CHORD

Use when

• WARN: editorial overviews of dense mutual exchange between few nodes
• showing that everything trades with everything, not how much

Do not use when

• reading any specific flow (ribbon widths at a glance mislead)
• sparse matrices (a sankey tells it straight)

See instead

• flows must be read: CH-FLO-02
• exact values per pair: CH-TAB-02

Alternatives

• CH-FLO-02 (readable flows, planned/built as sankey)
• CH-TAB-02 (exact matrix values)

Rules

• node arcs sized by total in+out; labels carry the totals
• ribbons colored by source, monochrome ramp
• diagonal must be zero: self-flows are not flows

Never do this

• WARN ENTRY: chord diagrams decorate; CH-TAB-02 or a sankey informs
• self-loops
• more than 6 nodes
• rainbow ribbons

QA before delivering

• square matrix, zero diagonal
• <= 6 nodes
• totals printed
• source present

Data shape

{
  "title": "The north-central lane carries the heaviest exchange",
  "eyebrow": "INTER-YARD TRANSFERS . JUNE",
  "source": "Source: sample dataset v1, 2026-07-12",
  "unit": "loads",
  "nodes": [
    "North",
    "Central",
    "South",
    "East",
    "West"
  ],
  "flows": [
    [
      0,
      18,
      6,
      4,
      2
    ],
    [
      12,
      0,
      8,
      5,
      3
    ],
    [
      4,
      6,
      0,
      3,
      2
    ],
    [
      3,
      4,
      2,
      0,
      1
    ],
    [
      2,
      2,
      1,
      1,
      0
    ]
  ]
}