subscript and subrange-population

lynchyml · Post by **lynchyml** » Tue Sep 08, 2009 6:16 am

I have rebuild a population model according to millenniuminstitute's T21 model.

there are several problems with subscript and subrange:

subscript range-age group-appears on the right,but not left

incorrect number of subscripts for age specific fertility distribution

incorrect number of subscripts for births

in correct number of subscripts for cohort

thank you very much!

LAUJJL · Post by **LAUJJL** » Tue Sep 08, 2009 8:31 am

It would be good first to put units in your model.
Try to build them independantly of the equatiions from the nature of the variable and then rebuild the equations with the help of this preliminary work. You may well correct the other errors you mention.
Regards.
JJ

lynchyml · Post by **lynchyml** » Wed Sep 09, 2009 1:09 am

thanks a lot for your suggestion,but I think the subrange of the model is the main problem.

LAUJJL · Post by **LAUJJL** » Wed Sep 09, 2009 8:57 am

Hi

Logically one does not understand the use of the subscript agegroup. You should try to replace this subscript by subranges of the first subscript age. There are already subranges from the subscript age, it is then difficult to see the utility to add a second subscript that duplicate these subranges.
But whatever your changes in the model, unit dimension is an absolute elementary necessity that is respected in all serious models whether small, medium, large or very large.
Regards.
JJ

[Edited on 9-9-2009 by LAUJJL]

LAUJJL · Post by **LAUJJL** » Wed Sep 09, 2009 9:31 am

Looking quickly at your model, I do not see how people are growing older. they seem not to grow older at all.
You should study both models; age.mdl and agechain.mdl and particularly the age.mdl that uses subscript mapping to simplify the sketch. They are available in the directory Vensim\models\sample\extra.
Subscript mapping is too explained in the user and reference guide.
Regards.
JJ

LAUJJL · Post by **LAUJJL** » Wed Sep 09, 2009 11:22 am

Joined a simple example that uses subscript mapping and considers cohorts of one year with population initialized at 100000 people of one year old, but can be changed at will.
It has no gender subscript but could be a good start for further developments.
JJ

Vishah · Post by **Vishah** » Sat Sep 19, 2009 8:42 am

Its was good to find this discussion. I was also developing a population model from scratch according to the T21 and faced the same problem with the subscripts and subrange.

Vishah · Post by **Vishah** » Sat Sep 19, 2009 9:24 am

I have looked through the age.mdl model and i kind of got it, but when i run the model, i still get the errors that need to be corrected. Can anyone help me on how do i deal with these errors? See the attachment for details

LAUJJL · Post by **LAUJJL** » Sat Sep 19, 2009 9:53 am

Hi Vishah

I can run the age.mdl with no problems and with no errors at least with no modifications.
The model I joined works too with no problems.
Are you using at least the Vensim Pro or DSS version?
the other versions have no subscripts, and the error may come from the Version.
Regards.
JJ

Vishah · Post by **Vishah** » Sat Sep 19, 2009 1:45 pm

Thank you for your response. I am actually looking through the model that you joined and its really of help.

Vishah · Post by **Vishah** » Sat Sep 19, 2009 1:54 pm

I want to create a new subrange "school going age". I know how to create the new subscript for this from the Users Guide, but they do not show how to select the ages in this range. E.G. when i am on "full" on the subscript control, when i click on the "school going age', it does not highlight the age i am interested in. It is not shown in the users guide on how to do this. Can anyone help. Tx in advance

LAUJJL · Post by **LAUJJL** » Sat Sep 19, 2009 2:38 pm

Hi Vishas

If you are on the full subscript and the subrange 'school going age appears' and you click on it, the ages should highlight underneath. If it does not, try cliking on the button at the right of the edit. It should go to the equation editor where you can modify the definition of the subrange.
A subrange is nothing more than a list separated by commas, of basic elements of the subscript.
Regards.
jj

Vishah · Post by **Vishah** » Sat Sep 19, 2009 2:44 pm

Thank you for your quick response, You have guided me on how to do it.