Search found 4568 matches

by Administrator
Tue Sep 25, 2012 8:16 am
Forum: System Dynamics Discussion
Topic: From steady-state to dynamic model
Replies: 6
Views: 6983

Re: From steady-state to dynamic model

I cannot really comment at all on the model. For example "tconst" means nothing to me. I'm certainly no expert in the chemicals industry.

It's far better to ask specific questions if you are having problems rather than asking for general comments.
by Administrator
Mon Sep 24, 2012 3:11 pm
Forum: Vensim
Topic: add a delay between inflow and outflow
Replies: 2
Views: 2041

Re: add a delay between inflow and outflow

You've actually already got a delay in there (fraction of buyer is measured in percent per week to buy). You might take a look at http://models.metasd.com/delay-sandbox/ It might also be better if you give a brief description of what you are trying to model. Looking at what you have, I'd start with ...
by Administrator
Fri Sep 21, 2012 8:25 am
Forum: Vensim
Topic: SynthSim
Replies: 4
Views: 3037

Re: SynthSim

Hello Eddie, I got the following to work. Use TOOL,"GR1",24,20,46,46,,,CUSTOM>test instead of the WIPTOOL you had before. COMMAND,"",0,0,0,0,,,SPECIAL>LOADRUN|current.vdf COMMAND,"",0,0,0,0,,,SPECIAL>READCUSTOM|test.vgd COMMAND,"",0,0,0,0,,,SPECIAL>SETWBITEM|S...
by Administrator
Wed Sep 19, 2012 11:25 am
Forum: Vensim
Topic: Time look up and variable look up
Replies: 21
Views: 11637

Re: Time look up and variable look up

1. I want to use data for creating look up which will be input of a variable or output of a variable. such as last 52 weeks production, sales, demand, supply etc. See http://www.vensim.com/documentation/index.html?fn_get_xls_data.htm There is an example model as well that you can look at. 2. Yes, s...
by Administrator
Wed Sep 19, 2012 8:52 am
Forum: System Dynamics Discussion
Topic: Suitable formula
Replies: 3
Views: 4604

Re: Suitable formula

Have a look at the model "AGECHAIN.MDL". If you are running Windows 7, it should be in C:\Users\Public\Vensim\help\models\Sample\EXTRA\ or http://www.vensim.com/documentation/Models/Sample/EXTRA/AGECHAIN.MDL This will be a good model to start with. Change the variable names so that they ar...
by Administrator
Wed Sep 19, 2012 8:29 am
Forum: Vensim
Topic: Time look up and variable look up
Replies: 21
Views: 11637

Re: Time look up and variable look up

What format is your data in? Is it in Excel, text files or something else? Subscripts: These allow you to replicate model structure quickly. For example, if you have a model that looks at bank balance, you could add subscripts to this so that it modelled many bank balances. The following section in ...
by Administrator
Wed Sep 19, 2012 8:23 am
Forum: Vensim
Topic: Problem with Arrows
Replies: 2
Views: 1845

Re: Problem with Arrows

I think you must have some model structure hidden.

Click View->Show Hidden->All.
by Administrator
Tue Sep 18, 2012 10:18 am
Forum: Vensim
Topic: Why is a boxed variable always assumed to be a level?
Replies: 6
Views: 4194

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

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.
by Administrator
Tue Sep 18, 2012 9:15 am
Forum: Vensim
Topic: Time look up and variable look up
Replies: 21
Views: 11637

Re: Time look up and variable look up

as you suggest me to practice data variable. could you please refer a simple data variable model where you called data from excel or some other places to run a model? please define how to use or locate input/output or X/Y variable if possible. It's all in the help system, see http://www.vensim.com/...
by Administrator
Mon Sep 17, 2012 12:44 pm
Forum: Vensim
Topic: Time look up and variable look up
Replies: 21
Views: 11637

Re: Time look up and variable look up

I have seen some model that they did not use any time variable. is it possible to continue the same purpose without giving input of time variable? Yes My second question, if I use "time to adjust" variable unit as "week" and will divide with an auxiliary variable which is unit/w...
by Administrator
Mon Sep 17, 2012 12:41 pm
Forum: Vensim
Topic: Why is a boxed variable always assumed to be a level?
Replies: 6
Views: 4194

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

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.
by Administrator
Mon Sep 17, 2012 9:06 am
Forum: Vensim
Topic: Time look up and variable look up
Replies: 21
Views: 11637

Re: Time look up and variable look up

You are nearly there with the lookups. See the attached model.

I've created a "lookup" called "Sales depot 1 table".

Then I've modified your "Sales depot 1" parameter so that it is now

Code: Select all

Sales depot 1 = Sales depot 1 table ( time )
by Administrator
Mon Sep 17, 2012 9:01 am
Forum: Vensim
Topic: subscript help
Replies: 2
Views: 1960

Re: subscript help

Welcome to the forum. There are two examples in the Vensim help system that should help. See http://www.vensim.com/documentation/index.html?models_extra.htm If you are running Windows 7, they should be in C:\Users\Public\Vensim\help\models\Sample\EXTRA Have a look and let us know if they do what you...
by Administrator
Mon Sep 17, 2012 8:17 am
Forum: System Dynamics Discussion
Topic: From steady-state to dynamic model
Replies: 6
Views: 6983

Re: From steady-state to dynamic model

Have you read the PLE tutorial at
http://www.public.asu.edu/~kirkwood/sysdyn/VenPLE.pdf

This is a really good introduction to dynamic modelling. I would start with the tutorial before going any further.
by Administrator
Fri Sep 14, 2012 2:00 pm
Forum: Vensim
Topic: PLE V6.0a unable to change equation editor font
Replies: 5
Views: 3636

Re: PLE V6.0a unable to change equation editor font

I cannot change the colour either (it is always black). But I can change the fonts without any problem. I did try selecting a 72 point font and that didn't work, but selecting 16 point font was fine. Is it just the size/colour of the font that is causing problems? Can you select something like Times...
by Administrator
Thu Sep 13, 2012 6:00 pm
Forum: Vensim
Topic: PLE V6.0a unable to change equation editor font
Replies: 5
Views: 3636

Re: PLE V6.0a unable to change equation editor font

I can change it on my PLE. Options->Options then click the equation editor font button.

What happens when you do this?
by Administrator
Thu Sep 13, 2012 9:38 am
Forum: Welcome and General Information
Topic: Vensim 6.0A released.
Replies: 0
Views: 16989

Vensim 6.0A released.

Vensim 6.0a is now available for download or purchase in the Vensim store. Release Version 6.0a includes fixes for several problems introduced with new features in Version 6.0. These include: - Equation Editor - Icons - Optimization - Excel import Equation Editor Data Equations: The new equation edi...
by Administrator
Wed Sep 12, 2012 12:23 pm
Forum: Vensim
Topic: unit conversion
Replies: 23
Views: 22622

Re: unit conversion

Qs: 1. why do not you use rate variable or bulb as you used auxiliary? Is there any particular reason behind it? I was trying to do this quickly. Q2. How can I add capacity and target variable? I want to set a target production which might hamper with existing capacity; at the same time capacity wi...
by Administrator
Wed Sep 12, 2012 9:11 am
Forum: Vensim
Topic: unit conversion
Replies: 23
Views: 22622

Re: unit conversion

I've attached a model that will hopefully help you a little.
by Administrator
Wed Sep 12, 2012 8:47 am
Forum: Vensim
Topic: How to use String Vars in a Macro?
Replies: 8
Views: 5215

Re: How to use String Vars in a Macro?

thanks for the responses which unfortunately are not solving my problem: I wanted to hide 'unnecessary' model structure and having to include string vars does do the exact opposite. My preference is to see as much structure as possible. I went through a "painful" model conversion recently...
by Administrator
Tue Sep 11, 2012 3:43 pm
Forum: Vensim
Topic: Hotlink Example
Replies: 1
Views: 1844

Re: Hotlink Example

If you want to export to Excel every time step, you will need to write an external function. There are some helper functions for you to do this, see http://www.vensim.com/documentation/index.html?25885.htm. The other alternative is to run the simulation from Excel using the Vensim DLL. This way you ...
by Administrator
Tue Sep 11, 2012 8:09 am
Forum: Vensim
Topic: unit conversion
Replies: 23
Views: 22622

Re: unit conversion

ok, start with "FARM IN RATE". What is this, and what is it measured in?
by Administrator
Mon Sep 10, 2012 7:16 pm
Forum: Vensim
Topic: How to use String Vars in a Macro?
Replies: 8
Views: 5215

Re: How to use String Vars in a Macro?

I've just tried your macro and it works for me.

Have you made the relevant parameters that are passed to the macro string variables?
by Administrator
Fri Sep 07, 2012 9:20 am
Forum: Vensim
Topic: unit conversion
Replies: 23
Views: 22622

Re: unit conversion

It might be a good idea if you did the PLE tutorial at
http://www.public.asu.edu/~kirkwood/sysdyn/VenPLE.pdf

Page 13 mentions what time step is.

More information is also at
http://www.vensim.com/documentation/ind ... sdates.htm

Hope this helps.

Tony.
by Administrator
Fri Sep 07, 2012 9:17 am
Forum: Vensim
Topic: vendll
Replies: 2
Views: 1606

Re: vendll

The c# example that ships with Vensim has some calls to vensim_get_varattrib. Have you tried that?