Plots

A Plot block is a fenced markdown block whose body is an Observable Plot expression. PlotPress runs the named view, exposes the result as data, and renders the result of your expression.

Cheat sheet

Chart	Mark	Use it for	Page
Bar	Plot.barY / Plot.barX	counts, sums, comparisons across categories	Bar
Line	Plot.line	time series, monotone trends	Line
Area	Plot.areaY	stacked time series, cumulative volume	Area
Dot (scatter)	Plot.dot	two-dimensional relationships, outliers	Dot
Histogram	Plot.rectY + Plot.binX	distribution of a single numeric variable	Histogram
Heatmap	Plot.cell	dense 2D categorical or binned data	Heatmap
Box plot	Plot.boxY / Plot.boxX	distribution + outliers across categories	Box plot

How a chart appears in markdown

```plot view=monthly_revenue
Plot.barY(data, { x: "month", y: "revenue" })
```

Three things happen:

1. PlotPress runs monthly_revenue against the dashboard’s default connection.
2. The result rows become data inside the block body.
3. The expression’s return value is rendered. If it’s a single mark, PlotPress wraps it in Plot.plot({ marks: [...] }). To control margins, scales, color, etc., return a full plot config.

Defaults

Every chart inherits a small set of defaults so most blocks are one-liners:

Default	Value	Override
Width	parent width	width: NUMBER in the config
Height	240 px	height=NUMBER in the fence info, or height in the config
Margins	Plot’s own (varies by mark)	marginLeft, marginRight, etc.
Color scheme	Plot’s tableau10	color: { scheme: "viridis" }
Grid	off	y: { grid: true }, x: { grid: true }

Parameters

Plot’s full mark-option reference is at observablehq.com/plot. Every chart page below lists the most-used options — there are more, and the ones below are stable across Plot’s 0.6.x line.