XGED
X Window Graph Editor

XGED is a C program which implements an X Window based Graph Editor.

XGED can read in an abstract mathematical graph, display the nodes and edges, and allow the user to edit the information. It is also possible to display an animation, in which a sequence of graph images are displayed.

XGED is a version of the GED graph editor developed as part of the SPREMB project.

The main difference from previous versions is the support of animation. This has necessitated a new format for data files. The new file format is a "stream" of CGOs, that is, a list of CGOs instead of a single CGO. Each CGO in the stream is a frame of an animation. The CGOs in the list are separated by the "#" symbol; thus the new format is:

        CGO_1
        #
        CGO_2
        #
        CGO_3
        #
        ......
        ......
        ......
        CGO_k
      

The command read reads a file in the above format, and displays the stream

        CGO_1
        CGO_2
        ...
        CGO_k
      

The command write writes the graph in the workspace in CGO format.

The filter command behaves almost exactly as with previous versions: it passes the workspace to the nominated program, and reads the output of the program. However, note that the output of the program may be a stream as above; thus the filter may produce an animation. The filter command can be used with filters from previous versions; in this case, there is no animation.

The user can manually create a stream of CGOs for animation using direct manipulation and the filter command, as follows.

1. Type "cat >> test.animation" into the filter box.
2. Modify the current graph by adding or deleting nodes or edges, or moving nodes, to form a new graph.
3. Click the command filter. A CGO corresponding to the new graph will be appended to the file "test.animation".
4. Repeat steps (2) and (3) until the animation is complete.
5. Use the command read to view the animation "test.animation".

Languages:

XGED is available in a C version.

Related Data and Programs:

GRF is a data directory which contains a description of the GRF format and some examples.

GRF_IO is a FORTRAN90 library for reading and writing GRF files.

GRF_TO_EPS is a FORTRAN90 library which can make an encapsulated PostScript image of a GRF file.

X_WINDOW C++ programs which demonstrates some simple uses of the X Window library.

X_WINDOW_DISPLAY, a discussion of the issues involved when an X Window program on a remote machine needs to know how to get graphics information back to your local display.

XFIRES is a C program which simulates the occurrence of fires in a forest, and displays the status of the forest using X Windows.

XISING is a C program which simulates the variation in ferromagnetism in a material, displaying the results using X Windows.

XWAVES is a C program which simulates the behavior of solution of certain forms of the wave equation, displaying the results using X Windows.

Reference:

1. Peter Eades, Ian Fogg, David Kelly,
   SPREMB: A System for Developing Graph Algorithms,
   Congressus Numerantium,
   Volume 66, December 1988.

Source Code:

• xged.csh commands to compile, link and load the source code;
• drawing.c;
• drawing.h;
• drawingp.h;
• embed_ops.c;
• embed_ops.h;
• file_ops.c;
• file_ops.h;
• ged.c;
• ged.h;
• mode_ops.c;
• mode_ops.h;
• tool_static.h;
• view_hand.c;
• view_hand.h;

You can go up one level to the C source codes.