5 papers
A Superfast Direct Solver for 2D Type-II Inverse Nonuniform Discrete Fourier Transform Based on Hierarchically Semiseparable Matrix
Yingzhou Li, Jingyu Liu
This paper proposes a direct inversion method for the 2D type-II nonuniform discrete Fourier transform~(NUDFT). The NUDFT matrix is factored as , where can be expr…
A Superfast Direct Solver for Type-III Inverse Nonuniform Discrete Fourier Transform
Yingzhou Li, Jingyu Liu
The nonuniform discrete Fourier transform (NUDFT) and its inverse are widely used in various fields of scientific computing. In this article, we propose a novel superfast direct in…
Products between block-encodings
Dekuan Dong, Yingzhou Li, Jungong Xue
Block-encoding is a standard framework for embedding matrices into unitary operators in quantum algorithms. Efficient implementation of products between block-encoded matrices is c…
A Model-Based Derivative-Free Optimization Algorithm for Partially Separable Problems
Yichuan Liu, Yingzhou Li
We propose UPOQA, a derivative-free optimization algorithm for partially separable unconstrained problems, leveraging quadratic interpolation and a structured trust-region framewor…
Hierarchical Tucker Low-Rank Matrices: Construction and Matrix-Vector Multiplication
Yingzhou Li, Jingyu Liu
In this paper, a hierarchical Tucker low-rank (HTLR) matrix is proposed to approximate non-oscillatory kernel functions in linear complexity. The HTLR matrix is based on the hierar…