# Super Scatter

> An enhanced scatter with a live fit line and stats

Canonical: https://ext.tableauops.com/knowledge/kit/super-scatter
Updated: 2026-09-18
Author: Eric Summers

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`](../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/.css` edits (right-click → **Reload**); for any `.trex` change,
> remove and re-add the extension.

## Get it

Super Scatter ships in the Extension Kit ($59). See it live on the [demo gallery](/kit/demo/super-scatter).


---
Try it live: See it live — https://ext.tableauops.com/kit/demo/super-scatter