load a dataset (run)

[irene]

Hello,
I have one problem: when i try to load a dataset (run) file (.vdf) from "open model" there is a message that vensim is unable to load it. What can i do?
thank you
irene

[Administrator]

Load it via the control panel instead (look for an icon on the top toolbar towards the right that has a picture a bit like a clock).

[irene]

I have already tried that!!

This is my problem: i have an .mdl file and i have developed several scenarios. these scenarios are saved as .vdf files. What i want is to call these scenarios while i am in the .mdl file. i have used the control panel>dataset they are there but when i select "load from" a separate window opens named "dataset to load" and then nothing happens!! it seems that the files are not recognized. i am very confused.... i will try again...
irene

[Administrator]

Can you email me one of the files you are trying to load and I'll see if there is a problem with it?

[tomfid]

What do you mean by "call" - are you trying to drive the model with data from the vdfs, or ...

The control panel only influences which runs display on graphs/tables etc. while you're looking at output. If you want to specify driving or calibration data, you need to use the Advanced tab of the Simulation Control dialog.

Tom

[irene]

Ok, I am sending you a simple model. I have 2 scenarios (travel time=1 week and travel time = 2 week). When i open the mdl file it automatically loads the last scenario. All i want is to open the first one that has been saved as a vdf and it is there when i choose "open model" but it cannot be loaded. i am sending you all.
thanks
irene

[tomfid]

I can open the model, load both datasets via the Datasets tab of the Control Panel, and view the output in graphs & tables, so I don't think there's anything wrong with the files.

Are you trying to open the .vdf as a model via File>Open Model... ? (That actually works in advanced versions, but you don't get a diagram, and there's no reason to do it unless you're trying to build a model for a dataset that originates from file data, and doesn't have a parent model.)

T

[irene]

thank you for your reply,

I know you can, i can do it too, what i want is not the diagrams. Now when i open a .mdl file i see the last version with its variables, in order to see the first version i have to change the variables and run the simulation again . and when i have more scenarios i have to alter the variables again and again if i want to make a change in any of them.
is there something i can do??

many many thanks.

[Administrator]

Have a look in the Vensim help at CIN files. These can be used to store the constants that are going to be used in a simulation.

Is this what you need to do?

What version of Vensim are you using?

[irene]

I am using version 5.11A. In help>vensim manuals i cannot find something about CIN files.
I want to be able to see the model for every scenario without having to change parameters all the time.
Irene

[tomfid]

If your datasets are loaded, like this:

controlPanel.PNG (11.95 KiB) Viewed 7766 times

You should see both trajectories, like this:

graph.PNG (16.65 KiB) Viewed 7766 times

Is that not what you're getting/wanting?

[irene]

No!!!
I now how to do that. Ok, i have a folder and there i have "model.mdl" file, a "Travel time=1week.vdf" (the scenario for the 1 week travel time) and a Travel time=2week.vdf (the scenario for the 2 week travel time). If i click on the "model.mdl" then it opens up and i see my model with the second scenario loaded. If i want to see the first scenario, then i have to alter "travel time", change the name to Travel time=1week and simulate. I want to avoid that. i want to look at these 3 files and say "i want to see Travel time=1week scenario", click on the "Travel time=1week.vdf" file and have it in front of me. Can i do that?, no diagrams, no comparisons, just the model with the stocks, flows, cause and effects, variables...

thank you for your help, my background is poor and i don't know how to describe my problem best.
irene

[tomfid]

Clearly I'm missing something. When you say, " i want to look at these 3 files and say "i want to see Travel time=1week scenario", click on the "Travel time=1week.vdf" file and have it in front of me. Can i do that?, no diagrams, no comparisons, just the model with the stocks, flows, cause and effects, variables... " do you mean:

You're in Windows Explorer or Mac Finder, looking at a directory containing the .mdl and two .vdfs. You want to (double)click on one of the .vdfs and have the model open with that .vdf already loaded, so that you can see the model structure (the stock-flow diagram) and the behavior for the selected scenario?

[irene]

yes yes yes...

[tomfid]

There isn't any way, from Finder/Explorer, to double-click a .vdf and have Vensim automatically load the .mdl that created it (that's actually a useful idea for the future, though it wouldn't work in all cases, because a .vdf might not originate from a model).

If you want to be able to give someone a model+dataset combination that they can launch easily, you could publish the model as a .vpm, together with the desired dataset. You could do that multiple times, which would waste a small amount of space due to redundant storage of the model, but it should work fine.

Just in case it helps clarify things:

A .mdl file contains only model structure (stock, flow, auxiliary, constant, lookup and data equations). It may include a stock-flow or causal loop diagram, though that's optional in DSS/Pro. You can produce tree diagrams etc. from the model structure, but not graphs or tables.

A .vdf file contains only numerical output (time series and constants) and variable names, but not the structure needed to generate diagrams. You can produce graphs, tables, etc. of the behavior in a .vdf, and use one .vdf as input to a model to produce another .vdf.

Normally when we refer to a "scenario" we mean a model plus any parameter changes needed to generate a particular run of the model. Those parameter changes might be stored in a .cin (constant changes) file, and the output from running the scenario would be a .vdf.

In DSS & Pro, you can open a .vdf as if it were a model, in which case you can see the list of variables but not the structure (equations) of the model that generated the .vdf. In PLE/Plus, and for normal use, you need the model to make sense of the .vdf.

So, normally, to view a scenario that you've already run, you need to (a) open the model (.mdl), to get the structure and (b) load the dataset (.vdf) containing the behavior, via the Dataset tab of the Control Panel. It should not be necessary to re-run the model.

[irene]

Got it!! Thank you very very much.
irene