| 1 | # Chart Expression Vocabulary |
| 2 | |
| 3 | This is the complete planning-side map of the 33 canonical Chart references. |
| 4 | Choose from the page's actual information relationship, then retain the exact |
| 5 | `chart/<key>` identifier. This file deliberately contains no SVG construction, |
| 6 | data-binding, coordinate, label-placement, styling, or export instructions; |
| 7 | those decisions belong to Executor after selection. |
| 8 | |
| 9 | **Reference — not a constraint**: each description states what the visual |
| 10 | encoding represents. It is not a ranking, recommendation, threshold, quota, or |
| 11 | substitute for judgment from the current data and communication goal. Zero |
| 12 | Chart selections remains valid. |
| 13 | |
| 14 | ## 1. Change over time |
| 15 | |
| 16 | | Canonical reference | Encoded relationship | |
| 17 | |---|---| |
| 18 | | `chart/line_chart` | Values positioned along a continuous axis, with connected marks showing change or direction. | |
| 19 | | `chart/area_chart` | A continuous series whose filled area emphasizes magnitude across the axis. | |
| 20 | | `chart/stacked_area_chart` | Multiple filled series whose layers encode both total magnitude and changing composition. | |
| 21 | | `chart/dual_axis_line_chart` | Two continuous series measured on separate value scales. | |
| 22 | | `chart/stock_chart` | Open, high, low, and close values across ordered dates. | |
| 23 | | `chart/waterfall_chart` | Sequential positive and negative contributions connecting a starting value to an ending value. | |
| 24 | |
| 25 | ## 2. Category comparison and rank |
| 26 | |
| 27 | | Canonical reference | Encoded relationship | |
| 28 | |---|---| |
| 29 | | `chart/column_chart` | Category values encoded by vertical length from a shared baseline. | |
| 30 | | `chart/horizontal_bar_chart` | Category values encoded by horizontal length from a shared baseline. | |
| 31 | | `chart/grouped_bar_chart` | Multiple series placed side by side within shared categories. | |
| 32 | | `chart/stacked_bar_chart` | Category totals divided into value-driven component lengths. | |
| 33 | | `chart/butterfly_chart` | Two datasets mirrored around one shared category axis. | |
| 34 | | `chart/dumbbell_chart` | Two values per item joined to expose their gap and direction. | |
| 35 | | `chart/pareto_chart` | Descending category contributions paired with their cumulative share. | |
| 36 | |
| 37 | ## 3. Target and progress |
| 38 | |
| 39 | | Canonical reference | Encoded relationship | |
| 40 | |---|---| |
| 41 | | `chart/bullet_chart` | Actual values, targets, and optional performance bands on compact linear scales. | |
| 42 | | `chart/progress_bar_chart` | Bounded completion values encoded as filled portions of linear tracks. | |
| 43 | | `chart/gauge_chart` | One bounded value positioned against a circular or semicircular domain and reference marks. | |
| 44 | |
| 45 | ## 4. Distribution and multivariable relationship |
| 46 | |
| 47 | | Canonical reference | Encoded relationship | |
| 48 | |---|---| |
| 49 | | `chart/histogram_chart` | Observation frequency encoded across contiguous numeric bins. | |
| 50 | | `chart/box_plot_chart` | Median, quartiles, spread, and outliers summarized for one or more groups. | |
| 51 | | `chart/scatter_chart` | Two numeric variables encoded by x/y position. | |
| 52 | | `chart/bubble_chart` | Two variables encoded by x/y position and a third by mark size. | |
| 53 | | `chart/heatmap_chart` | Values at row-column intersections encoded by color intensity. | |
| 54 | | `chart/radar_chart` | Multiple measures positioned on radial axes for one or more entities. | |
| 55 | | `chart/matrix_2x2` | Items positioned by two numeric dimensions, with optional magnitude encoded by radius. | |
| 56 | |
| 57 | ## 5. Part-to-whole and hierarchy |
| 58 | |
| 59 | | Canonical reference | Encoded relationship | |
| 60 | |---|---| |
| 61 | | `chart/pie_chart` | Flat parts of one whole encoded by sector angle and area. | |
| 62 | | `chart/donut_chart` | Flat parts of one whole encoded around an open center. | |
| 63 | | `chart/pie_of_pie_chart` | One composition with selected parts expanded into a secondary pie. | |
| 64 | | `chart/bar_of_pie_chart` | One composition with selected parts expanded into a secondary stacked bar. | |
| 65 | | `chart/treemap_chart` | Hierarchical or grouped parts encoded as nested rectangular areas. | |
| 66 | | `chart/sunburst_chart` | Hierarchical parts encoded as concentric radial levels and angular spans. | |
| 67 | |
| 68 | ## 6. Flow, schedule, and weighted text |
| 69 | |
| 70 | | Canonical reference | Encoded relationship | |
| 71 | |---|---| |
| 72 | | `chart/funnel_chart` | Ordered stage values encoded as changing widths through a conversion sequence. | |
| 73 | | `chart/sankey_chart` | Magnitude moving between nodes encoded by connection width. | |
| 74 | | `chart/gantt_chart` | Tasks positioned and sized by dates or durations along a time axis. | |
| 75 | | `chart/word_cloud` | Term weight or frequency encoded by type size. | |
| 76 |