Ventana software support forum

Dear Tom/Administrator, I was wondering if there is any way in Venapp that keeps the constants' value fixed in different runs? I mean if I change the value of a constant at run1, for starting the run2 the constant value will be back to its default value; while I would like to do all of my runs with ...

Dear Tom, Administrator, I want to create a page in Venapp interface that allows the user to do a sensitivity analysis on any parameters that he wishes. Accordingly, I need to know how can I open the "Sensitivity Simulation Setup" window in Venapp by creating a button (or another way)? I l...

Dear Tom,

Thnaks so much for your answer. By using GET VDF DATA, I just could import just one varibale as 'varname' while my sensitivity analysis is consists of 34 runs (please find the attached file). Is there any way to import all outputs?

BR,

Dear Administrator,

Thanks for your reply. Because as the first step, I need to normalize all the sensitivity analysis data before processing. Hence, I need to import the sensitivity analysis data.

BR,

Dear Tom/Administrator,

I want to import the sensitivity analysis of one model into another model. The ordinary GET DIRECT DATA (XLS) commands, just import one variable, while in sensitivity analysis, I need to import different runs of sensitivity. Is it possible to do?

BR,

Dear Administrator,

Thanks for your reply. In fact, I expected that the results shifted to right side one by one year! because I used the Vector distribution by an increament of 1.

Dear Tom/Administrator, I want to do a sensitivity analysis on initial time! I am not sure such a work is possible or not because after running sensitivity, I got the results same as a simple run! In fact, I want to know if I defer the initial time one by one, what would be the results. Could you pl...

Dear Administrator,

Thanks for your reply.
Actually, I did not try it because I thought since emission rate is changing, the initial value of total emission would also change! However, now, I tried it and worked!
Thanks again.

Dear Tom, Administrator, I want to get the value of the first time of a flow and use it as the initial value of its level (please see the attached figure) i. e. I want to use the value of "Emission rate" at the first time as the initial value of "Total emission". Could you please...

Yes, it works. Thanks so much

Thanks for your reply. I have already read this part, but I mean "automatically" exporting some variables after finishing simulation. Creating a savelist needs manual process after finishing simulation, while I am looking for an "automatic" way for exporting and updating after ea...

Dear Tom, Administrator,

I just need to export the data of some variables from the model (and not all the run). Is there a way to do so?

BR,

Dear Tom, Administrator, I want to compare different runs from my model, but one of them has a significant difference from others to the extend that others are not visible(please see the attachement 1)! changing the scale of the axis is not also proper (please see the attachement 2). I want to know ...

Dear Tom, Administrator, I have read some articles aboput SD that their casual loop diagram is totally different from their stock and flow diagram! In casual loop they tried to draw a general descriptive relation between variables while in stock and flow, those variables are not mostly defined any m...

I just solved it by constituting Time i+1 via DELAY FIXED function by one unit. Afterward, I deducted the two variables and it works! However, is there another direct solution?

Dear Tom, Administrator, I want to make a comparision between two consecutive value by IF THEN ELSE function. Then, I need to take these values and compare. Somthing like the following example. IF THEN ELSE (value at Time i = value at Time i+1, 0, value at Time i+1 - value at Time i) Could you pleas...

Dear Tom, You mentioned that it is possible to do a sensitivity analysis on Seed by using a VECTOR function. However, in the "Sensitivity Simulation Setup" box in the software, there is also another "Noise Seed", which is by difault "1234"!!! Are these Seeds different? ...

Dear Tom, Administrator, I want to add a constant in a level from a specific time step to the end of simulation. Just like PULSE function, however, the initial time is conditional (when the first non-zero number will be resulted). For instance, consider the following level, constant and level + cons...

Thanks for your reply.
But is it possible to use LOOKUP (or any other function) for such problems? because we do not use equations in LOOKUP but just define a function.

Dear Tom, I want to model the safety issues in mining equipment usage in Vensim. Before it, I have just used from parameters that they have constant values and variables can be precisely determined by equations . However, in this case, I just have some descriptive issues which there is no equation a...

Dear Tomfid, Thanks so much for your answer. It was really helpful. I made the changes you explained and added this command: under quota cost = IF THEN ELSE(Total Blasting Production>=PPY, 0, -1000) . But, I have a question. I could reach to the optimized answer by choosing a weigh of -10000 for &qu...

Hi, I need to know if I want to optimize one parameter such that one of the stocks of the model reach to the a specific amount in an specific time. For example, I want to acquire that how many loaders I need that can reach to a production of 1,000,000 tons in the day of 365 (end of the year)? By the...

Hi,
I just wants to know how can "confedence Bounds" be interpreted in Vensim software? Generally, how they must be compare to the base run we have done?