Internal layout of documents

The chapters of the books have a unique mapping to computer directories. Inside any chapter directory is a file with the text of the chapter and also several topic directories most of which build figures. A figure directory may build a single figure or several. Each of about 70 figure directories declares:

1.

that the figure is in the book PVI (or IEI),

2.

the chapter name,

3.

a list of figure names

4.

commands that prepare those figures, and

5.

that SEP definitions, compilation rules, and i-doc rules are to be included.

Besides the many figure directories are several directories that install executable programs which are used more globally in the book. Modern programming languages, especially C, facilitate the idea of variables being local, or global, or at intermediate stages. We are trying with partial success to segregate components of interactive documents in the same way. Logically, the subroutines described by a chapter should be files kept with the chapter, but at present they are gathered together for the whole book in a single library directory. When PVI is completed I will devote more energy to activating IEI and then the question will arise of how to handle parts that are common to the books. From a program maintenance view, there should never be duplication, which implies that a few chapters or appendices in each book should be identical or the books should be merged into a consistent whole.

We enhance the mechanisms of interactive documents in two ways, (1) in the L^ATEX author's environment, and (2) in the figure building file (cakefile). The L^ATEX environment invokes the figure building script (cakefile) but does so in only a standard way that we have chosen to be the command ``Change directory to chapter X, figure subdirectory Y, and invoke the system command `cake -DREADER figurename.idoc'''. From there control leaves the manuscript environment and passes to the figure making cakefile which may interpret it arbitrarily, and if it is ignored, control passes along to the default cake rule which now invokes the vplot display program leaving the reader with (theoretically) only color and zoom to adjust.