Draw a key as a box diagram

Draws a dimoose key top-down as an SVG picture, the way keys are often drawn on paper: each couplet is a blue box holding its question, its leads are blue boxes below it, and every lead either continues to the next couplet or ends in a green box naming the result. A result written as "Common name (Genus species)" is drawn on two lines with the scientific name in italics.

Usage

keyDiagram(key, file = NULL, images = TRUE, title = NULL)

Arguments

key

A dimoose key.

file

Optional file to write: .svg, or .png and .pdf when the 'rsvg' package is installed.

images

If TRUE, show a thumbnail in a result's box when the terminal lead names an image (Image column) that is embedded in the key's meta (see imageMeta()).

title

Heading drawn above the tree; by default the key's desc. Use NA for none.

Value

The SVG as a single string, invisibly when file is given.

Details

Thumbnails are shrunk to 112 pixels when the 'magick' package is installed, which keeps diagrams of keys with large photos small. When 'rgnparser' and its 'gnparser' program are installed, only text that parses as a scientific name is set in italics.

A couplet reached from more than one lead is drawn once, under the first of them; the other leads get a dashed line to it.

See also

exportWizard() for an interactive version of the key.

Examples

keyDiagram(arachnidaKey(), tempfile(fileext = ".svg"))