Sort equations by computational order

Mortengryning · Post by **Mortengryning** » Fri Sep 17, 2010 11:28 am

Hello all.

I'm using Vensime PLE for a student project. In that project I need to see equations in the order they are computed.

When I open up the documentation tool (DOC) i can't seem to find a way to access the documentation options dialog, where I can select the option of computation ordering.

In the manual for PLE, It states "In addition to the standard options, the Document tool allows you to select what information you want to see for a variable, and in what format."

How do I access the documentation tool options, so i get order the equations in the order of computation?

Kind regards
Morten

rdudley · Post by **rdudley** » Fri Sep 17, 2010 1:07 pm

I don't think you have those options with the PLE version.

Mortengryning · Post by **Mortengryning** » Fri Sep 17, 2010 1:21 pm

Do you know in which version this functionality is available?

LAUJJL · Post by **LAUJJL** » Fri Sep 17, 2010 2:12 pm

There is an option in Vensim Dss in the document tool, ordering check comp and the document tool lists the variable as they are computed, constants included. It starts often with the levels whose initialisation is a value. One must be conscious that in Vensim the order is not controlled by the modeller but by the software that works with the causal paradigm. Vensim orders the calculation using causality. I bothered about the order of calculation when I first used Vensim years ago, but after a while I realised that there is in fact no need to bother about it especially if you work properly using influence diagrams prior to building any model. But it still may be useful in special cases or if you need to understand how the calculations are done if you are new to SD.
Regards.
JJ

bob@vensim.com · Post by **bob@vensim.com** » Sat Sep 18, 2010 10:18 am

Options for the document tool are only available in Vensim Professional and DSS.

If it is a small model, you can easily determine this by going through the variables alphabetically and looking at causes (follow the cause tree till all precedents are computed or constant then put those variables in the computation tree). There is a separate ordering for active and initial computations. There is a section on "Computational Sequence" in Chapter 2 of the Reference Manual that describes this.