John Parker, PhD

Computational physicist turned Software Engineer, exploring topics in physics, high performance computing, computer graphics, and agentic AI

Try it cargo install loom-tui

Loom

TUI control center for managing git worktrees and agentic workflows, supporting Claude Code, GitHub, and Linear

Rust

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Try it uvx -p 3.13 miepy

MiePy

Solve Maxwell's equations for a cluster of particles using the generalized multiparticle Mie theory (GMMT)

Python C++

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Try it uvx fplanck

FPlanck

Numerically solve the Fokker-Planck partial differential equation in N dimensions using a matrix numerical method

Python

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Try it uvx stoked

Stoked

Solve the Stokesian dynamics equations for N interacting particles, a generalization of Brownian dynamics that includes hydrodynamic coupling interactions

Python

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Recent Gallery

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Granular Hopper

Spherical granular particles falling through a glass hopper

Ray tracing Granular materials

Asteroid Belt Planet

A planet with an asteroid belt and an orbiting satellite

Ray tracing

Optical Matter Array

An assembly of optically bound metal nanoparticles in a tightly focused laser beam.

Electromagnetism

Flow of Electromagnetic Energy Around a Nanoscale Optical Matter Machine

Streamlines of the Poynting vector around a hexagonal nanoparticle array composed of seven metal nanoparticles

Electromagnetism

Software Engineering with Parallel Coding Agents

January 29, 2026

How I built a 16k-line Rust TUI in one week without writing or reading any code, using Claude Code and parallel agents to manage Git worktrees.

Agentic AI

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Real-time visualization of a large number of circles using OpenGL

November 7, 2020

When using Matplotlib, animations of a large number of circles becomes slow. Using OpenGL, over a million circles can be animated in realtime.

Graphics Performance

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Measuring the overlap of Delaunay tessellations

September 25, 2020

Given two or more Delaunay tessellations, you may be interested in measuring how much they overlap with one another

Data analysis

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FFT performance using NumPy, PyFFTW, and cuFFT

October 14, 2020

Compare the performance of different FFT implementations, using Python

Performance

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Emre Sevgen, Joshua Moller, Adrian Lange, John Parker, Sean Quigley, Jeff Mayer, Poonam Srivastava, Sitaram Gayatri, David Hosfield, Maria Korshunova, Micha Livne, Michelle Gill, Rama Ranganathan, Anthony B. Costa, Andrew L. Ferguson

PNAS (2025)

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DOI: 10.1073/pnas.2408737122