Venn and Euler · Three sets
Seven explicit measurements; circles may approximate the areas.
Use for membership relationships between up to three sets. Euler containment and disjoint arrangements use the same data contract and circle geometry; they are not a separate renderer. Use a table for precise comparisons: not every combination of measurements has an exact circular representation.
Declare sets with stable IDs and labels. Provide every nonempty combination in data, including explicit zero or null. A pair intersection includes the triple intersection. Values must be finite, nonnegative and consistent with the parent totals. Null means unknown.
layout.padding controls spacing from 0 to 64 logical points. Colours and set display names belong to appearance.series. Legend visibility recalculates the visible relationships. Venn has no numeric axes, zoom, stacking, markers or shared tooltip. Three-set layouts report their area residual; original measurements never change.