Jukka Aho
64056da96a
Major revision of ADR-002 based on implementation experience.
Decision change:
- OLD (Nov 9): Topology without node count (pure geometry)
- NEW (Nov 13): Topology with node count type parameter
Rationale:
Node count comes from MESH FILES, not from basis choice. When reading
Abaqus .inp, Code Aster .med, or GMSH .msh files, the mesh explicitly
specifies node count in element connectivity:
- Hex element (1,2,...,8) → 8 nodes
- Hex element (1,2,...,20) → 20 nodes
- Hex element (1,2,...,27) → 27 nodes
The mesh reader knows node count BEFORE basis functions are selected.
Therefore, topology must include node count: Hexahedron{N}.
New design:
struct Hexahedron{N} <: AbstractTopology end
const Hex8 = Hexahedron{8}
const Hex20 = Hexahedron{20}
This maintains type stability (N known at compile time) while
acknowledging that N originates from mesh data, not basis choice.
Supersedes: ADR-002 (November 9, 2025)
title, description, date, author, categories, keywords, type
| title | description | date | author | categories | keywords | type | ||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| JuliaFEM Documentation | Three-tier documentation structure for users, contributors, and researchers | 2025-11-09 | Jukka Aho |
|
|
index |
Welcome! JuliaFEM documentation is organized into three manuals for three different audiences:
📘 User Manual - "Just Get It Done"
For: End users, engineers, students who want to run simulations.
Style: Simple, practical, step-by-step.
Contents:
- Quick start and installation
- Tutorials and examples
- API reference
- Troubleshooting
Philosophy: Show me how to solve my problem, skip the lectures.
👉 Start Here if you want to run simulations.
🔧 Contributor Manual - "Show Me the Code"
For: Developers, contributors, advanced users who want to extend JuliaFEM.
Style: Technical, detailed, design rationale.
Contents:
- Testing philosophy
- Code style and architecture
- Performance guidelines
- How to add elements
- CI/CD and git workflow
Philosophy: Explain HOW the code works and WHY we made these choices.
👉 Start Here if you want to contribute code.
📖 The JuliaFEM Book - "Let Me Show You How I Think"
For: Advanced researchers, theory nerds, those who want to understand deeply. And Jukka.
Style: Comprehensive, educational, opinionated, personal.
Contents:
- Mathematical foundations (Lagrange basis, contact mechanics, etc.)
- Design philosophy and technical vision
- Strategic mistakes and lessons learned (2015-2019)
- Research directions (nodal assembly, matrix-free, etc.)
- Personal reflections on the journey
Philosophy: Mix theory, software design, and personal experience. Teach FEM through implementation.
👉 Start Here if you love deep dives and want to understand the "why" behind everything.
Quick Navigation
I want to...
- Solve a heat transfer problem → User Manual
- Add a new element type → Contributor Manual
- Understand Lagrange basis functions → Book: Lagrange Basis
- Learn about testing → Contributor: Testing Philosophy
- See benchmark results → Book: Benchmarks
- Understand the design philosophy → Book: Philosophy
- Report a bug → GitHub Issues
- Ask a question → GitHub Discussions
Documentation Philosophy
Why Three Manuals?
Different readers have different needs:
- Users don't care about implementation details - they just want working code.
- Contributors need technical depth but not necessarily all the theory.
- Researchers (and Jukka) want to understand everything from first principles.
Mixing these audiences in one manual makes it too complex for users and too shallow for researchers.
Design Principles
- User Manual: Optimize for time-to-first-result
- Contributor Manual: Optimize for correctness and maintainability
- Book: Optimize for understanding and education
Cross-References
Manuals link to each other when appropriate:
- User manual links to theory when deeper understanding helps
- Contributor manual links to book for design rationale
- Book links to code examples and practical guides
Contributing to Documentation
Documentation improvements are always welcome!
- User docs: Fix errors, add examples, improve clarity
- Contributor docs: Update for new features, clarify architecture
- Book: Add theory, share insights, document research
See Contributor Manual for guidelines.
License: MIT (same as code)
Questions? Open an issue or discussion on GitHub