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- **[mesh-converter](https://github.com/concept-collection/mesh-converter)**
49 ([live](https://concept-collection.github.io/mesh-converter/)).
50 Convert meshes between 19 formats (PLY, OBJ, STL, VTK, Gmsh, XDMF, …) with
51 [meshio](https://github.com/nschloe/meshio) running in-browser on Pyodide;
52 inspect meshes in 3D and see what a lossy export would drop.
53- **[mesh-pde-solver](https://github.com/concept-collection/mesh-pde-solver)**
54 ([live](https://concept-collection.github.io/mesh-pde-solver/)).
55 Upload a quad surface mesh and solve Poisson or Helmholtz problems on it
56 with [surfacefun](https://github.com/danfortunato/surfacefun), entirely in
57 the browser; the solution renders in a rotatable 3D view.
58- **[mesh-studio](https://github.com/concept-collection/mesh-studio)**
59 ([live](https://concept-collection.github.io/mesh-studio/)).
60 Build CAD primitives or import STEP/IGES with
61 [OpenCASCADE.js](https://ocjs.org/), then inspect them in 3D — including each
62 face's true NURBS surface (polynomials on faces), not just its triangulation.
63- **[qhull-wasm-demo](https://github.com/concept-collection/qhull-wasm-demo)**
64 ([live](https://concept-collection.github.io/qhull-wasm-demo/)).
65 Demos and benchmarks for [qhull-wasm](https://github.com/magland/qhull-wasm),
66 which compiles [Qhull](http://www.qhull.org) to WebAssembly. Includes 2-D
67 Delaunay triangulation, 3-D convex hull, and a Delaunay benchmark with
68 matching scripts for MATLAB, Octave, and numbl.
70## Monte Carlo & sampling
72- **[hitandrun-interactive](https://github.com/concept-collection/hitandrun-interactive)**
73 ([live](https://concept-collection.github.io/hitandrun-interactive/#figure/sampler)).
74 Hit-and-run MCMC sampling of a 2-D convex region, with React driving a numbl
75 script. Resample, make new regions, or play a step-by-step movie of the
76 algorithm.
77- **[walnuts-interactive](https://github.com/concept-collection/walnuts-interactive)**
78 ([live](https://concept-collection.github.io/walnuts-interactive/#figure/sampler)).
79 WALNUTS (the within-orbit adaptive leapfrog No-U-Turn Sampler) drawing from a
80 2-D banana target, with React driving a numbl script. Tune the leapfrog step
81 and error tolerance, or play a step-by-step movie of the orbit-building.
83- **[stan-web-ide](https://github.com/concept-collection/stan-web-ide)**
84 ([live](https://concept-collection.github.io/stan-web-ide/)).
85 Run [Stan](https://mc-stan.org) sampling in your browser, in a VS Code-style
86 IDE.
88## Peer-to-peer shared state
90- **[commonview](https://github.com/concept-collection/commonview)**
91 ([live](https://concept-collection.github.io/commonview/)).
92 A minimal peer-to-peer page where every visitor shares one state (a counter):
93 nostr discovery, a WebRTC mesh, and a central-peer authority. The basis for
94 hitandrun-commonview.
95- **[hitandrun-commonview](https://github.com/concept-collection/hitandrun-commonview)**
96 ([live](https://concept-collection.github.io/hitandrun-commonview/)).
97 The hit-and-run figure with a single live view shared by all visitors over a
98 WebRTC mesh; one peer runs the sampler via numbl and broadcasts to the rest.
100## Scientific data compression
102- **[benchcompress](https://github.com/concept-collection/benchcompress)**
103 ([results](https://concept-collection.github.io/benchcompress/),
104 [paper (WIP)](https://concept-collection.github.io/benchcompress/paper)).
105 A benchmarking framework that measures compression ratio and encode/decode
106 throughput for compression algorithms on scientific data arrays.
107- **[ephys_compression_tests](https://github.com/concept-collection/ephys_compression_tests)**
108 ([results](https://concept-collection.github.io/ephys_compression_tests/)).
109 Compression benchmarks for electrophysiology recordings.
110- **[ans-visualizer](https://github.com/concept-collection/ans-visualizer)**
111 ([live](https://concept-collection.github.io/ans-visualizer/)).
112 A step-by-step visualizer for the Asymmetric Numeral Systems (ANS)
113 entropy-coding algorithm ([Duda et al., 2015](https://ieeexplore.ieee.org/abstract/document/7170048)).
115## Neurophysiology data & remote access
117- **[remote-hdf5-lazy-read](https://github.com/concept-collection/remote-hdf5-lazy-read)**
118 ([live](https://concept-collection.github.io/remote-hdf5-lazy-read/)).
119 Shows how [neurosift](https://neurosift.app/) browses large remote
120 [NWB](https://www.nwb.org/)/HDF5 files in the browser using HTTP range
121 requests, with no full download and no backend.
122- **[dandiset_000986](https://github.com/concept-collection/dandiset_000986)**
123 ([visualizations](https://concept-collection.github.io/dandiset_000986/)).
124 Reproducible figures and visualizations for
125 [DANDI Dandiset 000986](https://dandiarchive.org/dandiset/000986), a set of
126 mouse auditory cortex recordings.
128## Number theory & visual math
130- **[finite-field-visualizer](https://github.com/concept-collection/finite-field-visualizer)**
131 ([live](https://concept-collection.github.io/finite-field-visualizer/)).
132 Color-coded multiplication tables over finite (prime) fields. Step through the
133 primes to watch the structure change.
134- **[gcd-visualizer](https://github.com/concept-collection/gcd-visualizer)**
135 ([live](https://concept-collection.github.io/gcd-visualizer/)).
136 A heatmap of the greatest common divisor of every pair (i, j), laid out as a
137 color-coded table.
139## Image processing
141- **[numbl-image-filter](https://github.com/concept-collection/numbl-image-filter)**
142 ([live](https://concept-collection.github.io/numbl-image-filter/)).
143 Upload an image, write a MATLAB-syntax filter, and run it on the image in the
144 browser.
146## numbl platform: templates & tooling
148Utilities and starting points for building your own
149[numbl](https://numbl.org) projects.
151- **[numbl-web-ide](https://github.com/concept-collection/numbl-web-ide)**
152 ([live](https://concept-collection.github.io/numbl-web-ide/)).
153 Run MATLAB-syntax .m files in your browser, in a VS Code-style IDE.
154- **[numbl-figure-viewer](https://github.com/concept-collection/numbl-figure-viewer)**
155 ([live](https://concept-collection.github.io/numbl-figure-viewer/)).
156 Open and explore a figure exported from numbl, including its underlying data.
157- **[numbl-project-example](https://github.com/concept-collection/numbl-project-example)**
158 ([live](https://concept-collection.github.io/numbl-project-example/)).
159 A minimal numbl project deployed to GitHub Pages, meant as a starting
160 template.
161- **[numbl-embed-example](https://github.com/concept-collection/numbl-embed-example)**
162 ([live](https://concept-collection.github.io/numbl-embed-example/)).
163 Shows how to embed editable, runnable numbl scripts inside Markdown rendered
164 on GitHub Pages.