This short writing introduces to you a small program called DiaGraph, which might be useful to you if you are a LaTeX user and are feeling some difficulty or inconvenience in drawing a block diagram with it. The program is a kind of preprocessor, which generates the LaTeX code for the block diagram that you have in your mind, given its description in terms of its own language. I hope that the language is simple and friendly enough so that everyone can get accustomed to it within a few hours or less. As one of the authors of the program, I would be happy if you could enjoy it.
DiaGraph generates only a picture environment of LaTeX; you must either insert the resulting output file into your manuscript manually, or \input or \include it, usually inside a figure environment. To use the program, no knowledge about the picture environment is prerequisite, but having some knowledge about it would be helpful. The only new LaTeX command that you might have to learn is \setlength; see Section 4 for more details.