I am looking for a way to model plants biological life cycle. The time is not fixed for each stage and we have, at least 4 stages: seedlings (1 year old), young not productive (4 years old), productive young (6 years old), productive mature plants (10 years old), senile plants (30 years old or more).
This is necessary because fruits production vary in each stage, also mortality etc.
I've tried to implement it like a aging chain cohort using shift if true function, but, as I'm new to Vensim syntax, I have no success.
Anyone have any clues, tips or tricks that can help me with it (the aging chain cohort specifically).
Thanks in advance.
G
Plants Biological Life Cycle
Hi JJ,
I don't think I'm asking for someone build my models... This is not a forum for commercial relationships I guess...
I just couldn't find any similar models to look at... specially because the issues regarding published models quality (discussed already in somewhere...).
Also, I think that if you have nothing good to say, just say anything.
Thanks anyway.
Best whishes.
G.
[Edited on 30-10-2008 by geamaro]
I don't think I'm asking for someone build my models... This is not a forum for commercial relationships I guess...
I just couldn't find any similar models to look at... specially because the issues regarding published models quality (discussed already in somewhere...).
Also, I think that if you have nothing good to say, just say anything.
Thanks anyway.
Best whishes.
G.
[Edited on 30-10-2008 by geamaro]
Plants
Hi Gemao
To help you it is necessary to have a precise question.
You are asking a very general question about your problem.
What do you want to do? What is the problem?
Or maybe you just want to build a model that describes the
growth of the life cycle of the plants. This is called a systemic model.
you must decide what to put in the model, starting preferably with a minimum of factors and adding them lately.
You must too know if you have reference modes of your problem and the possibility to build a model from the past.
Is it a commercial model or an academic one?
Your problem is not very peculiar and there should be
examples in the academic litterature that look like.
For example there is a model of the forestry industry in New
Zealand in a book I have studied lately that deals with the growth of trees, price, etc...
There must be other cases in other books.
Where did you look to find some similar models? (books, reviews, conference papers etc..)
Regards.
JJ
[Edited on 30-10-2008 by LAUJJL]
To help you it is necessary to have a precise question.
You are asking a very general question about your problem.
What do you want to do? What is the problem?
Or maybe you just want to build a model that describes the
growth of the life cycle of the plants. This is called a systemic model.
you must decide what to put in the model, starting preferably with a minimum of factors and adding them lately.
You must too know if you have reference modes of your problem and the possibility to build a model from the past.
Is it a commercial model or an academic one?
Your problem is not very peculiar and there should be
examples in the academic litterature that look like.
For example there is a model of the forestry industry in New
Zealand in a book I have studied lately that deals with the growth of trees, price, etc...
There must be other cases in other books.
Where did you look to find some similar models? (books, reviews, conference papers etc..)
Regards.
JJ
[Edited on 30-10-2008 by LAUJJL]
Hi geamaro,
I think you could have one compartment for each age class. You could use de DELAY N function for the rates between the compartments. Take a look in the simple model Gafanhotos.mdl at www.sgrillo.net It has only two age classes (for an insect population) but could be used as example.
[Edited on 3-12-2008 by sgrillo]
I think you could have one compartment for each age class. You could use de DELAY N function for the rates between the compartments. Take a look in the simple model Gafanhotos.mdl at www.sgrillo.net It has only two age classes (for an insect population) but could be used as example.
[Edited on 3-12-2008 by sgrillo]
R. Sgrillo
www.sgrillo.net
www.sgrillo.net