Bachelor Thesis BCLR-2025-52

BibliographyTasteki, Ozan: Uncertainty-aware PCA for nonnormally distributed data.
University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Bachelor Thesis No. 52 (2025).
91 pages, english.
Abstract

Dimensionality reduction techniques are essential in modern data analysis to enable interpretable representations of high-dimensional data. Principal component analysis (PCA), a widespread approach, identifies directions of maximal variance and provides linear projections, but does not account for uncertainty in the data. The recently proposed uncertainty-aware PCA (UAPCA) extends PCA by modeling each data point not as a fixed vector but as a probability distribution, focusing on multivariate normal distributed data. However, many real-world datasets exhibit non-normal characteristics, rendering the Gaussian assumption insufficient. This thesis introduces a generalization termed non-normal uncertainty-aware PCA (NNUAPCA), that projects arbitrary probability density functions, such as Gaussian mixture models or histograms, into lower-dimensional spaces while preserving the uncertainty structure introduced by UAPCA. By analytically propagating non-Gaussian uncertainty through the DR pipeline, NNUAPCAovercomes the limitations ofUAPCA and makes our approach more applicable and accurate. The method is evaluated on synthetic and real-world datasets using qualitative visualizations and quantitative measures. Empirical results demonstrate that NNUAPCA produces low-dimensional embeddings that more faithfully preserve the uncertain structure of non-normally distributed data, while maintaining lower computational cost compared to other approaches.

Full text and
other links
Volltext
Department(s)University of Stuttgart, Institute of Visualisation and Interactive Systems, Visualisation and Interactive Systems
Superviser(s)Weiskopf, Prof. Daniel; Klötzl, Daniel; Evers, Dr. Marina; Hägele David
Entry dateNovember 7, 2025
New Report   New Article   New Monograph   Institute   Computer Science