Fine-Tuning

Fine-tuning is an optional phase after surrogate-based optimization.

Purpose

Surrogate optimization is fast. Fine-tuning adds higher-fidelity EM verification and refinement.

Requirements

• Palace installed and callable.
• ORCA geometry object available in Python workflow.

Enabling Fine-Tuning

Fine-tuning behavior is configured via COBRA(...) constructor arguments and cobra.run(...) context.

Key options:

• palace_fine_tuning_command
• fine_tuning_iterations
• fine_tuning_optimizer

Fine-Tuning Optimizer Modes

• reuse: continue using the surrogate-phase optimizer.
• gradient_descent: switch to local gradient-descent refinement.

High-Level Loop

1. Build geometry from current best parameters.
2. Generate/mesh EM model.
3. Run Palace.
4. Feed verified response back to goal checker.
5. Continue until goals are met or iteration budget is exhausted.

Warning

Fine-tuning requires a correctly configured external EM environment and may be significantly slower than surrogate-only optimization.