Observable JS is a set of enhancements to vanilla JavaScript created by Mike Bostock (also the author of D3). Observable JS is distinguished by its reactive runtime, which is especially well suited for interactive data exploration and analysis.

Learn more about using Observable JS with Quarto in the articles on Interactive Documents with Observable JS.

## Overview

Cell options affect the execution and output of executable code blocks. They are specified within comments at the top of a block. For example:

{ojs}
#| label: fig-polar
#| echo: false
#| fig-cap: "A line plot on a polar axis"


## Attributes

 label Unique label for code cell. Used when other code needs to refer to the cell (e.g. for cross references fig-samples or tbl-summary) classes Classes to apply to cell container

## Code Output

 eval Evaluate code cells (if false just echos the code into output). echo Include cell source code in rendered output. Specify fenced to include the cell delimiter as part of the output. code-fold Collapse code into an HTML 
tag so the user can display it on-demand. Specify show to have the code initiallly visible. code-summary Summary text to use for code blocks collapsed using code-fold code-overflow Choose whether to scroll or wrap when code lines are too wide for their container. code-line-numbers Include line numbers in code block output. lst-label Unique label for code listing (used in cross references) lst-cap Caption for code listing

## Cell Output

 output Include the results of executing the code in the output (specify asis to treat output as raw markdown with no enclosing containers). warning Including warnings in rendered output. error Include errors in the output (note that this implies that errors executing code will not halt processing of the document). include Catch all for preventing any output (code or results) from being included in output. panel Panel type for cell output (tabset, input, sidebar, fill, center)

## Figures

 fig-cap Figure caption fig-subcap Figure subcaptions fig-link Hyperlink target for the figure fig-align Horizontal alignment for the figure (default, left, right, or center) fig-alt Alternative text to be used in the alt attribute of HTML images. fig-env LaTeX environment for figure output fig-pos LaTeX figure position arrangement to be used in \begin{figure}[]. fig-scap A short caption (only used in LaTeX output). A short caption is inserted in \caption[], and usually displayed in the “List of Figures” of a PDF document.

## Tables

 tbl-cap Table caption tbl-subcap Table subcaptions

## Panel Layout

 layout 2d-array of widths where the first dimension specifies columns and the second rows. For example, to layout the first two output blocks side-by-side on the top with the third block spanning the full width below, use [[3,3], [1]]. Use negative values to create margin. For example, to create space between the output blocks in the top row of the previous example, use [[3,-1, 3], [1]]. layout-ncol Layout output blocks into columns layout-nrow Layout output blocks into rows layout-align Horizontal alignment for layout content (default, left, right, or center) layout-valign Vertical alignment for layout content (default, top, center, or bottom)

## Page Columns

 column Page column for output fig-column Page column for figure output tbl-column Page column for table output cap-location Where to place figure and table captions (top, bottom, or margin) fig-cap-location Where to place figure captions (top, bottom, or margin) tbl-cap-location Where to place table captions (top, bottom, or margin)