1# Concept Collection
3A set of small, independent projects: interactive demos, teaching material, and
4research code. Most run directly in the browser with nothing to install, and
5many are written in MATLAB syntax and run there via [numbl](https://numbl.org).
7Projects are grouped below by **application area** — physics, numerical methods,
8data compression, neurophysiology, visual math, and more — rather than by the
9technology behind them. Each links to its repository, and to a live page where
10there is one.
12## Physics & quantum systems
14- **[numbl-quantum-optics](https://github.com/concept-collection/numbl-quantum-optics)**
15 ([live](https://concept-collection.github.io/numbl-quantum-optics/)).
16 Runnable scripts accompanying the article "Quantum optics in MATLAB"
17 ([arXiv:2309.14354](https://arxiv.org/abs/2309.14354)), covering quantum
18 states, operators, and dynamics.
19- **[numbl-open-quantum-systems](https://github.com/concept-collection/numbl-open-quantum-systems)**
20 ([live](https://concept-collection.github.io/numbl-open-quantum-systems/)).
21 Code from "Coding closed and open quantum systems in MATLAB"
22 ([arXiv:1911.04906](https://arxiv.org/abs/1911.04906)), including Ising
23 dynamics, cavity-QED phase transitions, and Lindblad and non-Markovian
24 evolution.
26## Geometry, meshing & PDE solvers
28- **[numbl-distmesh](https://github.com/concept-collection/numbl-distmesh)**
29 ([live](https://concept-collection.github.io/numbl-distmesh/)).
30 Every example from Persson and Strang's
31 [DistMesh](https://github.com/popersson/DistMesh), meshing 2-D regions and
32 surfaces from signed distance functions.
33- **[numbl-surfacefun-intro](https://github.com/concept-collection/numbl-surfacefun-intro)**
34 ([live](https://concept-collection.github.io/numbl-surfacefun-intro/)).
35 An introduction to [surfacefun](https://github.com/danfortunato/surfacefun),
36 which computes with functions on surfaces and solves PDEs on them to high
37 order.
38- **[surfacefun-interactive](https://github.com/concept-collection/surfacefun-interactive)**
39 ([live](https://concept-collection.github.io/surfacefun-interactive/)).
40 surfacefun demos with live sliders, where React and three.js drive a numbl
41 script. Refine a cubed-sphere mesh or scale a tangent vector field and watch
42 it update.
43- **[numbl-chunkie](https://github.com/concept-collection/numbl-chunkie)**
44 ([live](https://concept-collection.github.io/numbl-chunkie/)).
45 Examples for [chunkie](https://github.com/fastalgorithms/chunkie): building
46 chunker geometries in 2-D and solving Laplace, Helmholtz, and Stokes boundary
47 integral equations.
48- **[qhull-wasm-demo](https://github.com/concept-collection/qhull-wasm-demo)**
49 ([live](https://concept-collection.github.io/qhull-wasm-demo/)).
50 Demos and benchmarks for [qhull-wasm](https://github.com/magland/qhull-wasm),
51 which compiles [Qhull](http://www.qhull.org) to WebAssembly. Includes 2-D
52 Delaunay triangulation, 3-D convex hull, and a Delaunay benchmark with
53 matching scripts for MATLAB, Octave, and numbl.
55## Monte Carlo & sampling
57- **[hitandrun-interactive](https://github.com/concept-collection/hitandrun-interactive)**
58 ([live](https://concept-collection.github.io/hitandrun-interactive/#figure/sampler)).
59 Hit-and-run MCMC sampling of a 2-D convex region, with React driving a numbl
60 script. Resample, make new regions, or play a step-by-step movie of the
61 algorithm.
62- **[hitandrun-commonview](https://github.com/concept-collection/hitandrun-commonview)**
63 ([live](https://concept-collection.github.io/hitandrun-commonview/)).
64 The hit-and-run figure with a single live view shared by all visitors over a
65 WebRTC mesh; one peer runs the sampler via numbl and broadcasts to the rest.
66- **[walnuts-interactive](https://github.com/concept-collection/walnuts-interactive)**
67 ([live](https://concept-collection.github.io/walnuts-interactive/#figure/sampler)).
68 WALNUTS (the within-orbit adaptive leapfrog No-U-Turn Sampler) drawing from a
69 2-D banana target, with React driving a numbl script. Tune the leapfrog step
70 and error tolerance, or play a step-by-step movie of the orbit-building.
72## Peer-to-peer shared state
74- **[commonview](https://github.com/concept-collection/commonview)**
75 ([live](https://concept-collection.github.io/commonview/)).
76 A minimal peer-to-peer page where every visitor shares one state (a counter):
77 nostr discovery, a WebRTC mesh, and a central-peer authority. The basis for
78 hitandrun-commonview.
80## Scientific data compression
82- **[benchcompress](https://github.com/concept-collection/benchcompress)**
83 ([results](https://concept-collection.github.io/benchcompress/),
84 [paper (WIP)](https://concept-collection.github.io/benchcompress/paper)).
85 A benchmarking framework that measures compression ratio and encode/decode
86 throughput for compression algorithms on scientific data arrays.
87- **[ephys_compression_tests](https://github.com/concept-collection/ephys_compression_tests)**
88 ([results](https://concept-collection.github.io/ephys_compression_tests/)).
89 Compression benchmarks for electrophysiology recordings.
90- **[ans-visualizer](https://github.com/concept-collection/ans-visualizer)**
91 ([live](https://concept-collection.github.io/ans-visualizer/)).
92 A step-by-step visualizer for the Asymmetric Numeral Systems (ANS)
93 entropy-coding algorithm ([Duda et al., 2015](https://ieeexplore.ieee.org/abstract/document/7170048)).
95## Neurophysiology data & remote access
97- **[remote-hdf5-lazy-read](https://github.com/concept-collection/remote-hdf5-lazy-read)**
98 ([live](https://concept-collection.github.io/remote-hdf5-lazy-read/)).
99 Shows how [neurosift](https://neurosift.app/) browses large remote
100 [NWB](https://www.nwb.org/)/HDF5 files in the browser using HTTP range
101 requests, with no full download and no backend.
102- **[dandiset_000986](https://github.com/concept-collection/dandiset_000986)**
103 ([visualizations](https://concept-collection.github.io/dandiset_000986/)).
104 Reproducible figures and visualizations for
105 [DANDI Dandiset 000986](https://dandiarchive.org/dandiset/000986), a set of
106 mouse auditory cortex recordings.
108## Number theory & visual math
110- **[finite-field-visualizer](https://github.com/concept-collection/finite-field-visualizer)**
111 ([live](https://concept-collection.github.io/finite-field-visualizer/)).
112 Color-coded multiplication tables over finite (prime) fields. Step through the
113 primes to watch the structure change.
114- **[gcd-visualizer](https://github.com/concept-collection/gcd-visualizer)**
115 ([live](https://concept-collection.github.io/gcd-visualizer/)).
116 A heatmap of the greatest common divisor of every pair (i, j), laid out as a
117 color-coded table.
119## Image processing
121- **[numbl-image-filter](https://github.com/concept-collection/numbl-image-filter)**
122 ([live](https://concept-collection.github.io/numbl-image-filter/)).
123 Upload an image, write a MATLAB-syntax filter, and run it on the image in the
124 browser.
126## numbl platform: templates & tooling
128Utilities and starting points for building your own
129[numbl](https://numbl.org) projects.
131- **[numbl-figure-viewer](https://github.com/concept-collection/numbl-figure-viewer)**
132 ([live](https://concept-collection.github.io/numbl-figure-viewer/)).
133 Open and explore a figure exported from numbl, including its underlying data.
134- **[numbl-project-example](https://github.com/concept-collection/numbl-project-example)**
135 ([live](https://concept-collection.github.io/numbl-project-example/)).
136 A minimal numbl project deployed to GitHub Pages, meant as a starting
137 template.
138- **[numbl-embed-example](https://github.com/concept-collection/numbl-embed-example)**
139 ([live](https://concept-collection.github.io/numbl-embed-example/)).
140 Shows how to embed editable, runnable numbl scripts inside Markdown rendered
141 on GitHub Pages.