hi everyone
I have encountered some errors in simulating Vensim.the error says variable 'not used in the model'
I chose the 'supplementary' option but it was not cleared.
and another error is 'simultaneous equation involving : (variable)'
thanks.
Error Message
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Re: Error Message
It's impossible to help you unless you upload the model.
Setting a variable as 'supplementary' should clear the warning. It's not an error, it's telling you that you have a calculation that is not used.
Simultaneous equations means you've probably got an error in the logic of your model.
Setting a variable as 'supplementary' should clear the warning. It's not an error, it's telling you that you have a calculation that is not used.
Simultaneous equations means you've probably got an error in the logic of your model.
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
http://www.ventanasystems.co.uk/forum/v ... f=2&t=4391
Units are important!
http://www.bbc.co.uk/news/magazine-27509559
Re: Error Message
Hello again.
This is my model that errors on
This is my model that errors on
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Re: Error Message
The equation for "qpd0" is clearly incorrect. You cannot use "qpd0" to calculate "qpd0".
qpd0 = IF THEN ELSE(TPD=0, IF THEN ELSE(HD-qpd0>=qp-qpd0, qp-qpd0 , qp-qpd0*HD-qpd0/qp-qpd0 ) , 0 )
It's difficult to offer any advice here. I have no idea what "qpd" means and as there are no units in the model, it's impossible to guess.
qpd0 = IF THEN ELSE(TPD=0, IF THEN ELSE(HD-qpd0>=qp-qpd0, qp-qpd0 , qp-qpd0*HD-qpd0/qp-qpd0 ) , 0 )
It's difficult to offer any advice here. I have no idea what "qpd" means and as there are no units in the model, it's impossible to guess.
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
http://www.ventanasystems.co.uk/forum/v ... f=2&t=4391
Units are important!
http://www.bbc.co.uk/news/magazine-27509559
Re: Error Message
Actually I used the equation from this article for my college project.
That's weird for me too. I have no idea about it.
I asked my teacher and he said that might be a 'recursive function'.
Any ideas?
Thank you.
That's weird for me too. I have no idea about it.
I asked my teacher and he said that might be a 'recursive function'.
Any ideas?
Thank you.
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Re: Error Message
All I can suggest is start at section 4.3 of that document and implement each equation 1 at a time.
It's not something I would want to do. It looks awful.
PS. I've removed the paper as you need the author's permission to post on a public forum such as this.
It's not something I would want to do. It looks awful.
PS. I've removed the paper as you need the author's permission to post on a public forum such as this.
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
http://www.ventanasystems.co.uk/forum/v ... f=2&t=4391
Units are important!
http://www.bbc.co.uk/news/magazine-27509559
Re: Error Message
The subscript on QPD0 on the left side is vcd, and on the right side it's vc'd or vcd'. I'm not sure if the ' (prime) refers to differentiation or something else, but it's possible that the left and right side expressions are distinct things.
/*
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Advice to posters (it really helps us to help you)
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Blog: http://blog.metasd.com
Model library: http://models.metasd.com
Bookmarks: http://delicious.com/tomfid/SystemDynamics
*/