Re: [Mtt-developers] Re: Legacy examples & components.

[Geraint <geraint geraintpaulbevan freeserve co uk>]

Lars Clausen <lrclause@cs.uiuc.edu> writes:

> On Thu, 28 Nov 2002, Peter Gawthrop wrote:
> > Hi Dave & Geraint,
> > 
> > just to say that it is important to retain fig for the time being, and
> > indeed allow systems with components with either fig and dia
> > representation -- I don't see a problem with this, do you?
> 
> We have no intention of removing the fig import and export components from
> Dia, but there are things in Dia that cannot be expressed in Fig and vice
> versa, so it cannot be an underlying file format.
> 
> -Lars
> 

Hi Lars,

as things stand at the moment, MTT works with bond graphs built with Xfig and looks to be well on the way to working with bond graphs built with Dia. The way that MTT works is to transform models between various representations, often for use with different tools or languages, by way of other intermediate representations.

I don't think that we will have any problem adapting MTT to work equally well with models built with either of the drawing packages - we just need to define a route to a common representation from each format. This common representation (or set of representations) must contain the information necessary to generate equations, but it does not have to contain the graphical information. Therefore, I don't think that importing/exporting drawings between Xfig and Dia will really be an issue for us. The problem that we face is getting MTT to work with models created with one tool that contain sub-models built with the other.

As bond graphs are hierarchical, it will be necessary for us to be able to generate equations from models such as these, however I don't expect that we will attempt to do this by converting (or importing) models from one format to the other, or by defining a common graphical format. Rather, we should be able to accomplish our goal by ensuring that MTT can work at each level of the hierarchy in whichever format the model happens to have been drawn in.

By the way, thank you for being so receptive to Dave's suggestions for improvements to Dia to help with the integration with MTT.

/Geraint.