Sankey · Missing link
Known totals remain explicitly incomplete.
Use Sankey for nonnegative quantities moving between named nodes. Ribbon thickness uses one common scale; a node spans the larger known incoming or outgoing total. Position is layout, not a measured X/Y coordinate.
Supply up to 128 nodes with id, label and optional groupId, and up to 512 links with id, from, to and finite nonnegative value or null. Node and link IDs are unique across the diagram. The graph must be acyclic; parallel links with different IDs are allowed. Zero is valid without a fictitious ribbon. Missing links are not painted and affected node totals are marked incomplete.
Use options.layout for horizontal/vertical orientation, nodeWidth(2–64) and nodePadding(0–64). Group legends remove incident links and recalculate the visible flow scale. Point tooltips, pinning, normalized XY zoom and accessible navigation are supported. Shared tooltips, Cartesian axes, stacking and reference lines are incompatible. Subpixel geometry can be omitted while identity and the positive source value remain inspectable; it is never widened or converted to zero.