Local Search and Optimisation
Local Search and Optimisation #
Local search improves one or a few complete candidate solutions by moving through their neighbourhoods. It is especially useful when the final configuration matters but the path used to reach it does not.
– Local Search Algorithms & Optimisation Problems
- Hill Climbing Search
- Local Beam Search
- Online Search Agents
Learning Objectives #
- distinguish path optimisation from state optimisation
- explain states, neighbours and objective functions
- apply hill climbing and its variants
- recognise local maxima, plateaus and ridges
- explain random-restart and stochastic hill climbing
- describe local and stochastic beam search and trace one beam update
Big Picture #
flowchart TD
S["Current state"] --> N["Generate neighbours"]
N --> E["Evaluate values"]
E --> B["Choose candidate"]
B --> S
B --> G["Stop condition"]
style S fill:#E1F5FE
style N fill:#FFF9C4
style E fill:#EDE7F6
style B fill:#C8E6C9
style G fill:#C8E6C9
1. Path Optimisation vs State Optimisation ☆ #
In classical route search, the path is the solution. The agent must remember how it travelled from the start to the goal.