scale-x-date
Continuous x scale that formats axis labels as dates.
Column values may be numeric days since 2000-01-01 or ISO-8601 strings of the form YYYY-MM-DD. Each break is converted via datetime(year: 2000, month: 1, day: 1) + duration(days: int(n)) and rendered with dt.display(date-format).
Usage
scale-x-date(
name: none,
limits: none,
oob: "drop",
breaks: auto,
labels: auto,
expand: auto,
date-format: "[year]-[month repr:numerical]-[day]",
)Parameters
| Parameter | Default | Description |
|---|---|---|
name |
none |
Axis title. Overrides any name set via labels when both are present. |
limits |
none |
Pair (lo, hi) clipping the trained domain (numeric days since 2000-01-01 or ISO-8601 YYYY-MM-DD strings; either side may be auto), or none for automatic limits. |
oob |
"drop" |
Out-of-range policy: "drop" (default) removes rows whose value falls outside limits; "squish" clamps continuous values to the nearest endpoint. |
breaks |
auto |
Array of break values (numeric days since 2000-01-01 or ISO-8601 YYYY-MM-DD strings), or auto for automatic tick selection. |
labels |
auto |
Array of tick labels aligned with breaks, or auto. |
expand |
auto |
Padding around the domain. Accepts a ratio (5%) for proportional breathing room, a length (5pt) for canvas-space padding, a relative (5pt + 5%) for both, or a (lo, hi) 2-tuple for asymmetric padding, where either element may be auto to keep the per-scale default on that side. auto keeps the per-scale default; false collapses to zero. |
date-format |
"[year]-[month repr:numerical]-[day]" |
Typst datetime.display pattern used for break labels. |
Returns
Scale object consumed by plot.
Examples
Numeric days since 2000-01-01 formatted as year-month ticks.
#let d = range(0, 12).map(i => (x: 8766 + 30 * i, y: i))
#plot(
data: d,
mapping: aes(x: "x", y: "y"),
layers: (geom-line(), geom-point(size: 2pt)),
scales: (scale-x-date(date-format: "[year]-[month repr:numerical]"),),
width: 12cm,
height: 6cm,
)
ISO-8601 strings work just as well; pick a longer date-format to spell the month out.
#let d = (
(x: "2024-01-15", y: 1),
(x: "2024-04-15", y: 4),
(x: "2024-07-15", y: 9),
(x: "2024-10-15", y: 16),
)
#plot(
data: d,
mapping: aes(x: "x", y: "y"),
layers: (geom-line(), geom-point(size: 2pt)),
scales: (scale-x-date(date-format: "[month repr:short] [year]"),),
width: 12cm,
height: 6cm,
)
