Search found 148 matches

by RWTH_FCN
Wed Oct 28, 2020 4:18 pm
Forum: Vensim
Topic: Somebody help me please!! ramp and pulse train combination
Replies: 33
Views: 14487

Re: Somebody help me please!! ramp and pulse train combination

Administrator wrote: Wed Oct 28, 2020 4:02 pm Is pulse func in your savelist?
No, but I removed the savelist completly and it works now!
by RWTH_FCN
Wed Oct 28, 2020 3:57 pm
Forum: Vensim
Topic: Somebody help me please!! ramp and pulse train combination
Replies: 33
Views: 14487

Re: Somebody help me please!! ramp and pulse train combination

tomfid wrote: Wed Oct 28, 2020 3:35 pm Seems fine to me. Pulse starts at 3 and lasts for 5?
I do not see any pulse when I open a graph for pulse func.
by RWTH_FCN
Wed Oct 28, 2020 3:51 pm
Forum: Vensim
Topic: Somebody help me please!! ramp and pulse train combination
Replies: 33
Views: 14487

Re: Somebody help me please!! ramp and pulse train combination

Administrator wrote: Wed Oct 28, 2020 2:36 pm Can you let us know which parameter is the problem one, and why you think it is not working properly?
Pulse func. Because it does not produce a pulse at time 3.
by RWTH_FCN
Wed Oct 28, 2020 11:35 am
Forum: Vensim
Topic: Somebody help me please!! ramp and pulse train combination
Replies: 33
Views: 14487

Re: Somebody help me please!! ramp and pulse train combination

Here's a simple structure that generates pulses. There are a couple limitations - width=TIME STEP, and it wouldn't work with RK4 integration. I'm guessing it would work for your case though. PULSE TRAIN alternative 1.mdl In the attached model the pulse function does not work properly. I was wonderi...
by RWTH_FCN
Mon Oct 12, 2020 4:24 pm
Forum: Ventity
Topic: Market action
Replies: 17
Views: 11350

Re: Market action

Yes - that should work. It'll just be processing a collection of 1 entity on one side of the market. I'll see if I can come up with an example. That would be great. The examples in this link might be useful for designing a one to many allocation: https://www.ventanasystems.co.uk/forum/viewtopic.php...
by RWTH_FCN
Sat Oct 10, 2020 11:16 pm
Forum: Ventity
Topic: Market action
Replies: 17
Views: 11350

Re: Market action

tomfid wrote: Fri Oct 09, 2020 4:05 pm Actually, the two-sided Market action does populate the clearing price. So, I think a workaround for now would be to use the two sided version, even if the supply or demand side only has one entity.
What about one sided action? Does it support Market with one demander and several suppliers?
by RWTH_FCN
Fri Oct 09, 2020 9:56 am
Forum: Ventity
Topic: connection with other softwares
Replies: 3
Views: 3981

Re: connection with other softwares

Most of the packages in other software support simple formulas of SD. Is there any software or a package in Python which supports formulas of the allocation section (Allocation functions)?
by RWTH_FCN
Tue Oct 06, 2020 10:01 pm
Forum: Ventity
Topic: Market action
Replies: 17
Views: 11350

Re: Market action

tomfid wrote: Tue Oct 06, 2020 8:14 pm Actually, you're right - it's still returning 0. I'll bump up the priority and see what ETA looks like.
In help section, it's mentioned that it is currently inoperative as well. Is there any hope for having it this year?
by RWTH_FCN
Mon Oct 05, 2020 8:43 am
Forum: Ventity
Topic: Market action
Replies: 17
Views: 11350

Re: Market action

tomfid wrote: Tue Sep 29, 2020 8:54 pm In Ventity, these are implemented as actions. They're in the Actions section under Defining Entity Types in the Help.
Do you have any estimate when Market Price will be activated in the Action section?
by RWTH_FCN
Tue Sep 29, 2020 8:20 pm
Forum: Ventity
Topic: Market action
Replies: 17
Views: 11350

Re: Market action

Hi,
I was wondering how can I use different allocation functions such as DEMAND/SUPPLY AT PRICE or FIND MARKET PRICE in Ventity?
by RWTH_FCN
Thu Sep 24, 2020 10:24 am
Forum: Vensim
Topic: Integrating time step of optimization problem
Replies: 32
Views: 14877

Re: Integrating time step of optimization problem

I would like to combine SD with agent based modeling to model this sort of auctions. I am going to use current SD model and I was wondering can I combine this platform with ABM in Ventity?
by RWTH_FCN
Fri Mar 06, 2020 10:41 am
Forum: Vensim
Topic: Question about deleting previous runs
Replies: 4
Views: 2505

Re: Question about deleting previous runs

Administrator wrote: Fri Mar 06, 2020 10:37 am If you close Vensim, you will be able to delete them manually.
Ah, you are right. thanks
by RWTH_FCN
Fri Mar 06, 2020 10:26 am
Forum: Vensim
Topic: Question about deleting previous runs
Replies: 4
Views: 2505

Re: Question about deleting previous runs

What version of Vensim are you using? You can always delete them manually as well by browsing to the folder where they are stored. Version 6.4. Actually, when I want to delete them manually I get an error that they cannot be deleted becasue file is open in Vensim. So, I decided to remove them in Ve...
by RWTH_FCN
Fri Mar 06, 2020 10:03 am
Forum: Vensim
Topic: Question about deleting previous runs
Replies: 4
Views: 2505

Question about deleting previous runs

Hi,

I have run model several times and since dataset are huge I want to delete them. To do so, I should go in Windows->Control panel->Datasets. The problem is that I can not delet them and they stay here. Do you have any ideas why it heppens?
by RWTH_FCN
Tue Feb 04, 2020 1:27 pm
Forum: Vensim
Topic: User-defined file setup in Sensitivity Simulation - for multiple parameters
Replies: 14
Views: 5694

Re: User-defined file setup in Sensitivity Simulation - for multiple parameters

I would just include the things that vary - the rest could be left in a default cin file. Then you include the sample in a sensitivity simulation via a vsc using the File method. Sounds plausible. If model takes 2 hours for run, is it possible to do stochastic optimization as well or do you just su...
by RWTH_FCN
Tue Feb 04, 2020 12:37 pm
Forum: Vensim
Topic: User-defined file setup in Sensitivity Simulation - for multiple parameters
Replies: 14
Views: 5694

Re: User-defined file setup in Sensitivity Simulation - for multiple parameters

In your case, you'd have to transpose your cin file(s) into a sensitivity sample file. This isn't as hard as it sounds. If you import a cin file into Excel, and use text to columns to break things at the =, you get a column of variable names and a column of values. Do this once per file, then merge...
by RWTH_FCN
Tue Feb 04, 2020 8:42 am
Forum: Vensim
Topic: User-defined file setup in Sensitivity Simulation - for multiple parameters
Replies: 14
Views: 5694

Re: User-defined file setup in Sensitivity Simulation - for multiple parameters

In Stochastic Optimization page of Manual, I encountered this sentence: "The stochastic optimization option facilitates optimization over an array of random or user-specified scenarios without first arraying the model. The total payoff is the sum of the payoffs of the individual runs in the sen...
by RWTH_FCN
Mon Feb 03, 2020 3:46 pm
Forum: Vensim
Topic: User-defined file setup in Sensitivity Simulation - for multiple parameters
Replies: 14
Views: 5694

Re: User-defined file setup in Sensitivity Simulation - for multiple parameters

When you say scenarios, do you mean that you have 4 files, each with a different set of variables, and you want to merge them, or ... ? Yes, I have four input files ( four CIN files). Each of them includes many variables like fuel prices, installed capacities, co2 prices, transmission constraints, ...
by RWTH_FCN
Mon Feb 03, 2020 10:53 am
Forum: Vensim
Topic: User-defined file setup in Sensitivity Simulation - for multiple parameters
Replies: 14
Views: 5694

Re: User-defined file setup in Sensitivity Simulation - for multiple parameters

I see. In that case, it does seem sensible to do some kind of combinatorial resampling from the individual columns. Unfortunately, the Vensim file sensitivity isn't set up to do this, but I'll take a look - it might be simple to implement. I was also wondering how can we feed 4 scnearios simultaneo...
by RWTH_FCN
Mon Jan 27, 2020 4:05 pm
Forum: Vensim
Topic: Hearne' method
Replies: 6
Views: 4057

Re: Hearne' method

It seems impractical in a large model - just too many parameters to explore. Although he has not addressed what large model means from Author's point of view, he has mentioned in the paper that "The application of this simpler method before resorting to the triangular functions might yield com...
by RWTH_FCN
Mon Jan 27, 2020 3:55 pm
Forum: Vensim
Topic: Maximum value
Replies: 26
Views: 13140

Re: Maximum value

I think there may be a missing piece year - should min price be subscripted by year? If not, min yearly price[EndUse Region]=SUM(min price[EndUse Region]*is year[year!]) = ]=min price[EndUse Region]*SUM(is year[year!]) I have year as a subscript in the model. Anyway, I found a better solution for f...
by RWTH_FCN
Sun Jan 26, 2020 7:04 pm
Forum: Vensim
Topic: Maximum value
Replies: 26
Views: 13140

Re: Maximum value

The initial value of the input would have to be 0. It's possible that there's a 0 in the initialization step, even if the dynamic value is nonzero. Hard to say more without seeing equations and data. I cannot upload the model, but I hope these equations help to understand the problem. I want to cal...
by RWTH_FCN
Sun Jan 26, 2020 4:25 pm
Forum: Vensim
Topic: Maximum value
Replies: 26
Views: 13140

Re: Maximum value

tomfid wrote: Sun Jan 26, 2020 4:08 pm The initial value of the input would have to be 0. It's possible that there's a 0 in the initialization step, even if the dynamic value is nonzero. Hard to say more without seeing equations and data.
Sounds plausible. There is one 0 in initialization step. Any idea to solve it?
by RWTH_FCN
Sun Jan 26, 2020 3:35 pm
Forum: Vensim
Topic: Maximum value
Replies: 26
Views: 13140

Re: Maximum value

Administrator wrote: Sat Jan 25, 2020 8:04 pm Correct, that should get the minimum.
Do you have any suggestion why it always generates zero?
by RWTH_FCN
Sat Jan 25, 2020 7:18 pm
Forum: Vensim
Topic: Maximum value
Replies: 26
Views: 13140

Re: Maximum value

Administrator wrote: Mon Jul 10, 2017 12:48 pm This should work.

Code: Select all

MAX VALUE = SAMPLE IF TRUE ( A > MAX VALUE , A , A )
It works well for maximum. Is it correct for getting minimum?

Code: Select all

MIN VALUE = SAMPLE IF TRUE ( A <MIN VALUE , A , A )