# Concept Collection A set of small, independent projects: interactive demos, teaching material, and research code. Most run directly in the browser with nothing to install. The recurring themes are running MATLAB-syntax code in the browser with [numbl](https://numbl.org), tooling for scientific data, and visualizing mathematical structure. Each project below links to its repository, and to a live page where there is one. ## Run-in-browser MATLAB (numbl) MATLAB-syntax projects that run in the browser via [numbl](https://numbl.org). - **[numbl-quantum-optics](https://github.com/concept-collection/numbl-quantum-optics)** ([live](https://concept-collection.github.io/numbl-quantum-optics/)). Runnable scripts accompanying the article "Quantum optics in MATLAB" ([arXiv:2309.14354](https://arxiv.org/abs/2309.14354)), covering quantum states, operators, and dynamics. - **[numbl-open-quantum-systems](https://github.com/concept-collection/numbl-open-quantum-systems)** ([live](https://concept-collection.github.io/numbl-open-quantum-systems/)). Code from "Coding closed and open quantum systems in MATLAB" ([arXiv:1911.04906](https://arxiv.org/abs/1911.04906)), including Ising dynamics, cavity-QED phase transitions, and Lindblad and non-Markovian evolution. - **[numbl-distmesh](https://github.com/concept-collection/numbl-distmesh)** ([live](https://concept-collection.github.io/numbl-distmesh/)). Every example from Persson and Strang's [DistMesh](https://github.com/popersson/DistMesh), meshing 2-D regions and surfaces from signed distance functions. - **[numbl-surfacefun-intro](https://github.com/concept-collection/numbl-surfacefun-intro)** ([live](https://concept-collection.github.io/numbl-surfacefun-intro/)). An introduction to [surfacefun](https://github.com/danfortunato/surfacefun), which computes with functions on surfaces and solves PDEs on them to high order. - **[surfacefun-interactive](https://github.com/concept-collection/surfacefun-interactive)** ([live](https://concept-collection.github.io/surfacefun-interactive/)). surfacefun demos with live sliders, where React and three.js drive a numbl script. Refine a cubed-sphere mesh or scale a tangent vector field and watch it update. - **[numbl-chunkie](https://github.com/concept-collection/numbl-chunkie)** ([live](https://concept-collection.github.io/numbl-chunkie/)). Examples for [chunkie](https://github.com/fastalgorithms/chunkie): building chunker geometries in 2-D and solving Laplace, Helmholtz, and Stokes boundary integral equations. - **[numbl-image-filter](https://github.com/concept-collection/numbl-image-filter)** ([live](https://concept-collection.github.io/numbl-image-filter/)). Upload an image, write a MATLAB-syntax filter, and run it on the image in the browser. - **[numbl-figure-viewer](https://github.com/concept-collection/numbl-figure-viewer)** ([live](https://concept-collection.github.io/numbl-figure-viewer/)). Open and explore a figure exported from numbl, including its underlying data. - **[numbl-project-example](https://github.com/concept-collection/numbl-project-example)** ([live](https://concept-collection.github.io/numbl-project-example/)). A minimal numbl project deployed to GitHub Pages, meant as a starting template. - **[numbl-embed-example](https://github.com/concept-collection/numbl-embed-example)** ([live](https://concept-collection.github.io/numbl-embed-example/)). Shows how to embed editable, runnable numbl scripts inside Markdown rendered on GitHub Pages. ## Data compression - **[benchcompress](https://github.com/concept-collection/benchcompress)** ([results](https://concept-collection.github.io/benchcompress/), [paper (WIP)](https://concept-collection.github.io/benchcompress/paper)). A benchmarking framework that measures compression ratio and encode/decode throughput for compression algorithms on scientific data arrays. - **[ephys_compression_tests](https://github.com/concept-collection/ephys_compression_tests)** ([results](https://concept-collection.github.io/ephys_compression_tests/)). Compression benchmarks for electrophysiology recordings. - **[ans-visualizer](https://github.com/concept-collection/ans-visualizer)** ([live](https://concept-collection.github.io/ans-visualizer/)). A step-by-step visualizer for the Asymmetric Numeral Systems (ANS) entropy-coding algorithm ([Duda et al., 2015](https://ieeexplore.ieee.org/abstract/document/7170048)). ## Neurophysiology data and remote access - **[remote-hdf5-lazy-read](https://github.com/concept-collection/remote-hdf5-lazy-read)** ([live](https://concept-collection.github.io/remote-hdf5-lazy-read/)). Shows how [neurosift](https://neurosift.app/) browses large remote [NWB](https://www.nwb.org/)/HDF5 files in the browser using HTTP range requests, with no full download and no backend. - **[dandiset_000986](https://github.com/concept-collection/dandiset_000986)** ([visualizations](https://concept-collection.github.io/dandiset_000986/)). Reproducible figures and visualizations for [DANDI Dandiset 000986](https://dandiarchive.org/dandiset/000986), a set of mouse auditory cortex recordings. ## Mathematical visualizers - **[finite-field-visualizer](https://github.com/concept-collection/finite-field-visualizer)** ([live](https://concept-collection.github.io/finite-field-visualizer/)). Color-coded multiplication tables over finite (prime) fields. Step through the primes to watch the structure change. - **[gcd-visualizer](https://github.com/concept-collection/gcd-visualizer)** ([live](https://concept-collection.github.io/gcd-visualizer/)). A heatmap of the greatest common divisor of every pair (i, j), laid out as a color-coded table. ## Computational geometry - **[qhull-wasm-demo](https://github.com/concept-collection/qhull-wasm-demo)** ([live](https://concept-collection.github.io/qhull-wasm-demo/)). Demos and benchmarks for [qhull-wasm](https://github.com/magland/qhull-wasm), which compiles [Qhull](http://www.qhull.org) to WebAssembly. Includes 2-D Delaunay triangulation, 3-D convex hull, and a Delaunay benchmark with matching scripts for MATLAB, Octave, and numbl.