Tags / science

• Quiver Geometry discrete geometry via graph theory Quiver geometry is an experiment in defining a kind of discrete geometry purely in terms of directed graphs with a particular structure of edge labels on them. I began thinking about this project in late 2020 when thinking about the abstract geometry induced by computational rewriting systems, having found nothing in the existing literature that seemed like a good “port” of the methods and theories of classical differential geometry to the setting of discrete geometry. I started to …

• MCTS in Swift AlphaZero and MCTS implementation for OpenSpiel This project is a work-in-progress fork of the OpenSpiel library. It adds an MCTS implementation that will form the basis of a simple AlphaZero trainer. The design leverages some of the powerful type system abilities of Swift to achieve a maximally composable design, which allows the underlying tree-building implementation to be shared between several algorithms (various variants of MCTS, as well as Alpha-Beta search), which additionally makes them very clear. The fundamental Swift constructs …

• Spieeltjie experiment with multi-agent RL on zero-sum differentiable games Spieeltjie is a single-file package for doing simple experiments with multi-agent reinforcement learning on symmetric zero-sum games. For more information see “Open-ended learning in Symmetric Zero-Sum Games” and “A Unified Game-Theoretic Approach to Multiagent Reinforcement Learning”. The name “spieeltjie” comes from the Afrikaans word for “tournament”. […] This first set of images shows trajectories when starting from a set of random …
• Biologically Plausible Backprop feedback alignment & activity perturbation in PyTorch SOAP (Second Order Activity Perturbation) is a package for experimenting with a computational neuroscience phenomenon called feedback alignment in PyTorch. It formed my project for the 3-week IBRO-Simons Computational Neuroscience Summer School in 2019. It relates to an important challenge in reconciling how learning works in artificial neural networks with what we know about how real neurons behave, a topic called biologically plausible back-propogation. […] When a neuron fires, its axon …

• Facebook Data Analysis analysis and visualization for popular blog by Stephen Wolfram For this project, I helped Stephen Wolfram analyze a dataset of Facebook profiles we collected from volunteers who engaged with a previous project I worked on. We looked at the influence of the friendship paradox, correlations between various demographic variables, performed topic modeling on people’s facebook posts, and did cluster analysis on their friend graphs. The friendship paradox summarizes that, on average, your friends have more friends than you do, because popular people are …

• Spatial Game Theory package for experiments in evolutionary spatial game theory SGT is a Mathematica package to unlock effortless explorations in evolutionary spatial game theory. Using SGT, you can setup, conduct and visualize experiments using a small number of functions and symbolic expressions to specify the initial distribution of agents, the topology of the grid, the strategies the agents employ, the payoff structure of the games they play, the rules used to update the agents and apply natural selection, whether and how mutation occurs, whether agents have access to …

• Floatworld evolutionary sim of RNN-controlled agents on a gridworld floatworld is an C++ library and associated GUI that serves as a laboratory for a multi-agent RNN-based simulation in which agents compete for space and energy on a two-dimensional grid. I wrote floatworld, along with a short paper about it, during my undergraduate degree. Each agent is controlled by a recurrent neural network and harvests energy in order to reproduce. Time and space are discretized. Agents obtain a variety of data from their environments that is fed to their neural network …

• RLC Diagnostics program to use sound card to measure RLC circuit resonance I completed this project while studying my final year of high school. I was in the process of building and tuning an electromagnetic coilgun, and as part of that effort I needed to accurately measure the inductance of my prototype coils. Unfortunately, I couldn’t afford the expensive, professional equipment that could make such measurements. Fortunately, I read about the techniques that this equipment actually used, and I realized I could use my computer’s sound card to do much the …

• Using Python to Improve My Coilgun Jul 17