Bai, Yang; Fung, Wing K.; Zhu, Zhong Yi - In: Journal of Multivariate Analysis 100 (2009) 1, pp. 152-161
In this paper, we focus on single-index models for longitudinal data. We propose a procedure to estimate the single-index component and the unknown link function based on the combination of the penalized splines and quadratic inference functions. It is shown that the proposed estimation method...