Golden Ratio-Based Sufficient Dimension Reduction
Wenjing Yang, Yuhong Yang
TL;DR
This paper introduces GRNN-SDR, a neural-network–based sufficient dimension reduction method that uses a golden-ratio–driven search to identify the structural dimension while accurately estimating the central space $\boldsymbol{S}_{Y|X}$. Grounded in Barron-class function approximation, the method provides theoretical guarantees: an $O(N)$ training complexity for a fixed network and risk bounds that balance approximation and estimation error. The approach accommodates practical dimension reduction via $\delta_N$-approximation and demonstrates strong empirical performance across diverse simulations, often outperforming traditional SDR methods in both accuracy and efficiency. The framework extends naturally to deeper architectures, enabling scalable SDR in high-dimensional settings encountered in modern data applications, with robust performance even when the true dimension is unknown.
Abstract
Many machine learning applications deal with high dimensional data. To make computations feasible and learning more efficient, it is often desirable to reduce the dimensionality of the input variables by finding linear combinations of the predictors that can retain as much original information as possible in the relationship between the response and the original predictors. We propose a neural network based sufficient dimension reduction method that not only identifies the structural dimension effectively, but also estimates the central space well. It takes advantages of approximation capabilities of neural networks for functions in Barron classes and leads to reduced computation cost compared to other dimension reduction methods in the literature. Additionally, the framework can be extended to fit practical dimension reduction, making the methodology more applicable in practical settings.
