A Powerful Global Test Statistic for Functional Statistical Inference

  • Jingwen Zhang University of North Carolina at Chapel Hill
  • Joseph Ibrahim University of North Carolina at Chapel Hill
  • Tengfei Li MD Anderson Cancer Center
  • Hongtu Zhu University of North Carolina at Chapel Hill

Abstract

We consider the problem of performing an association test between functional data and scalar variables in a varying coefficient model setting. We propose a functional projection regression model and an associated global test statistic to aggregate relatively weak signals across the domain of functional data, while reducing the dimension. An optimal functional projection direction is selected to maximize signal-to-noise ratio with ridge penalty. Theoretically, we systematically study the asymptotic distribution of the global test statistic and provide a strategy to adaptively select the optimal tuning parameter. We use simulations to show that the proposed test outperforms all existing state-of-the-art methods in functional statistical inference. Finally, we apply the proposed testing method to the genome-wide association analysis of imaging genetic data in UK Biobank dataset.

Published
2019-07-17
Section
AAAI Technical Track: Machine Learning