Plodder

Try Plodder online

Plodder is a standalone local plot digitizer. Upload a graph image, calibrate axes with multiple X/Y markers, verify with phantom points, digitize with a smoothed line overlay, refine with Best Fit (snap + simplify + undo), and export CSV, JSON, or Python.

Features

• Multiple axis calibration points — piecewise fit for accurate scales
• Phantom verification points — place or auto-generate grid phantoms labeled with interpolated X/Y
• Main-image zoom & pan — scroll to zoom, Space/Alt+drag to pan
• Smoothed Trace line overlay — Catmull-Rom curve through points
• Best Fit — snap points onto the ink using local curve slope; simplify redundant points; undo stack
• Save / load project — resume calibration and digitized points (.plodder.json)
• Linear, Log₁₀, Logₑ, Log₂, reciprocal, √x, x², and asinh scales

Requirements

• Node.js 20+
• A modern browser (runs entirely client-side; no backend)

Run

npm install
npm run dev

Then open the URL Vite prints (usually http://localhost:5173).

npm run build    # typecheck + production build → dist/
npm run preview  # serve the production build locally
npm run lint     # oxlint

Workflow

1. Upload or drop a plot image (or load from URL)
2. Calibrate X / Y — markers are seeded on a detected plot rectangle when possible; drag/add markers and enter known values (≥2 per axis). Use Log₁₀ (etc.) for log plots.
3. Phantoms — optional checks on known ticks
4. Trace line — left-click to add points; right-click to delete; click near the line to insert
5. Best Fit — Snap to curve, Simplify, Undo
6. Save project and/or export CSV · JSON · Python

Save & resume

Save downloads a self-contained .plodder.json with the image, X/Y calibration markers, phantoms, and digitized points. Load (or drop the file) restores the session so you don’t recalibrate.

Project layout

src/
  App.tsx                 # UI composition
  types.ts                # Shared domain types
  hooks/                  # Session, Best Fit, view transform
  components/             # Canvas, panels, toolbar
  lib/                    # Calibration, export, geometry, project I/O

All digitizing math lives in this repo (no external CV or charting libraries). Runtime dependency: React only.

GitHub Pages

Pushes to main build and deploy via .github/workflows/pages.yml.

1. Ensure the repository name matches PAGES_BASE_PATH in the workflow (default /plotter/).
2. In the repo: Settings → Pages → Source: GitHub Actions.
3. Push main (or run Actions → Deploy to GitHub Pages → Run workflow).

Local production build with the Pages base path:

# PowerShell
$env:VITE_BASE_PATH="/plotter/"; npm run build; npm run preview

# bash
VITE_BASE_PATH=/plotter/ npm run build && npm run preview

License

Licensed under the Apache License 2.0.