TheJIT Histogram Maker

Build histograms with a complete start + width + count bin contract, documented presets, and raw-value or frequency-table input.

Open the live Histogram Maker

What it does

• Set the first class boundary, interval width, and bin count together.

• Use Sturges, square-root, or Freedman–Diaconis with the formula shown.

• Overlay an optional per-group normal reference curve without changing the bins.

• Paste raw values by group or a Value + Frequency table.

• Copy or download the exact frequency table behind the bars.

• Paste CSV, TSV, semicolon-separated, or pipe-separated text.

• Keep the latest draft in this browser, or save and reopen a local project.

• Export watermark-free SVG and 1×, 2×, 4×, or 6× PNG.

• Copy SVG, create a URL-fragment share link, or download the evidence ZIP.

• Add a source note without sending source rows to a chart service.

Privacy by architecture

Parsing, calculation, SVG layout, autosave, share-link encoding, and export run in the current browser tab. The production modules in src/ have no dataset upload endpoint, telemetry call, account system, or third-party chart runtime.

URL-fragment sharing is not encryption. Anyone who receives a link can read the encoded data, so use a local project file for sensitive or large datasets.

Source layout

• src/lab-core.js — defensive table parsing, safe SVG helpers, and export.
• src/stats-core.js — shared parser, summaries, quartiles, bins, stems, and renderer.
• src/stats-app.js — autosave, local projects, URL fragments, and evidence exports.
• src/wp-lab.css — the production Visual Lab interface styles.
• SOURCE_MANIFEST.json — SHA-256 hashes of the production-derived modules.

The files in src/ are copied from Visual Lab 0.12.1; the manifest lets you compare a published repository with the matching release package.

Run the demo

Serve the repository over localhost so browser modules can load:

python3 -m http.server 8000 --bind 127.0.0.1

Then open http://127.0.0.1:8000/demo/.

Test

npm test

The calculation tests have no package dependencies.

Deliberate limits

The shared statistics engine accepts one to four groups and up to 10,000 expanded observations. It does not add violin, notched-box, stacked-histogram, or decorative jitter modes.

License

MIT