new·The score now tells you which way it movedA brain's exam only ever grows: its own material writes questions, and so does every question a real caller asked and did not get answered. The score is a percentage over that growing set, so a brain that learned more could post a smaller number — and this week three did. One of them answered two MORE questions than the week before and showed eighteen points less. Printed as a single percentage, that reads as decline to a reader and as punishment to anyone who contributes material.all news →
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D3

Answer questions about D3 as documented today: selections and the data join, scales and axes, shapes and generators for line, area, arc and pie, hierarchies and treemaps, forces, geographic projections, transitions, and the array and format utilities — with exact signatures for each module.

1,875 notes · updated 2026-08-10 · trained 79%

use this brain
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$ claude mcp add --transport http mozg \
https://mozg.sh/mcp --header "Authorization: Bearer …"
> use mozg/d3 — …
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Ask it things like

answers 61/75 on its latest exam
What is the basic workflow for d3-force?Forces and Simulation✓
What does selection.join() return and how does it handle enter, update, and exit selections?Selections and Data Join✓
How do I bind data to DOM elements using d3.selectAll and data()?Selections and Data Join✓
What is the signature of geoPath()?Geographic Projections✓
What is the signature of d3.scaleOrdinal()?Scales and Axes✓
What does quantile.domain() do?Scales and Axes✓
What does selection.select() do and how does it differ from selectAll()?Selections and Data Join✓
What is the signature of d3.selectAll()?Selections and Data Join✓

What it can answer

75 coverage checks
79%
Answers 61 of the exam's 75 questions
▲Shapes and Generators21 / 25
▲Hierarchies and Layouts10 / 14
▲Forces and Simulation9 / 13
▲Scales and Axes9 / 10
▲Selections and Data Join7 / 8
✓Geographic Projections5 / 5
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Attacks survived

re-run weekly · 2026-08-11
✓gate-battery12/12 known hostile payloads caught by the ingest gate
✓injection-corpusevery active note scanned — no steering language
✓secret-corpusevery active note scanned — no keys or credentials

heuristic scans against known attack classes — measured and dated, not a promise of unpoisonability

Inside

  • zoom.constrain(constrain) default constraint function · d3-zoom
  • zoom.wheelDelta(delta) default wheel delta function · d3-zoom
  • zoom.transform(selection, transform, point) signature and behavior · d3-zoom
  • zoom.scaleTo(selection, k, p) signature and behavior · d3-zoom
  • zoom() constructor · d3-zoom
  • zoom.touchable(touchable) default touch detector · d3-zoom
  • Pitfall: transform application order matters · d3-zoom
  • zoom(selection) applies behavior and event listeners · d3-zoom
  • zoom.translateBy(selection, x, y) signature and behavior · d3-zoom
  • zoom.translateTo(selection, x, y, p) signature and behavior · d3-zoom
  • Unbinding zoom behavior · d3-zoom
  • Example: apply zoom transform to SVG · d3-zoom
  • zoom.filter(filter) default filter function · d3-zoom
  • zoom.extent(extent) viewport extent · d3-zoom

Licence

CC BY-NC-SA 4.0

Use it, copy it, build on it, with credit. Selling it is not allowed.