Interactive Lab + FAQ

Interactive Lab + FAQ

Generative Radial Geometry (GRG)

A discrete–exact grammar for curves and surfaces using turns, chords, and radial projections. π is not imported as a magic constant; it emerges from dyadic steps and converges in the classical limit.

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Turns-first definitions

We discretize the unit turn; dyadic refinement keeps operations exact on the mesh and drives accuracy.

$$ b \in \mathbb{N}_{\geq 0}, \qquad N = 2^{b} $$
$$ \Delta u = 2^{-(b+2)} \quad \text{(quarter sampling)} \qquad \Rightarrow \qquad \Delta u = \frac{1}{4N}. $$

For a circle of radius \(R\), the inscribed polygon at \(N\) turns has:

$$ P_{N} = 2 N R \sin\!\left(\frac{\pi}{N}\right), \qquad A_{N} = \frac{1}{2} N R^{2} \sin\!\left(\frac{2\pi}{N}\right). $$
Dyadic polygon and chords Circle with an N=16 inscribed polygon, dyadic rays, and a highlighted chord.
Turns, chords, and dyadic rays. Crisp vectors at any zoom.

Interactive Lab

Switch presets and adjust the dyadic exponent \(b\). For the star case \(r(\theta)=1+a\cos(k\theta)\), the exact area is \(A=\pi\!\left(1+\frac{a^{2}}{2}\right)\).

N (turns)
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Perimeter (approx)
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Area (approx)
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Perimeter true
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Area true
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Errors (|P|, |A|)
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Notes. Circle & atlas use exact finite-step formulas (chords) and converge monotonically. Star-shape uses inscribed polygons; C-shape uses odd–even radial sweep for area (perimeter shown exact for reference).

Critical FAQ (condensed)

Q: Is GRG just numerical integration with a trick?
A: For circles with dyadic bisections steps are exact at finite \(N\) (chords & projections). The limit recovers classical values; nothing is imported.

Q: Where does \(\pi\) come from?
A: From the discrete perimeter/area growth of dyadic polygons. \(\pi\) appears as a rotational-symmetry shadow as \(N\to\infty\).

Q: Non-convex shapes “jump across the outside”.
A: We prevent that with visibility-aware schemes: (i) odd–even radial sweep; (ii) radial atlas (locally star-shaped patches with ± signs for outer components/holes).

Q: Convergence?
A: \(O(N^{-2})\) for \(C^{2}\) boundaries; \(O(N^{-1})\) near corners (mitigated via adaptive dyadics). Inscribed perimeter/area are monotone.

Q: Why is GRG pedagogically useful?
A: You can teach Euclidean geometry from bisections and chords; radians & trig tables emerge rather than being prerequisites.

Technical Appendix — Non-Convex & Complex Parametrizations

  1. Star-Check. If a center sees the whole boundary (star-shaped), sample \(\theta\) in dyadic turns and use \(r(\theta)\). Inscribed area/perimeter are monotone \(\uparrow\) with \(O(N^{-2})\).
  2. Odd–Even radial sweep. For each \(\theta_{k}\), intersect the ray with the boundary, sort radii \(r_{k,j}\), and add inside segments \([r_{k,1},\, r_{k,2}],\ [r_{k,3},\, r_{k,4}], \dots\).
  3. Radial atlas (± signs). Decompose into locally star-shaped patches; outer components \(+\), holes \(−\). Sum areas with signs and perimeters by absolute length. Same \(O(N^{-2})\) patch-wise.
  4. Robustness. \(C^{2} \Rightarrow O(N^{-2})\); corners \(\Rightarrow O(N^{-1})\) unless adaptively refined. Self-intersections: use winding rule instead of parity.

All computations use turns, chords, projections; operations are exact at finite dyadic steps for circular primitives and exact on the mesh for polygons.

Team

Roles are presented by responsibility area. Individual bios can be added later.

Team roles pictogram Minimal icons representing research, algorithms, systems, and editorial review.
Role-based structure. Short scope, clear ownership.

Leadership & Research

  • Sets the research agenda and publishes specifications with reproducible examples.
  • Maintains the “turns-first” glossary and consistency across demos and notes.
  • Approves public statements and abstracts before release.

Methods & Algorithms

  • Designs visibility-aware procedures (odd–even sweep, radial atlas with ± signs).
  • Owns convergence studies and baselines for circles, ellipses, and polygons.
  • Runs complexity/accuracy benchmarks; documents limits and mitigations.

Systems & Frontend

  • Implements interactive canvases; keeps demos accessible and performant.
  • Maintains build tooling and test fixtures for numerical correctness.
  • Coordinates localization and analytics (non-invasive, anonymized).

Editorial Review & QA

  • Checks clarity, tone, and scope; enforces the evidence-led style.
  • Validates formulas and captions (MathJax + SVG semantics and accessibility).
  • Controls versioning of figures; ensures non-repetitive hero imagery.

Collaborations

We welcome collaborations with educators and researchers. A public contact form will be added once finalized.

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Guidelines

GRG Documentation Guidelines

Describe the construction through its geometric definitions. Use plain language, explicit hypotheses, and reproducible evidence.

Current Formulas

Use geometric lengths and ratios. Keep circular constants outside the construction’s formulas and numerical kernel. Explicit computational comparisons may use reference constants, with their role clearly stated.

Claims and Evidence

Distinguish definitions, proved statements, numerical observations, proposals, and applications. Do not claim efficiency, numerical stability, exact hardware arithmetic, or originality without supporting evidence.

Versioning

Identify historical formulations and retain their provenance. The binary radial formulation is the current two-dimensional reference.

Presentation

Keep site content in English. Provide accessible diagram descriptions, readable mathematical displays, and verified links. Avoid polemical slogans and comparisons that imply an unmeasured advantage.