Additive Tree-Structured Covariance Function for Conditional Parameter Spaces in Bayesian Optimization

Abstract

Bayesian optimization (BO) is a sample-efficient global optimization algorithm for black-box functions which are expensive to evaluate. Existing literature on model based optimization in conditional parameter spaces are usually built on trees. In this work, we generalize the additive assumption to tree-structured functions and propose an additive tree-structured covariance function, showing improved sample-efficiency, wider applicability and greater flexibility. Furthermore, by incorporating the structure information of parameter spaces and the additive assumption in the BO loop, we develop a parallel algorithm to optimize the acquisition function and this optimization can be performed in a low dimensional space. We demonstrate our method on an optimization benchmark function, as well as on a neural network model compression problem, and experimental results show our approach significantly outperforms the current state of the art for conditional parameter optimization including SMAC, TPE and Jenatton et al. (2017).

arXiv commentAISTATS2020. Code link: https://github.com/maxc01/addtree

References in corpus (6)

• A Tutorial on Bayesian Optimization of Expensive Cost Functions, with Application to Active User Modeling and Hierarchical Reinforcement Learning
• Hyperband: A Novel Bandit-Based Approach to Hyperparameter Optimization
• A Tutorial on Bayesian Optimization
• Additive Gaussian Processes
• High-Dimensional Bayesian Optimization via Additive Models with Overlapping Groups
• On Local Optimizers of Acquisition Functions in Bayesian Optimization

Cited by in corpus (1)

• Additive Tree-Structured Conditional Parameter Spaces in Bayesian Optimization: A Novel Covariance Function and a Fast Implementation