Re: Bond Graph modeling with Dia

[David Hoover <david hoover epfl ch>]

> I am in hurry but I am wondering about your requirements and I am also
> wondering about the "Civil" (Civil Engineering presumably, damn i need to
> get busy on the documentation) Sheet.
> I have so far copied the first sheet of Shapes from Visio from the
> "Process Engineering" General category but there are about 5 sheets i have
> not yet begun to hack the XML or draw the icons.
>
> My question, Is this is all more or less related?  If so i hope we can be
> careful to avoid redundant work, even if I probably have already redone
> a few shapes that are very similar to those in the Civil Sheet.
>  
There would be no overlap, because bond graph modeling is a completely 
different approach to the classic circuit diagram approach.  Unlike the 
classic approach, bond graph modeling permits direct computer simulation 
and equation generation from multi-domain problems.  Example:  A 
loudspeaker cannot be modeled with an electrical circuit diagram (from 
'Circuits'), because it contains moving mechanical parts.  It also 
cannot be modeled with the classic mechanical engineering diagrams with 
dampers and inertias, because it contains electrical components.  If you 
try to combine the two, you can get something that looks nice, but no 
computer program could ever interpret the diagram and know how to 
simulate it or derive equations.  Bond graphs allow you to model this 
type of system, and automatically generate computer simulations and 
system equations.

Generally, you could write a bond graph on one layer of the diagram. 
The simulation environment would interpret the xml code of that layer. 
You then might annotate the bond graph with classical 
mechanical/electrical symbols on a different layer, just as a kind of 
'comment' for human readers.  The is the approach used by the mtt tools, 
but with the unfortunate choice of xfig as the diagram editor.

If I can get text to work in plain old shape objects, by editing the 
xml, I will make the objects.  I imagine that the 
'distance-from-a-point' object method that Lars mentioned would not 
detect this text.  Am I right?

> Please do setup a bugzilla entry to help us to keep track of your
> requirements for Bond Diagrams.  (put it under general, shapes is more
> about requesting specific shapes for me to draw).

I'll get on that right away.

Dave.