Formula Library

中文文档 | English Doc

A responsive LaTeX and Mermaid editor for Obsidian with MathLive WYSIWYG editing, 2216 categorized formulas, smart search (pinyin, LaTeX commands, fuzzy matching), and extensible formula folders for user customization.

Features

• MathLive Visual Editor: WYSIWYG formula editing with real-time preview and virtual keyboard
• 2216 Formulas: 19 categories, including 95 formulas for algorithms, information theory, machine learning, graphics, signals, and numerical computing
• Smart Search: Pinyin initials, LaTeX command aliases, word-based English matching, abbreviation matching (e.g., "lt" → less than), and fuzzy matching
• Usage Frequency Sorting: Formulas you use most appear first — search results and category lists are sorted by insertion count
• Formula Controls: Favorites, pins, recent items, hidden formulas, smart/usage/recent/name sorting, card density, and result limits
• Mermaid Diagrams: 11 templates; flowcharts and state diagrams include node/connection visual editing, with centered preview and Markdown insertion for every type
• Configurable Shortcuts: Custom keyboard shortcuts for fraction, sqrt, superscript, subscript (default: unbound)
• Matrix Templates: cases, matrix, bmatrix, pmatrix, jacobian, hessian, identity, diagonal, augmented
• Visual / Source Mode: Toggle between WYSIWYG and raw LaTeX editing
• Edit Existing Formulas: Place cursor inside $...$ or $$...$$ and run command to edit
• Sidebar Quick Insert: Click formulas in the sidebar to insert directly
• Group Dropdown: Category selector as dropdown for compact sidebar layout
• Settings Page: Language, insert format, editor mode, shortcuts, font size/style, density, sorting, search limits, labels, and formula group toggles
• Extensible Formula Folders: Add custom formula groups by dropping JSON files into formulas/
• Bilingual: Full Chinese/English localization, follows Obsidian language setting

Installation

Manual

1. Copy obsidian-formula-library folder to your Vault's .obsidian/plugins/ directory
2. Enable in Obsidian Settings > Community Plugins
3. (Optional) Set a hotkey for "Open Formula Editor" in Settings > Hotkeys

BRAT

1. Install the BRAT plugin in Obsidian
2. Open BRAT settings, click "Add Beta plugin"
3. Enter: strangelion/obsidian-formula-library
4. Restart Obsidian after installation

Usage

Formula Editor

• Command Palette: Ctrl+P → "Open Formula Editor"
• Ribbon Icon: Click the Σ icon on the left
• Select a formula category on the right, click a formula to insert into the editor
• Click Insert (or Shift+Enter) to write the formula to your note

Mermaid Diagram Editor

• Command Palette: Ctrl+P → "Open Mermaid Diagram Editor"
• Flowcharts and state diagrams switch between Visual / Source modes, with direct node, connection, direction, shape, and label controls
• Templates include flowchart, mind map, sequence, state, class, ER, Gantt, timeline, pie, quadrant, and Git graph
• When Excalidraw is installed, the toolbar exposes a shortcut for freehand and drag-and-drop drawing
• Click Insert diagram (or Shift+Enter) to insert a native Mermaid code block

Sidebar Quick Insert

• Click the Σ icon to toggle the sidebar
• Use the dropdown to switch categories
• Click ☆ to favorite a formula, click ★ to unfavorite
• Click a formula to insert directly at cursor position
• Most-used formulas appear first in each category

Edit Existing Formulas

• Place cursor inside $...$ or $$...$$
• Run command "Edit Formula at Cursor"
• Modify and click Update

Formula Categories

Custom Formulas

Formula data is stored in the formulas/ folder inside the plugin directory, with one JSON file per category. Users can add new formulas or categories directly.

BRAT Compatibility: The plugin includes embedded fallback data in main.js. If the formulas/ folder cannot be loaded, the plugin automatically uses the fallback. When releasing, include the entire formulas/ folder in your release assets.

File Structure

formulas/
  _index.json          # Category ordering (optional, auto-discovered if missing)
  _strings.json        # UI translation strings
  greek.json           # Greek letters
  structures.json      # Structures
  analysis.json        # Analysis
  ...                  # Other categories

Adding Formulas to an Existing Category

Edit the corresponding JSON file and add new formulas to the items array:

{
  "id": "greek",
  "structures": false,
  "items": [
    ["α", "\\alpha"],
    ["β", "\\beta"],
    ["Custom", "\\mycommand{#?}", "Custom Formula"]
  ]
}

Adding a New Category

1. Create a new JSON file in the formulas/ directory (e.g., mycategory.json):

{
  "id": "mycategory",
  "structures": false,
  "items": [
    ["Formula Name", "\\latex{code}", "English Name"]
  ]
}

2. Add the category ID to the order array in _index.json:

{
  "order": ["greek", "structures", "...", "mycategory"]
}

If _index.json doesn't exist or doesn't include the new category ID, the plugin auto-discovers and loads groups alphabetically.

Formula Format

Each formula is an array: [label_zh, LaTeX code, label_en (optional)]

• Simple: ["α", "\\alpha"]
• With English label: ["Fraction", "\\frac{#?}{#?}", "Fraction"]
• Section marker: {"section": "Section Title", "sectionEn": "Section Title"}
• Matrix template: ["Matrix", "matrix:matrix", "Matrix"] (prefix matrix: triggers template)

Development

# Syntax check
node -c main.js

Acknowledgments

Formula library extracted from LaTeXSnipper Office Plugin Rendering uses Obsidian's built-in MathJax and MathLive