A custom mark type for one worksheet: bind two measures and it draws a live scatterplot with descriptive stats + correlation that recompute as you brush or click to select points.
Shared viz-extension techniques (reading encodings, live updates, responsive/no-scroll degradation, color scales, selection, the single-point trap) are not repeated here, > they live globally in
reference/viz-extensions.md. This file covers only what's specific to Super-Scatter.
#What it is
- Scatter of X vs Y with a least-squares fit line.
- Stats panel: point count, Pearson r, R², regression equation, and per-axis mean / median / std / min / max / sum.
- Brush (drag) or click points to select a subset → stats + fit line recompute over it; double-click / clear resets.
#Encodings (Marks card)
| Tile | Required | Accepts |
|---|---|---|
| X | yes | one continuous measure |
| Y | yes | one continuous measure |
| Detail | no | one dimension, one point per mark (e.g. Customer); also enables push-selection |
| Color | no | one dimension/measure, colors the points |
#Run it locally
From the repo root: python scripts/kitserve.py (serves every extension on 8765).
It answers on both IPv4 and IPv6 and resolves lib/ to _shared/lib; a plain
python -m http.server does neither, which is what makes a local extension load
as a blank or errored zone.
In Tableau, on a worksheet's Marks card → mark-type dropdown → Add Extension… →
Access Local Extensions → manifest.local.trex. Bind SUM(Sales)→X, SUM(Profit)→Y,
Customer Name→Detail.
Reload after
.html/.js/.cssedits (right-click → Reload); for any.trexchange, remove and re-add the extension.