no code implementations • 13 Apr 2020 • Gregory Naitzat, Andrey Zhitnikov, Lek-Heng Lim
We study how the topology of a data set $M = M_a \cup M_b \subseteq \mathbb{R}^d$, representing two classes $a$ and $b$ in a binary classification problem, changes as it passes through the layers of a well-trained neural network, i. e., with perfect accuracy on training set and near-zero generalization error ($\approx 0. 01\%$).
1 code implementation • ICML 2018 • Liwen Zhang, Gregory Naitzat, Lek-Heng Lim
Among other things, we deduce that feedforward ReLU neural networks with one hidden layer can be characterized by zonotopes, which serve as building blocks for deeper networks; we relate decision boundaries of such neural networks to tropical hypersurfaces, a major object of study in tropical geometry; and we prove that linear regions of such neural networks correspond to vertices of polytopes associated with tropical rational functions.