data type

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bahri
Senior Member
Posts: 61
Joined: Wed May 11, 2016 4:43 am
Vensim version: DSS

data type

Post by bahri »

Hi,

I have searched what I need to know in this forum but no luck.
My question are:

1. How do I create variable with "data type" ?
2. Is that possible to use "accumulate function" to accumulate "a stock variable" ?
3. Is that "get data at time function" only works for "data type" ?
Administrator
Super Administrator
Posts: 4573
Joined: Wed Mar 05, 2003 3:10 am

Re: data type

Post by Administrator »

bahri wrote: Tue Jun 19, 2018 3:06 pm1. How do I create variable with "data type" ?
In the equation editor, there is a field titled "Type", select "Data" from here.
bahri wrote: Tue Jun 19, 2018 3:06 pm2. Is that possible to use "accumulate function" to accumulate "a stock variable" ?
To accumulate something, you use a stock.
bahri wrote: Tue Jun 19, 2018 3:06 pm3. Is that "get data at time function" only works for "data type" ?
Correct. What do you need to do?


The following might help.
http://www.vensim.com/documentation/ind ... ?usr16.htm
Advice to posters seeking help (it really helps us to help you)
http://www.ventanasystems.co.uk/forum/v ... f=2&t=4391

Units are important!
http://www.bbc.co.uk/news/magazine-27509559
tomfid
Administrator
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Joined: Wed May 24, 2006 4:54 am

Re: data type

Post by tomfid »

1. http://vensim.com/documentation/usr16.htm

2. You can use CUMULATE/CUMULATEF to calculate cumulative values of data, but it's not the same as a regular stock (INTEG). http://vensim.com/documentation/fn_cumulate.htm

3. Correct. http://vensim.com/documentation/fn_get_data_at_time.htm
bahri
Senior Member
Posts: 61
Joined: Wed May 11, 2016 4:43 am
Vensim version: DSS

Re: data type

Post by bahri »

Hi again,

What I meant is when I choose "constant" or "auxiliary" or "level",
I can type any value(s) or expressions.
But, for "data type", I did not any spaces to type values or mathematical expressions.

Could you please tell me how to create a variable with a "data type" ?

Next, I have a stock (A) and model's time is month.
I want to get a cumulative value of A for every year.
What shall I do ?
Administrator
Super Administrator
Posts: 4573
Joined: Wed Mar 05, 2003 3:10 am

Re: data type

Post by Administrator »

I'd start by doing a Vensim tutorial. On this page you will find a really good Vensim PLE tutorial.
http://www.public.asu.edu/~kirkwood/sysdyn/SDRes.htm

This will teach you what you need to get started.
Advice to posters seeking help (it really helps us to help you)
http://www.ventanasystems.co.uk/forum/v ... f=2&t=4391

Units are important!
http://www.bbc.co.uk/news/magazine-27509559
tomfid
Administrator
Posts: 3804
Joined: Wed May 24, 2006 4:54 am

Re: data type

Post by tomfid »

The user guide link above explains the data options, but the short answer is, set the Sub-Type of the data variable to "Equation" in the equation editor.

A stock is an accumulation, so I'm not quite sre what you're asking.
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