break(())` when the study should stop (e.g. a quality
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//! threshold is met or a time budget is exhausted).
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//!
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//! Run with: `cargo run --example early_stopping`
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use std::ops::ControlFlow;
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use optimizer::prelude::*;
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fn main() -> optimizer::Result<()> {
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let study: Study<f64> = Study::new(Direction::Minimize);
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let x = FloatParam::new(-10.0, 10.0).name("x");
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let target = 0.01;
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study.optimize_with_callback(
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100, // upper bound — we expect to stop much earlier
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|trial| {
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let xv = x.suggest(trial)?;
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Ok::<_, Error>((xv - 3.0).powi(2))
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},
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|_study, completed| {
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if completed.value < target {
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println!("Target {target} reached at trial #{}", completed.id);
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return ControlFlow::Break(());
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}
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ControlFlow::Continue(())
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},
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)?;
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let best = study.best_trial()?;
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println!(
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"Stopped after {} trials — best f({:.4}) = {:.6}",
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study.n_trials(),
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best.get(&x).unwrap(),
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best.value,
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);
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Ok(())
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}
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