Experienced Optimization with Reusable Directional Model for Hyper-Parameter Search

Experienced Optimization with Reusable Directional Model for Hyper-Parameter Search

Yi-Qi Hu, Yang Yu, Zhi-Hua Zhou

Proceedings of the Twenty-Seventh International Joint Conference on Artificial Intelligence
Main track. Pages 2276-2282. https://doi.org/10.24963/ijcai.2018/315

Hyper-parameter selection is a crucial yet difficult issue in machine learning. For this problem, derivative-free optimization has being playing an irreplaceable role. However, derivative-free optimization commonly requires a lot of hyper-parameter samples, while each sample could have a high cost for hyper-parameter selection due to the costly evaluation of a learning model. To tackle this issue, in this paper, we propose an experienced optimization approach, i.e., learning how to optimize better from a set of historical optimization processes. From the historical optimization processes on previous datasets, a directional model is trained to predict the direction of the next good hyper-parameter. The directional model is then reused to guide the optimization in learning new datasets. We implement this mechanism within a state-of-the-art derivative-free optimization method SRacos, and conduct experiments on learning the hyper-parameters of heterogeneous ensembles and neural network architectures. Experimental results verify that the proposed approach can significantly improve the learning accuracy within a limited hyper-parameter sample budget.
Keywords:
Machine Learning: Machine Learning
Machine Learning: Transfer, Adaptation, Multi-task Learning