activity
20232026
most citedGeometric persistence and distributional trends in worldwide terrorism

15 citations · 15 across the 5 of their papers we have counts for

collaborators

6 papers

stat.CO2026

From Continuous Dynamics to Practical Gradient-Based Samplers

James Chok

Gradient-based Markov chain Monte Carlo methods are often introduced as a catalog of algorithms: Hamiltonian Monte Carlo (HMC), the Metropolis-adjusted Langevin algorithm (MALA), t…

stat.CO2025

Constrained Dikin-Langevin diffusion for polyhedra

James Chok, Domenic Petzinna

We propose a reflection-free Langevin framework for sampling and optimization on compact polyhedra. The method is based on the inverse Hessian of the logarithmic barrier, which def…

stat.CO2025

Divide, Interact, Sample: The Two-System Paradigm

James Chok, Myung Won Lee, Daniel Paulin +1

Mean-field, ensemble-chain, and adaptive samplers have historically been viewed as distinct approaches to Monte Carlo sampling. In this paper, we present a unifying {two-system} fr…

math.NA2023

Rational function approximation with normalized positive denominators

James Chok, Geoffrey M. Vasil

Recent years have witnessed the introduction and development of extremely fast rational function algorithms. Many ideas in this realm arose from polynomial-based linear-algebraic a…

math.OC2023

Convex optimization over a probability simplex

James Chok, Geoffrey M. Vasil

We propose a new iteration scheme, the Cauchy-Simplex, to optimize convex problems over the probability simplex . Spe…

physics.soc-ph2023★ 15 cited

Geometric persistence and distributional trends in worldwide terrorism

Nick James, Max Menzies, James Chok +2

This paper introduces new methods for studying the prevalence of terrorism around the world and over time. Our analysis treats spatial prevalence of terrorism, the changing profile…