Saved in:
Bibliographic Details
Main Authors: Wei, Yi, Qi, Xuan, Shen, Furao
Format: Preprint
Published: 2026
Subjects:
Online Access:https://arxiv.org/abs/2605.06300
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866915997296885760
author Wei, Yi
Qi, Xuan
Shen, Furao
author_facet Wei, Yi
Qi, Xuan
Shen, Furao
contents Deep networks with continuous piecewise affine activations induce polyhedral partitions of the input space, making the number of realized affine regions a natural measure of expressive capacity and a key determinant of how well the model can approximate nonlinear target functions. In practice, standard training realizes far fewer region refinements in data-visited neighborhoods than the architecture could in principle support, while existing region-count theory is primarily architectural and offers little guidance on how optimization shapes the realized partition near the data. Our theory provides a sufficient condition under which bringing neuron switching surfaces sufficiently close to data points ensures their intersection with local neighborhoods, which in turn implies a strict increase in the local affine-region count, yielding a principled training-time handle for seeding data-relevant partitions early in optimization. Guided by these results, we propose a plug-and-play region-seeding regularizer that encourages early partitioning while allowing task-driven refinement to dominate later in training. Experiments show that the regularizer increases the number of realized affine regions via exact enumeration and improves overall performance on toy datasets, while also improving early-stage accuracy and achieving comparable (or slightly improved) final accuracy on ImageNet-1k for classical models.
format Preprint
id arxiv_https___arxiv_org_abs_2605_06300
institution arXiv
publishDate 2026
record_format arxiv
spellingShingle Region Seeding via Pre-Activation Regularization: A Geometric View of Piecewise Affine Neural Networks
Wei, Yi
Qi, Xuan
Shen, Furao
Machine Learning
Deep networks with continuous piecewise affine activations induce polyhedral partitions of the input space, making the number of realized affine regions a natural measure of expressive capacity and a key determinant of how well the model can approximate nonlinear target functions. In practice, standard training realizes far fewer region refinements in data-visited neighborhoods than the architecture could in principle support, while existing region-count theory is primarily architectural and offers little guidance on how optimization shapes the realized partition near the data. Our theory provides a sufficient condition under which bringing neuron switching surfaces sufficiently close to data points ensures their intersection with local neighborhoods, which in turn implies a strict increase in the local affine-region count, yielding a principled training-time handle for seeding data-relevant partitions early in optimization. Guided by these results, we propose a plug-and-play region-seeding regularizer that encourages early partitioning while allowing task-driven refinement to dominate later in training. Experiments show that the regularizer increases the number of realized affine regions via exact enumeration and improves overall performance on toy datasets, while also improving early-stage accuracy and achieving comparable (or slightly improved) final accuracy on ImageNet-1k for classical models.
title Region Seeding via Pre-Activation Regularization: A Geometric View of Piecewise Affine Neural Networks
topic Machine Learning
url https://arxiv.org/abs/2605.06300