Ventana software support forum

I'll look into this today. I'll reply once I have some more information for you.

Tony.

Look for SIMULATE>RUNNAME in the help system, this will allow you to change the results file name.

Tony.

Yes.

Search the help system for SIMULATEBASED, it has all the information you need.

Tony.

What was the problem you couldn't work out? There is sample external function code that ships with Vensim. Search for the files VENEXT.DEF VENEXT.C VENEXT6.DSP VENEXT6.DSW VENEXT6.DSW is a Microsoft Visual Studio workspace. Open it and build the DLL. VENEXT.C is commented to show what to do to build...

If the text file does change every time step, you will need to write some external functions to do this.

Does the text file change every time step?

There is a section in the Vensim documentation that should help you, search for "Importing Data".

It might also help if you show us the format of the data you want to import. There is not much we can recommend/suggest if we cannot see what you are trying to do.

Tony.

Hello, You haven't really given us much information to go on. Have a read of http://www.ventanasystems.co.uk/forum/viewtopic.php?f=2&t=4391 and then re-post with a bit more detail and I'm sure someone will be able to help. There have also been many discussions regarding this, have a look through...

If you just want to save all the model sketches, just use a PDF printer (I use PDF995, search Google for it).

If you want to export all sketches to Word, you will need to select everything on each sketch, then copy/paste to Word.

What version of Vensim are you using? And what operating system?

Follow the instructions in the help system and it works fine.

subsc : (sub1-sub3)

SAMPLING AT TIME[subsc] = TABBED ARRAY ( 24 26 27 )

Personally I don't see any merit in discussing DT at all. As long as it is chosen based on the guidelines then it only becomes relevant when DT is too large. For me it is far more important to make sure models are dimensionally correct. It seems a lot of model builders see this as an optional step. ...

a) Is this a known issue or am I missing something? No, it's not a known issue. Can you post the settings you are using to publish and we can see what options you have ticked? b) If I am reading in data from spreadsheet files in my model will I have to include those as well and if yes can I just 'a...

Now, what I want is to save the changes made in datagridview values and put these new values in a .vdf file. I know how to do it with excel (first save changes in worksheets and then use xls2vdf command). But how do I do it without excel. Do I need to create a new .Tab, .Dat or .txt file from my da...

The modeller has just changed the colour of the arrow.

Try to work with vensim_get_vals. This probably will not work. tpoints1 = Unmanged.vensim_get_data("base1.vdf", "population", "Time", rval, tval, maxpoints(500)) Try the following (I'm writing this from memory so the syntax might not be quite correct). Dim tval() As Sin...

Can you list the code you are using and I should be able to correct the calls.

You will need to store the values in a level, remove them after one year (use a DELAY FIXED for this) and divide by 12 (or the delay time if in months). You could also use a queue fifo to store the values. This would also give you the ability to calculate averages over a different time period than a...

Just a note (as I don't recall seeing it mentioned above). Straight from the Vensim documentation "TIME STEP should be smaller than 1/3 of the shortest time constant in the model (not applicable with automatic step size adjustment in Runge-Kutta integration)." "TIME STEP should be sma...

Nobody has reported anything similar.

What OS are you using, and what version of Vensim?

I'll try and answer some of your questions. 1. For one thing I am still at a loss with regardt to the usage of reference modes in packaged models. You guys sure have thought of something when putting reference modes into Vensim, haven't you? - The ease of creating scenarios etc. (naming and saving t...

Not with normal graphs. You will need to use custom graphs to do this. But there may be a shortcut that helps. Select the first parameter you want to display, hold the shift key down and select the 2nd/2nd/nth. Now click the graph tool. It should display all of them on the same graph. If you right c...

You don't specify the loops the function has, you specify how many subscript ranges it is going to be responsible for calculating. In C/C++ you can do anything you want to. For example, if you have x[sub] = SOMEFUNCTION_EG_COS(a[sub]) SOMEFUNCTION_EG_COS is computing COS, the function needs to be ca...

You can use the following.

DRIVING data held backward :HOLD BACKWARD: := DRIVING data var as reference mode

This works in the same way as the lookup.

I can only assume that the "-1" is causing problems. I'll ask our programmer to take a closer look.

Tony.

Email me at vensim@vensim.com with your serial number.

Tony.