Gantt Chart

Source: Data Visualisation Catalogue - Gantt Chart

Why This Belongs In The Compiler Gallery

The catalogue describes Gantt charts as timelines of tasks or activities with start and end positions. This chart now exercises the compiler's temporal interval path: raw date fields compile into normalized intervals, then a time scale and generated date axis render the shared schedule.

Data Contract

Each raw row represents one task or activity interval.

Field	Type	Purpose
`task`	categorical	Task label shown on the categorical axis.
`phase`	categorical, optional	Higher-level grouping or lane.
`startDate`	temporal	Raw start date.
`endDate`	temporal	Raw end date.
`status`	categorical, optional	Color grouping.
`start`	temporal, derived	Normalized interval start date.
`end`	temporal, derived	Normalized interval end date.
`duration`	quantitative, derived	Interval length in days.

Expected Visual

The faithful catalogue version should show horizontal bars positioned on a shared timeline. Bar length encodes duration, vertical position identifies the task, and color may encode status or phase.

Element	Expected treatment
Task bars	Rects using `start` and `end` bounds on a shared x scale.
Task labels	Band-axis labels keyed by task.
Timeline	Continuous or temporal x axis with gridlines.
Milestones	Optional guide lines or markers on the same x scale.
Color	Optional categorical encoding for phase or status.

Compiler Mapping

Compiler part	Mapping
Data source	`tasks` raw table and derived `intervals` table.
Transform	`interval` to compute `start`, `end`, `duration`, center, tooltip, and duration label.
Scales	`x: time`, `y: band`, `color: ordinal`.
Layers	`rect` interval bars, `line` milestone/grid guides, `text` duration labels.
Interaction	Hover should expose task, start, end, duration, status, and source row.

Faithfulness Notes