Other de Bruijn diagrams
Having entered the de Bruijn submenu by typing d in the main menu, the de Bruijn screen will appear, having the general form of Figure 9. The left hand side of the screen contains an option menu, the right hand side a polygon representing the full de Bruijn diagram. Subdiagrams are shown by altering the colors of the lines. Unfortunately, the diagrams are usually too congested to be of any use.
- 1,2,... - generates a de Bruijn diagram of n stages
- a,b,c,... - shows cyclic counterimages
- A,B,C,... - shows all counterimages
- other letters - show (p,d) cycles
- +,- - selects the color palette
- ?,/ - clears screen, shows menu
- CARRIAGE RETURN - exits
To obtain information from the de Bruijn submenu will probably require the use of pencil and paper, or the use of the screen dump program. Although the program lists all the links in the de Bruijn diagram, the ring diagram is generally too cluttered to use directly from the screen and should be redrawn. Usually the resulting diagram can be further simplified, often it contains many redundant loops. Used casually, it still shows whether there will be many or few periods of a given type.
Harold V. McIntosh
E-mail:mcintosh@servidor.unam.mx