QuatIca: Advanced Numerical Linear Algebra and Optimization for Quaternionic Matrices in Python

Fuente: arXiv
Saved in:
Bibliographic Details
Main Authors: Leplat, Valentin, Ahmadi-Asl, Salman, Pan, Junjun, Ouerdane, Henni, Ng, Michael
Format: Preprint
Published: 2026
Subjects:
Online Access:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866914420560494592
author Leplat, Valentin
Ahmadi-Asl, Salman
Pan, Junjun
Ouerdane, Henni
Ng, Michael
author_facet Leplat, Valentin
Ahmadi-Asl, Salman
Pan, Junjun
Ouerdane, Henni
Ng, Michael
contents Quaternion-valued representations provide a convenient way to model coupled multi-channel signals (e.g., RGB imagery, polarization data, vector fields, and multi-detector time series). Yet practical and numerically reliable software support remains far less mature than those based on the real/complex setting. Here, we present QuatIca, an open-source Python library for quaternion numerical linear algebra and optimization, designed for both research prototyping and reproducible experimentation. QuatIca provides core quaternion matrix operations and norms; dense decompositions and reductions (QR, LU, Q-SVD, eigendecomposition, Hessenberg/tridiagonal reduction, Cholesky decomposition, and Schur helpers); iterative solvers including quaternion GMRES (with preconditioning) and Newton-Schulz pseudoinverse schemes; and domain-focused routines for signal and image processing such as quaternion Tikhonov restoration. The library also includes OptiQ, which solves quaternion Hermitian semidefinite programs using log-det barrier Newton methods with $μ$-continuation. We highlight design choices that preserve quaternion structure, and we provide end-to-end demonstrations including quaternion image deblurring, Lorenz-attractor filtering, and quaternion image completion. QuatIca is distributed via PyPI and accompanied by open-source development on GitHub and continuously deployed documentation with runnable tutorials.
format Preprint
id arxiv_https___arxiv_org_abs_2603_24074
institution arXiv
publishDate 2026
record_format arxiv
spellingShingle QuatIca: Advanced Numerical Linear Algebra and Optimization for Quaternionic Matrices in Python
Leplat, Valentin
Ahmadi-Asl, Salman
Pan, Junjun
Ouerdane, Henni
Ng, Michael
Numerical Analysis
Quaternion-valued representations provide a convenient way to model coupled multi-channel signals (e.g., RGB imagery, polarization data, vector fields, and multi-detector time series). Yet practical and numerically reliable software support remains far less mature than those based on the real/complex setting. Here, we present QuatIca, an open-source Python library for quaternion numerical linear algebra and optimization, designed for both research prototyping and reproducible experimentation. QuatIca provides core quaternion matrix operations and norms; dense decompositions and reductions (QR, LU, Q-SVD, eigendecomposition, Hessenberg/tridiagonal reduction, Cholesky decomposition, and Schur helpers); iterative solvers including quaternion GMRES (with preconditioning) and Newton-Schulz pseudoinverse schemes; and domain-focused routines for signal and image processing such as quaternion Tikhonov restoration. The library also includes OptiQ, which solves quaternion Hermitian semidefinite programs using log-det barrier Newton methods with $μ$-continuation. We highlight design choices that preserve quaternion structure, and we provide end-to-end demonstrations including quaternion image deblurring, Lorenz-attractor filtering, and quaternion image completion. QuatIca is distributed via PyPI and accompanied by open-source development on GitHub and continuously deployed documentation with runnable tutorials.
title QuatIca: Advanced Numerical Linear Algebra and Optimization for Quaternionic Matrices in Python
topic Numerical Analysis
url https://arxiv.org/abs/2603.24074