Why is a boxed variable always assumed to be a level?

[gwr]

In Vensim if a variable is drawn with a box Vensim will automatically assume that it is a level. Why so?

There are two sketch tools, one for auxiliaries/constants and one for boxed vars/levels. Why not use that information and "trust" the modeler that he knew why he wanted an auxiliary/constant to appear boxed? The way a variable is drawn (sketch information) and its internal meaning in the model (e.g. level, aux etc.) are after all separate and independent features. There are good reasons to represent an exogenous constant as a boxed variable without being a level with in- and outflows. A smooth is often represented as a boxed variable without being a level in the equation editor.

Kind regards,

Guido

[Administrator]

We've got to assume a box is some sort of variable, and the norm for a box in a SD is a level. Simple as that. If we assumed it was an auxiliary, someone else would ask why isn't it a level.

[gwr]

Still beats me since the "box" does not fall from empty space on a sketch and then has to be interpreted but is put there by the modeler who has used the sketch tool for auxiliaries/constants to do that (on purpose!). Since Vensim does "know" which tool is used when a variable is placed and since the software does allow a boxed variable to be an auxiliary/constant I would suggest to change that feature. Especially since you cannot simple copy formats easily with something like a paint brush (like it is done in MS Office) it would be nice if the modeler is "trusted" a bit more

Kind regards,

Guido

[tomfid]

So what you're after is a way to have a box tool on the toolbar, that defaults to something other than a level?

I think you'll find that Vensim trusts the modeler a lot more than the competition, at least in the SD space. Most packages impose stricter correspondence between diagram and equation.

Have you discovered that you can edit the variable shape by right-clicking, and for multiple selected variables by using the shape control button in the bottom toolbar?

Tom

[gwr]

Tom,

thank. Ok, the bottom menu is a partial solution since I can put an auxiliary on the sketch, select 'box' down there and still find it to be an auxiliary/constant in the equation editor. What I wanted is that my choice of default shape for the sketch tool "auxiliary/constant" will not predetermine the initial interpretation by the equation editor. Maybe it would be clearer if the sketch tool for "boxed variable" would be considered as the "level sketch tool" - e.g. have these tools determine the initial interpretation and not the shape ?

What I am missing in the bottom menu is a tool to change to inner color of a box (e.g. its background/filling) since I do like to work with different colors in my model. Could you put that up on the wishlist or prove me blind for not seeing the tool in case there is one

Guido

[Administrator]

What I am missing in the bottom menu is a tool to change to inner color of a box (e.g. its background/filling) since I do like to work with different colors in my model. Could you put that up on the wishlist or prove me blind for not seeing the tool in case there is on

I'll put it on the wishlist.

[gwr]

Great! ... and the cumulated effect of all those 'minor' improvements will be a greatly reduced switching probability for all Vensim users

Keep it up, Guido.