Line

A line is the right default for a continuous numeric trend over time (or any naturally ordered x). Multiple series share the same axes via stroke.

Single series

```plot view=daily_signups
Plot.line(data, { x: "date", y: "count" })
```

Multiple series

```plot view=daily_signups_by_source
Plot.line(data, { x: "date", y: "count", stroke: "source" })
```

With markers and tooltip

```plot view=daily_signups
{
  marks: [
    Plot.line(data, { x: "date", y: "count" }),
    Plot.dot(data, { x: "date", y: "count", r: 3 }),
    Plot.tip(data, Plot.pointer({ x: "date", y: "count" })),
  ]
}
```

Common options

Option	Meaning
x, y	column names (x is usually a date or ordered numeric)
stroke	column name → series color
strokeWidth	line thickness in px
strokeDasharray	e.g. "4 2" for dashed lines
curve	"linear" (default), "monotone-x", "step", "basis", "natural"
marker	true or "circle", "arrow", etc. for per-point markers
z	column name → grouping (use when stroke isn’t set)
tip	true for hover tooltips

See Observable Plot — line for the full reference.