eng_pikchr: Pikchr Code Engine for Knitr

In pikchr: R Wrapper for 'pikchr' (PIC) Diagram Language

Pikchr Code Engine for Knitr

Description

A custom knitr engine to render Pikchr diagrams as SVG (HTML output) or PNG (LaTeX, DOCX, and other non-HTML formats). Works with both RMarkdown and Quarto documents.

Usage

eng_pikchr(options)

Arguments

options

A list of chunk options from knitr.

Details

The eng_pikchr function allows you to use Pikchr code inside R Markdown and Quarto documents, rendering it as an image. It supports options like width, height, fontSize, fontFamily, and CSS classes to customize the output.

The engine automatically detects the output format. For HTML-based outputs (html, revealjs, slidy, etc.) the SVG is embedded inline. For non-HTML outputs (LaTeX/PDF, DOCX, EPUB, Typst, etc.) the SVG is converted to PNG via rsvg_png.

Value

Rendered output suitable for the target document format.

Chunk Options

Standard knitr options:

eval

Whether to evaluate the Pikchr code (default TRUE).

echo

Whether to display the code in the output (default TRUE).

fig.cap

Figure caption (supported in both HTML and non-HTML output).

fig.alt

Alternative text for accessibility (HTML only).

fig.align

Figure alignment: "left", "right", "center", or "default".

out.width

Output width for non-HTML formats (e.g., "80%").

dpi

Resolution for PNG conversion in non-HTML output (default 150).

Pikchr-specific options:

width

CSS width of the SVG (default from viewBox, e.g., "80%").

height

CSS height of the SVG (default "auto").

fontSize

Font size for the diagram (default "100%").

fontFamily

Font family for the diagram (default "Jost").

class

CSS class for the SVG element (default "pikchr").

css

Additional inline CSS styles for the SVG.

margin

CSS margin around the SVG (default "10px 0 10px 0").

See Also

pikchr, knit_engines

pikchr documentation built on Oct. 30, 2026, 1:07 a.m.