About link annotations

A link (`@') annotation permits external data to be associated with a specific time (and, optionally, a specific signal) in a record. To make link annotations visually distinctive, WAVE displays them in the color used for signals rather than that used for other annotations, and it underlines them. The aux field of a link annotation contains a URL (uniform resource locator) that points to the external data, and an optional description displayed by WAVE at the location of the annotation. (If the description is missing, WAVE displays the URL name.)

To view the external data associated with a link annotation, select it and then press \Ovalbox{\small\sf Return} (or \Ovalbox{\small\sf Enter}). WAVE then directs your web browser to display the data specified by the URL. (If your web browser is not running, WAVE starts it.) By default, WAVE uses Mozilla. To configure WAVE to use a different browser, see WAVE and the Web.

If the URL string does not contain a protocol:// prefix (where protocol is typically http or ftp), WAVE assumes that the URL refers to a file located somewhere in your WFDB path. In this case, WAVE finds the file if possible, and attaches the necessary path information to the beginning of the URL before directing your web browser to display the associated data.

WAVE does not include built-in facilities for editing external data. You may insert and edit link annotations themselves, however, using the normal annotation editing facilities of WAVE . To create a link annotation, select `@' from the Type menu of the Annotation Template, and enter the URL in the Text (aux) field. If you wish to supply a description to be displayed by WAVE in place of the URL, enter it after the URL, separating it from the URL with a space character. The current URL (i.e., the one associated with the most recently selected link annotation) can be passed by WAVE to an external program such as a web browser or an HTML editor via the $URL menu variable (see the comments in WAVE 's menu file for details).

George B. Moody (george@mit.edu)