Search found 1455 matches

by LAUJJL
Mon Nov 11, 2024 9:04 am
Forum: Vensim
Topic: Reiterating Data
Replies: 17
Views: 337

Re: Reiterating Data

Hi

Here is the complete challenge with an excel file having the values of the challenge and the modified model that reads the value from the excel file. What else do you need as this works well? You can replace the sum that I use by a vector lookup as Tom proposes.

JJ
by LAUJJL
Mon Nov 11, 2024 8:11 am
Forum: Vensim
Topic: Simultaneous workaround
Replies: 5
Views: 66

Re: Simultaneous workaround

Simultaneous and find zero work like a black box because you don't see the intermediate results that lead to eventual convergence or not. I often prefer to use a vector in which I store the intermediate results that I calculate myself so that they converge. In short, I make my own simultaneous or fi...
by LAUJJL
Thu Nov 07, 2024 3:10 pm
Forum: Vensim
Topic: units for %
Replies: 10
Views: 192

Re: units for %

the epidemic.vdfx file
by LAUJJL
Thu Nov 07, 2024 3:05 pm
Forum: Vensim
Topic: units for %
Replies: 10
Views: 192

Re: units for %

Hi Not many Vensim users are familiar with this strict testing feature. For example, if you add 5 to a variable and that variable has a dimension, e.g. people/year, Vensim assumes that 5 has a dimension equal to that of the variable, unless the strict test is on, in which case there is a unit error ...
by LAUJJL
Thu Nov 07, 2024 7:53 am
Forum: Vensim
Topic: Reiterating Data
Replies: 17
Views: 337

Re: Reiterating Data

Hi Joined the model with the 10 values. i do not use 'sub" as a value for the index as it probably looks weird for you. Subscripts in Vensim are a bit difficult to understand especially the mapping system; But once you have understood it you will be able to model any logic without the use of an...
by LAUJJL
Wed Nov 06, 2024 7:43 pm
Forum: Vensim
Topic: units for %
Replies: 10
Views: 192

Re: units for %

If you click on model settings and units, on the top of the window you can check use stict testing. i just wanted to know if you use strict testing or not.

JJ
by LAUJJL
Wed Nov 06, 2024 5:00 pm
Forum: Vensim
Topic: Reiterating Data
Replies: 17
Views: 337

Re: Reiterating Data

Hi Here is the model. i have given artitrary valeus to the array that has to be dosnladed from the excel file, something that is easy to do. i do not know if it is quicker but the utility is that the process is clearer. One downlaods first the data in an array and then one makes at each time the val...
by LAUJJL
Wed Nov 06, 2024 11:24 am
Forum: Vensim
Topic: units for %
Replies: 10
Views: 192

Re: units for %

In this thread, there is a question of units. Are these strict or non-strict unit tests?

JJ
by LAUJJL
Wed Nov 06, 2024 11:13 am
Forum: System Dynamics Discussion
Topic: modelling GDP
Replies: 1
Views: 87

Re: modelling GDP

Just one remark: your GDP is not exogenous being modeled, but endogenous. For the rest, your model assumes an increase in GDP proportional to the GDP itself, which automatically generates exponential growth.

JJ
by LAUJJL
Mon Nov 04, 2024 9:21 am
Forum: Vensim
Topic: Reiterating Data
Replies: 17
Views: 337

Re: Reiterating Data

I would try downkoading the 8760 data in an array first and then use the modulo to make each time point equal to the corresponding element in the array

JJ
by LAUJJL
Sun Oct 27, 2024 8:38 pm
Forum: Vensim
Topic: SDEverywhere vs. reality checks
Replies: 5
Views: 497

Re: SDEverywhere vs. reality checks

Hi I have been using 'reality checks' for years. They have two disadvantages; they are interpreted then slow and at the time, they could not be run in batch mode for example by launching multiple runs from Excel using DLLs. It may be possible that we can now run reality checks in batch mode with new...
by LAUJJL
Sat Sep 28, 2024 11:08 am
Forum: Ventity
Topic: Modelica Simulation - Emmanuel Katto
Replies: 2
Views: 1021

Re: Modelica Simulation - Emmanuel Katto

Hi

Guido Wolf Reichert is a modelica specialist using system dunamics too, member of the SDS some years ago. But there is now some time that I had no news from him. You can either browse google with his name or use: gwr@bsl-support.de if it still works.

Best

JJ
by LAUJJL
Tue Sep 10, 2024 5:54 pm
Forum: Vensim
Topic: cannot change the font of the equation editor
Replies: 8
Views: 1986

Re: cannot change the font of the equation editor

If i set the options fonts to 8, in the equation editor, the numbers are very small. with 9, it becomes much better. with 10, there is a very small increase in size and with 11, the size in the editor is slightly better and the bigger I can get. But with 12, the size in the editor is again very smal...
by LAUJJL
Tue Sep 10, 2024 11:21 am
Forum: Vensim
Topic: cannot change the font of the equation editor
Replies: 8
Views: 1986

Re: cannot change the font of the equation editor

i have copied the numbers on word and verified the size. it is 8. But if i change the size to Arial 12, in the equation editor, there is no change
by LAUJJL
Tue Sep 10, 2024 8:23 am
Forum: Vensim
Topic: cannot change the font of the equation editor
Replies: 8
Views: 1986

Re: cannot change the font of the equation editor

I have selected different size points. For the moment 8 the smallest possible.
by LAUJJL
Mon Sep 09, 2024 1:53 pm
Forum: Vensim
Topic: cannot change the font of the equation editor
Replies: 8
Views: 1986

Re: cannot change the font of the equation editor

I have made the font Arial normal different size using tools>options>fonts>equation editor avery time savied and exited Vensim. It has not changed anything.
by LAUJJL
Sun Sep 08, 2024 1:27 pm
Forum: Vensim
Topic: cannot change the font of the equation editor
Replies: 8
Views: 1986

cannot change the font of the equation editor

Hi

The size of the fonts in the equation editor are very small and I do not know how to change them. i tried options and fonts and equation editor, and the size is ok but the editor stays the same.

JJ
by LAUJJL
Mon Jul 29, 2024 5:30 pm
Forum: Vensim
Topic: custom tables do not save time running down
Replies: 1
Views: 2760

custom tables do not save time running down

HI

If one click the time run down button and one saves a custom graph if one edits it again the run down button is no more clicked. this makes mipossible to use a custom graph with time running down. It works with any model and any custom graph. with the new gui.

Regards.

JJ
by LAUJJL
Sat Jul 13, 2024 9:27 am
Forum: Vensim
Topic: ack of simulation results
Replies: 5
Views: 4674

Re: ack of simulation results

There is a bug in your model. To find it you must understand why Cena stays equal to Cena rynkowa all the time. Start at time 0, and verify all the variables and their equations starting from Cena using the uses tree that have an influence on Cena rynkowa. if you do that with care, you will find the...
by LAUJJL
Wed Jun 19, 2024 3:53 pm
Forum: Vensim
Topic: Population Example with Conveyors
Replies: 4
Views: 4256

Re: Population Example with Conveyors

The two errors in the maturations happen just before the levels reach zéro. Some formulation errors generate strange behaviour in limit conditions. There is probably an error somewhere in the model. There is too an error in the population view of the world 3 model where the error disappears if one s...
by LAUJJL
Wed Jun 19, 2024 11:37 am
Forum: Vensim
Topic: Population Example with Conveyors
Replies: 4
Views: 4256

Re: Population Example with Conveyors

The use of a minimum in the 'young deaths' looks strange. Logically the maturation should calculate how many young people still alive are getting older; And this calculation should not be able to force the level to be negative. One must decide if the young people becoming young adults are still belo...
by LAUJJL
Thu Jun 13, 2024 4:45 pm
Forum: Vensim
Topic: control button not working the same way in DSS and reader
Replies: 2
Views: 3523

Re: control button not working the same way in DSS and reader

The model seems to work the same way than the DSS. Going to the view view 2 seems to be a bug.

it would be useful to have somewhere an explanation of the 9 added controls plus some exemples like the Venapps examples.

Regards.

JJ
by LAUJJL
Wed Jun 12, 2024 4:41 pm
Forum: Vensim
Topic: control button not working the same way in DSS and reader
Replies: 2
Views: 3523

control button not working the same way in DSS and reader

Hi The new DSS version has now all the controls available. I join two models that have both a button control. The first model essai.mdl has a button whose name is ‘go to next view’ and with a control that effectively goes to the next view. If one publishes the model into a .vpmx model and one opens ...
by LAUJJL
Tue May 14, 2024 9:32 am
Forum: Vensim
Topic: System Dynamics definition
Replies: 10
Views: 4222

Re: System Dynamics definition

The less math and more life experience.
by LAUJJL
Tue May 14, 2024 8:15 am
Forum: Vensim
Topic: System Dynamics definition
Replies: 10
Views: 4222

Re: System Dynamics definition

Hi

I think that advanced knowledge like control theory is more harmful than helpful because it may lead to think that the more math the better. I think that the less math the better.

JJ