Ventana software support forum

Yes, that kind of thing can be done. You can also use FIND ZERO for a more general solution to simultaneous problems. There's a sample model for each included in the Help system. Thank you. I modelled it with ALLOCATE AVAILABLE function. But still I want to know how to define priority dynamicly tha...

Hi, I would like to ask a question which is related to this post. I want to do dispatch of power plants with Vensim itself. Assume that I have 3 power plants with specific price(a1,a2,a3) and capacity(b1,b2,b3). They take part in one auction for satisfying the demand(D). Power plants will be sorted ...

The word "count" implies "stock". You can do something like the following: count = INTEG( counting, 0 ) counting = start of cycle/TIME STEP start of cycle = {logical flag - a function of your process} The trick is to avoid counting the same cycle in consecutive TIME STEPS, but i...

Hi,

I want to consider a maximum number of storage cycle for storage technology in my model. It means that a storage technology cannot exceed its maximum number of cycle. Do you have any suggestion how to model it in Venism.
*Whenever it is used it can be consider as a one cycle.
Best Regards

64 bit Vensim will have all the same functions as 32 bit Vensim. If you use external functions, you will need to re-compile these to create a 64 bit DLL before use. 64 bit version will not decrease running time (it will probably take longer to run). Do have any other suggestion for decreasing runni...

Wow - this is huge to run with such a fine time step - it's generating something like 200 billion floating point numbers. I think you probably need 64-bit, even with other strategies like using a savelist to reduce storage. What is this about? I have increased size of the model by adding more power...

tomfid wrote: ↑Wed Feb 20, 2019 4:07 pm You'll need the .c source code for the functions you're using.

Thank you. I have them.

Users\public\vensim\cfiles isn't part of the Vensim distribution - could you have received that from whoever wrote the code for the external function? Yes, your are right. This folder has been added to Vensim folder and I want to edit its external fucntion which are all in '.obj' format. Can I add ...

What I have to clarify is that, I want to edit one of user defined functions. The thing is that, I do not find its C cource in COMP path(C:\Users\Public\Vensim\COMP) or cfiles path(C:\Users\Public\Vensim\cfiles), although I just see its .obj foramt in cfiles path.

Do you already have an external function library? I have one 'venext.lib' in this folder( C:\Users\Public\Vensim\cfiles). My model already has its own external function and it works well. I just want to know how can I edit one of these external functions. If yes, you must have edited the C code in ...

Hi, As you know, the address of external function in Vensim is in C:\Users\Public\Vensim\cfiles\venext.dll. But in this folder all files are in machine code. I want to change some part of my external functions but I cannot access their C format in this folder? Do you know which file has to be change...

Can you give an example of what you are doing? For example, I had 380 power plants in last version of my model but as I added more power plants to it, it has 1700 power plants now(i define this power plants in subscripts). The thing is that I cannot add more more power plants in subscripts becasue ...

Hi,

Does vensim have limitation for the number of characters in subscripts? When I wanted to add more characters in subscripts, I noticed that I cananot do it because it is impossible to add more than a fixed number of characters.
Do you have any suggestion for adding more characters?

Best Regards

Administrator wrote: ↑Sat Jan 26, 2019 3:40 pm It's hard to see anything on that image. What is "min cost flows"? And where does the cursor end up when you click ok?

I solved it. The problem was related to the compiler. Vensim had lost its connection to compiler, as a result, I could not change its text mode to sketch mode.

Administrator wrote: ↑Sat Jan 26, 2019 3:19 pm Can you share the syntax error?

And do you save your models in Dropbox/OneDrive/Google drive?

I get attached error. No I do save it in Dropbox/OneDrive/Google drive.

Hi,
I closed my model yesterday without any problem, but when I want to open it today it is text mode. When I want to change its mode from text to sketch I get this error: "Syntax error". Can you help me how to fix this problem.
Best Regards

Hi,
I have licence of DSS version(32 bit). How can I increase it to 64 bit?
Best Regards

Wow - this is huge to run with such a fine time step - it's generating something like 200 billion floating point numbers. I think you probably need 64-bit, even with other strategies like using a savelist to reduce storage. What is this about? I am using a savelist with 100 variables in its list. D...

tomfid wrote: ↑Sat Jan 05, 2019 6:54 pm How big is the model? (You can find the equation counts on the Model>Settings>Info tab.)

One option would be to switch to the 64-bit version.

Attached please find my model info.

Hi,

My model has 73249 time steps and when I run it, I get this error at different time steps:
"Not enough memory-decrease lenght or increase SAVEPER"

As it occures at different time steps I would like to ask you what is your suggestion for fixing it.

Best Regards,

Hi There are two difficulties in your formulation. The first is the correct use of the vector elm map and the possibility to use a simpler formula as explained in the link above or eventually the vector select explained by Tom. And once you are able to use a simpler formulation of the vector elm ma...

Can you upload your model? I did not realise that "hour of day" is a subscript. It really helps us to help you if you can upload things so we can see exactly what you are doing. Unfortunately, I cannot upload the model. However, I have attached the graph and formula of respective part. As...

Hi Avoid using the vector elm map function go to https://www.ventanasystems.co.uk/forum/viewtopic.php?f=2&t=3192&p=22055&hilit=vector+elm+map#p22055 It is good too setting the use stricte testing in the model<settings<units equiv window Regards. JJ Thanks for the help. Can you help me h...

I'd start by simplifying things. First of all create a new parameter that is parameter 1 = hour of year/Hour unit+EndUse Region-1-1 and one that is parameter 2 = Hours per Year/Hour unit*year unit Now a 3rd parameter = MODULO(parameter 1,parameter 2) And see what the value of this is. My guess is t...

Hi, I have one constant variable in the model as ‘Wind production as Fraction of Peak’ which it has two subscripts ( day of year ,hour of day). This variable is used in another variable called ‘wind onshore production this hour’ which its formula is as follows: Wind onshore production this hour[Endu...