EquiTabPFN: A Target-Permutation Equivariant Prior Fitted Networks

Fuente: arXiv
Saved in:
Bibliographic Details
Main Authors: Arbel, Michael, Salinas, David, Hutter, Frank
Format: Preprint
Published: 2025
Subjects:
Online Access:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866908750371094528
author Arbel, Michael
Salinas, David
Hutter, Frank
author_facet Arbel, Michael
Salinas, David
Hutter, Frank
contents Recent foundational models for tabular data, such as TabPFN, excel at adapting to new tasks via in-context learning, but remain constrained to a fixed, pre-defined number of target dimensions-often necessitating costly ensembling strategies. We trace this constraint to a deeper architectural shortcoming: these models lack target equivariance, so that permuting target dimension orderings alters their predictions. This deficiency gives rise to an irreducible "equivariance gap", an error term that introduces instability in predictions. We eliminate this gap by designing a fully target-equivariant architecture-ensuring permutation invariance via equivariant encoders, decoders, and a bi-attention mechanism. Empirical evaluation on standard classification benchmarks shows that, on datasets with more classes than those seen during pre-training, our model matches or surpasses existing methods while incurring lower computational overhead.
format Preprint
id arxiv_https___arxiv_org_abs_2502_06684
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle EquiTabPFN: A Target-Permutation Equivariant Prior Fitted Networks
Arbel, Michael
Salinas, David
Hutter, Frank
Machine Learning
Artificial Intelligence
Recent foundational models for tabular data, such as TabPFN, excel at adapting to new tasks via in-context learning, but remain constrained to a fixed, pre-defined number of target dimensions-often necessitating costly ensembling strategies. We trace this constraint to a deeper architectural shortcoming: these models lack target equivariance, so that permuting target dimension orderings alters their predictions. This deficiency gives rise to an irreducible "equivariance gap", an error term that introduces instability in predictions. We eliminate this gap by designing a fully target-equivariant architecture-ensuring permutation invariance via equivariant encoders, decoders, and a bi-attention mechanism. Empirical evaluation on standard classification benchmarks shows that, on datasets with more classes than those seen during pre-training, our model matches or surpasses existing methods while incurring lower computational overhead.
title EquiTabPFN: A Target-Permutation Equivariant Prior Fitted Networks
topic Machine Learning
Artificial Intelligence
url https://arxiv.org/abs/2502.06684