sankey

Use for directed flows between nodes. One row = one link: x source, series target (required), y flow ≥ 0. Keep input row order. Nodes = unique x ∪ series. Self-links (x value equals series value) → E_UNKNOWN_FIELD. A cycle → E_SANKEY_CYCLE. A repeated source/target pair → E_DUP_KEY. Equal values share one thickness. Negatives → E_NEGATIVE_VALUE.

Do not use for hierarchical part-to-whole (treemap) or ordered stage drop-off (funnel).

x category (source) · y number (flow ≥ 0) · series required (target)

Rules. One row = one link. Keep order. Self-link → E_UNKNOWN_FIELD. A cycle → E_SANKEY_CYCLE. Equal values share one thickness. A repeated source/target pair → E_DUP_KEY.

Example

markvis: 2
type: sankey
title: Five Points still feeds Midtown before Arts Center
x: from
y: riders
series: to

from,to,riders
North Springs,Five Points,620
Airport,Five Points,540
Five Points,Midtown,880
Five Points,Peachtree Center,410
Midtown,Arts Center,390

Five Points still feeds Midtown before Arts Center

from	to	riders
North Springs	Five Points	620
Airport	Five Points	540
Five Points	Midtown	880
Five Points	Peachtree Center	410
Midtown	Arts Center	390

When the block is wrong

The rows stay, with one line that names the error.

markvis: 2
type: sankey
title: Self link
x: from
y: riders
series: to

from,to,riders
Five Points,Five Points,120

from	to	riders
Five Points	Five Points	120

E_UNKNOWN_FIELD: sankey self-link (source equals target)

Generated from packages/types/sankey/ and the type's row in SPEC.md.