GLAD

1. Name:
   GLAD (Generic LAyout for Directed Graphs)

2. Source:
   University of California, Irvine. Arcadia Project.

3. Brief description:
   GLAD is an Ada generic package providing static or dynamic layout facilities for directed graphs. Given a description of a graph, it provides coordinate sets for the positioning of elements of a graph on an arbitrary cartesian coordinate plane. Layout coordinates can be provided for either a complete graph description or incremental, dynamic updates to a graph structure. This allows dynamic graph editing, including addition and deletion of any graph element. Provisions are available to provide minimum disturbance of a current layout description when edit updates to the graph structure are made. The system does not impose any particular user interface on the instantiator, and does not assume anything about the actual display of a graph, except the location of graph elements, which it provides. Facilities are provided for balancing the layout structure. If order of graph nodes is not important, a facility to reduce edge crossings is also available.

4. Evaluation against applicable general dimensions:
   1. Availability: commercial/licensed/public domain
      Public domain.

   2. Cost:
      Public domain. ftp://liege.ics.uci.edu/pub/arcadia/glad

   3. Degree of support/maturity/testing/usage:
      An early version of the system that did not allow deletion of graph elements received wide use within the Arcadia consortium using Chiron and Interviews as user interfaces. A preliminary version of the latest system is also being used by a number of Chiron artists within the consortium.

   4. Speed:
      GLAD's performance has yet to be calculated, but is largely dependent on the actual operations performed and the size of the graph being manipulated. Instantiation within a Chiron artist gives reasonable interactive performance for graphs with fewer than one hundred nodes.

   5. Computing platforms:
      Unix. Developed under SunAda version 1.1.

   6. Language compatibilities:
      Written as an Ada generic package.

   7. Footprint:
      1. Source: 1.6 kB

   8. Openness/integrability/source availability:
      GLAD is an Ada generic, and requires that an instantiator be able to provide the necessary information about a graph for layout through generic parameters.

   9. Extensibility:
      N/A.

   10. Pedigree: ARPA developed?
       Developed under ARPA grant number MDA972-91-J-1010

5. Contact persons:

   Craig Snider
   Department of Information and Computer Science
   University of California
   Irvine, CA 92717
   snider@ics.uci.edu
   (714) 824-7202
   (714) 824-4056 - fax

6. Pointers to literature, demos, etc.: N/A