A shared vocabulary for the other docs. If a term shows up in a flag table or a schema field and you're not sure what it means, the answer is probably here.
| Term | Definition |
|---|---|
| bucket | One slot in the colormap. A cell's value is mapped to a bucket; the bucket picks the color and the glyph. |
| palette | The ordered list of colors used to fill buckets, low to high. |
| glyph | The character drawn in a cell. Each bucket has one glyph; the palette colors it. |
| spacer | The character placed between cells. Default is a single space. Set to "" for a dense grid. |
| prefix | The left-margin region used for row labels. Width is computed from the longest label. |
| viewport | The drawable width — terminal columns minus prefix. Trim and pad are computed against the viewport. |
| direction | Which edge real data anchors to: ltr (default) anchors on the left, rtl anchors on the right. Controls which edge trim/pad happen on. |
| padding | When data is narrower than the viewport and --pad-to-width is set, extra zero-valued, unlabeled cells fill the side opposite direction. |
| trim | When data is wider than the viewport, columns are dropped from the side opposite direction. |
| normalize | The bucketing strategy. linear bins values evenly across [vmin, vmax]. quantile reserves bucket 0 for v <= 0 and bins the rest by quantile (the GitHub look). |
| gamma | Exponent applied during linear bucketing. Lower = more contrast at the low end. Ignored under quantile. |
| vmin / vmax | The colormap's lower and upper bounds. Computed from the data if unset. |
| header | The row(s) of column labels. Position controlled by invert_headers; orientation by header_orientation. |
| message | Footer text. Accepts template placeholders. |
| legend | Right-aligned footer text next to the message. Same template machinery. |
| template | A string with [NAME] placeholders expanded at render time ([GRADIENT], [CELL:i], [MIN], [MAX], [TOTAL], [COUNT], [MEAN], [CELLS], [FROM], [TO]). |
| matrix doc | The JSON object heatgraph reads from stdin. See SCHEMA.md#matrix-doc. |
| calendar doc | A sparse, date-keyed JSON object that cal2matrix consumes. See SCHEMA.md#calendar-doc. |
| follow mode | --follow reads NDJSON and redraws each line as a new frame in place. See SCHEMA.md#streaming-follow-mode. |