Search found 1311 matches

by LAUJJL
Sun Feb 20, 2022 5:03 pm
Forum: Vensim
Topic: model about the staircase elevator problem exposed by Tom in the facebook forum
Replies: 2
Views: 533

another better model about the staircase problem

Hi A better version 6 that adds the calculation of the resting time in the elevator, especially if the starting time of the rest is close to the end of the climbing the elevator. It renames too most of the auxiliaries to initials, which is clearer. It calculates as initial the total time spent, show...
by LAUJJL
Sat Feb 19, 2022 6:39 pm
Forum: Vensim
Topic: another run about the problem exposed by Tom
Replies: 0
Views: 407

another run about the problem exposed by Tom

the run is joined
by LAUJJL
Sat Feb 19, 2022 6:34 pm
Forum: Vensim
Topic: model about the staircase elevator problem exposed by Tom in the facebook forum
Replies: 2
Views: 533

model about the staircase elevator problem exposed by Tom in the facebook forum

HI
Here is th model joined.
if somebody does not understand it, just ask.
I could not upload the published model?
i download the .mdl


JJ
by LAUJJL
Wed Feb 02, 2022 11:36 am
Forum: Vensim
Topic: two models explaining how to correct some errors found in the world3 model
Replies: 1
Views: 414

Re: two models explaining how to correct some errors found in the world3 model

A slight change in both models, to avoid an unit errors in the mortality 0 to 14 using the stricte unit error.
JJ
by LAUJJL
Sun Jan 30, 2022 7:13 pm
Forum: System Dynamics Discussion
Topic: Population Model
Replies: 6
Views: 1213

Re: Population Model

the population model is very approximative and does not resist to extreme conditions tests. For example, if the births are set to constant 0 with the synthesim starting at year 1900 and the final time set to 2200. 8 % of the initial population is still in life 200 years later. It comes from the fact...
by LAUJJL
Sun Jan 30, 2022 7:11 pm
Forum: System Dynamics Discussion
Topic: Population Model
Replies: 6
Views: 1213

Re: Population Model

HI
In Vensim, the deaths arrow is going outward and not inward and the loop is still balancing like in your CD.
by LAUJJL
Thu Jan 27, 2022 9:58 am
Forum: System Dynamics Discussion
Topic: Population Model
Replies: 6
Views: 1213

Re: Population Model

joined a simplistic population model. You can vary with the sysnthesim the average lifetime and the average fertility or the initial population and see what happens. JJ
by LAUJJL
Thu Jan 27, 2022 9:26 am
Forum: System Dynamics Discussion
Topic: Population Model
Replies: 6
Views: 1213

Re: Population Model

Hi The deaths loop is a balancing loop and the births one is a reinforcing loop. Balancing loops do not necessarily need a goal. If the population is increasing the births are increasing as the deaths do, but births are added and deaths are subtracted to the population and this makes the difference ...
by LAUJJL
Thu Jan 27, 2022 8:34 am
Forum: System Dynamics Discussion
Topic: Population Model
Replies: 6
Views: 1213

Re: Population Model

Hi
Can you post a vensim model that can be run, to illustrate your ideas with concrete runs. Regards. JJ
by LAUJJL
Mon Jan 24, 2022 6:18 pm
Forum: Vensim
Topic: two models explaining how to correct some errors found in the world3 model
Replies: 1
Views: 414

two models explaining how to correct some errors found in the world3 model

Hi

I have uploaded some corrections from the models included in a topic of the discuss forum of the system dynamics society web site started by Jack Jarich. I choosed to upload these two Vensim models here not being able to upload them in the discuss forum.
Best regards.
JJ
by LAUJJL
Mon Oct 11, 2021 9:09 pm
Forum: Vensim
Topic: Sub-model: working model and graphical presentation of sub-model connection?
Replies: 4
Views: 1604

Re: Sub-model: working model and graphical presentation of sub-model connection?

Yes, you have to make the connections by yourself between the main model and the submodels and it will then work. JJ
by LAUJJL
Thu Oct 07, 2021 1:55 pm
Forum: Vensim
Topic: sub-sub-submodekls
Replies: 2
Views: 1254

Re: sub-sub-submodekls

One of the main interests (at least for me) is to split a big model into smaller ones to make it easier to test them. Unfortunately, you can only test the sub-models mathematically, testing that there is no equation error. The problem comes from the necessity to find a value for some variables that ...
by LAUJJL
Thu Oct 07, 2021 12:06 pm
Forum: Vensim
Topic: sub-sub-submodekls
Replies: 2
Views: 1254

sub-sub-submodekls

Is it possible to have multiple levels of sub models?
by LAUJJL
Sat Oct 02, 2021 10:15 am
Forum: Vensim
Topic: an unchangeable constant when saved in a .cin file generates an error when running a model with the .cin file
Replies: 3
Views: 1433

Re: an unchangeable constant when saved in a .cin file generates an error when running a model with the .cin file

Hi When i set a constant as unchangeable it is just not to change it and not that it appears as changeable when setting the run. So i know that a unchangeable constant cannot be changed and I do not want to change it in any circumastances. in my model joined there is constant named const and set as ...
by LAUJJL
Sat Oct 02, 2021 9:31 am
Forum: Vensim
Topic: an unchangeable constant when saved in a .cin file generates an error when running a model with the .cin file
Replies: 3
Views: 1433

an unchangeable constant when saved in a .cin file generates an error when running a model with the .cin file

Hi the problem was already occuring with 9.0 DSS version. I downloaded the latest version and the problem is still there; I join a simplistic model with one unchangeable constant and its associated .cin file. whe one runs the model an error is reported. This happens with any model with unchangeable ...
by LAUJJL
Fri Aug 06, 2021 1:48 pm
Forum: Vensim
Topic: new user interface
Replies: 1
Views: 719

new user interface

Is it possible with the Vensim 9 version to keep the old user interface?
by LAUJJL
Mon Mar 22, 2021 3:48 pm
Forum: Vensim
Topic: erasing multiple runs
Replies: 1
Views: 819

erasing multiple runs

it is still not possible to erase multiple runs together and one must do it one by one with the latest DSS release. JJ
by LAUJJL
Mon Feb 08, 2021 3:29 pm
Forum: Vensim
Topic: resezing the lookup graph window
Replies: 1
Views: 850

resezing the lookup graph window

Hi

If i want to change with the mouse the grapj lookup table on the graph directly, it is not very easy to do, because the window is too small. Is it possible to increase the size of the graph lookup window, so that it occupies the whole screen for example. Regards. JJ
by LAUJJL
Sat Dec 19, 2020 4:00 pm
Forum: Vensim
Topic: Bugs in the latest Vensim DSS version
Replies: 2
Views: 1136

Re: Bugs in the latest Vensim DSS version

I have sent the model to vensim@vensim.com . JJ
by LAUJJL
Fri Dec 18, 2020 5:08 pm
Forum: Vensim
Topic: Bugs in the latest Vensim DSS version
Replies: 2
Views: 1136

Bugs in the latest Vensim DSS version

Hi The first bug is the more annoying. If one uses a string variable, and one wants to modify its value with the sim setup button, before launchig a simulation it erases all the constant values coming from an eventual .cin file. The only solution is to modify the equation of the string file, to avoi...
by LAUJJL
Sat Dec 05, 2020 9:40 am
Forum: Ventity
Topic: characters accepted in Ventity
Replies: 9
Views: 3988

Re: characters accepted in Ventity

Is it possible to have a documentation and price for the parallel vensim version? JJ
by LAUJJL
Fri Dec 04, 2020 7:55 pm
Forum: Ventity
Topic: characters accepted in Ventity
Replies: 9
Views: 3988

Re: characters accepted in Ventity

I did not know that there is a parallel vensim version that works on multiple cores. I have tested sensitivity analysis, and most of the time it had more drawbacks than advantages. but i can still try again. But i like solutions where you have control on what is calculated. I am anyhow very interest...
by LAUJJL
Fri Dec 04, 2020 6:53 pm
Forum: Ventity
Topic: characters accepted in Ventity
Replies: 9
Views: 3988

Re: characters accepted in Ventity

HI Tom I use parallel simulations for many reasons. My models having stochastic inputs, it is often necessary to run parallel simulations for optimization for instance. It could be possible to run a stochastic optimization, but i need to survey too not only average pay offs, but minimum too, and I c...
by LAUJJL
Fri Dec 04, 2020 11:28 am
Forum: Ventity
Topic: characters accepted in Ventity
Replies: 9
Views: 3988

Re: characters accepted in Ventity

Yes I join a package file. It complies and runs quickly in Vensim but if one changes the subscript sim from s1 to (s1-s100) if is extermely slow to compile while still running quite quickly and generates a huge file. As the model is not finished and needs additionnal subscripts, i will not been able...
by LAUJJL
Sun Nov 29, 2020 1:26 pm
Forum: Vensim
Topic: Need a little guidance
Replies: 5
Views: 1949

Re: Need a little guidance

download old 32 bits version