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Main Authors: Hahn, Georg, Banerjee, Moulinath, Sen, Bodhisattva
Format: Preprint
Published: 2025
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Online Access:https://arxiv.org/abs/2503.06303
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author Hahn, Georg
Banerjee, Moulinath
Sen, Bodhisattva
author_facet Hahn, Georg
Banerjee, Moulinath
Sen, Bodhisattva
contents The estimation of regression parameters in one dimensional broken stick models is a research area of statistics with an extensive literature. We are interested in extending such models by aiming to recover two or more intersecting (hyper)planes in multiple dimensions. In contrast to approaches aiming to recover a given number of piecewise linear components using either a grid search or local smoothing around the change points, we show how to use Nesterov smoothing to obtain a smooth and everywhere differentiable approximation to a piecewise linear regression model with a uniform error bound. The parameters of the smoothed approximation are then efficiently found by minimizing a least squares objective function using a quasi-Newton algorithm. Our main contribution is threefold: We show that the estimates of the Nesterov smoothed approximation of the broken plane model are also $\sqrt{n}$ consistent and asymptotically normal, where $n$ is the number of data points on the two planes. Moreover, we show that as the degree of smoothing goes to zero, the smoothed estimates converge to the unsmoothed estimates and present an algorithm to perform parameter estimation. We conclude by presenting simulation results on simulated data together with some guidance on suitable parameter choices for practical applications.
format Preprint
id arxiv_https___arxiv_org_abs_2503_06303
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Parameter Estimation and Inference in a Continuous Piecewise Linear Regression Model
Hahn, Georg
Banerjee, Moulinath
Sen, Bodhisattva
Methodology
The estimation of regression parameters in one dimensional broken stick models is a research area of statistics with an extensive literature. We are interested in extending such models by aiming to recover two or more intersecting (hyper)planes in multiple dimensions. In contrast to approaches aiming to recover a given number of piecewise linear components using either a grid search or local smoothing around the change points, we show how to use Nesterov smoothing to obtain a smooth and everywhere differentiable approximation to a piecewise linear regression model with a uniform error bound. The parameters of the smoothed approximation are then efficiently found by minimizing a least squares objective function using a quasi-Newton algorithm. Our main contribution is threefold: We show that the estimates of the Nesterov smoothed approximation of the broken plane model are also $\sqrt{n}$ consistent and asymptotically normal, where $n$ is the number of data points on the two planes. Moreover, we show that as the degree of smoothing goes to zero, the smoothed estimates converge to the unsmoothed estimates and present an algorithm to perform parameter estimation. We conclude by presenting simulation results on simulated data together with some guidance on suitable parameter choices for practical applications.
title Parameter Estimation and Inference in a Continuous Piecewise Linear Regression Model
topic Methodology
url https://arxiv.org/abs/2503.06303