Unreduced Persistence Diagrams for Topological Machine Learning

· Source: stat.ML updates on arXiv.org · Field: Technology & Digital — Artificial Intelligence & Machine Learning, Data Science & Analytics, Mathematics & Computational Sciences · Depth: Expert, extended

Summary

Parker B. Edwards introduces methods to generate topological feature vectors from unreduced boundary matrices, challenging the conventional reliance on fully-reduced persistence diagrams (FR PDs) in topological machine learning (TML) pipelines. The study explores three types of unreduced PDs: non-negative betas (NNB), apparent pair (AP), and naive low-ones (L1). Experiments across synthetic shape classification, Fashion MNIST image classification, and brain artery tree regression tasks demonstrate that models trained on unreduced PDs can perform comparably to, and in some cases, outperform those using FR PDs. Notably, L1 diagrams clearly outperformed FR diagrams in Fashion MNIST classification, achieving 78% accuracy versus 66% for simplified models, and 91% versus 84% for specific classes. This suggests that utilizing unreduced boundary matrix information could offer computational cost savings by avoiding the demanding full reduction step, despite potentially longer vectorization times for larger unreduced diagrams.

Key takeaway

For Machine Learning Engineers optimizing topological data analysis pipelines, you should investigate integrating unreduced persistence diagrams. Specifically, consider L1 diagrams, which demonstrated comparable or superior performance to fully-reduced diagrams in tasks like Fashion MNIST classification. This approach can potentially reduce the significant computational burden of boundary matrix reduction, allowing for more efficient model training. Benchmark the vectorization costs of larger unreduced diagrams against the savings from skipping reduction.

Key insights

Unreduced persistence diagrams can match or exceed fully-reduced PD performance in topological machine learning, potentially saving computation.

Principles

Method

The study compared four diagram constructions (FR, NNB, AP, L1) using a PH/ML pipeline template, vectorizing PDs with persistence images or Adcock-Carlsson coordinates, and training random forest classifiers/regressors.

In practice

Topics

Best for: AI Scientist, Machine Learning Engineer, Research Scientist

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Editorial summary, takeaway, and curation by AIssential. Original article published by stat.ML updates on arXiv.org.