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Hello, I would like to add an influence of a factor on itself: for example Population increases by itself (growth rate). In the same order of ideas, in the insight matrix we can see the effect of a factor on itself. How can it be explained to a stakeholder? Thanks! Grégoire.

An impact onto itself only through another factor. e.g. a stock representing the current population and a flow factor increasing this stock.
In the qualitative analysis of the insight matrix you see from a factor's position on the vertical y-axis that it is either in a feedback loop or influencing via delays.
If reinforcing feedback loops are dominant it is either increasingly positive in its impact or increasingly negative, a vicious or virtuous cycle. If balancing feedback loops prevail the impact decreases, possibly even switching from positive to negative or vice versa.
You can show this behavior by switching between short, mid, and long term. Easy examples are interests on your bank account for R-loops and the depletion of resources and their price or B-loops.
Did I get your question right?

_________________
Kai Neumann

Consideo

Yes Kai, the loops allow a factor to impact on itself, but it seemed difficult to understand for our partners. I was thinking a bit more about that this morning, and the way I ended up putting it was: if we change externally a factor x, it will impact the same factor x: for example if there is a spill (not in the model) in a lake, the "pollution" factor will increase, and this would impact "pollution"...

For the first part of my question, I used beforeValue() to implement a self-reinforcing loop (arrow: from is same as to). But now way to do this in qualitative mode (you could eventually modify the code so iModeler allows assigning an influence from a factor to itself, and add a curved arrow on the factor for display...

EDIT: ok I understand: I add a factor called "growth rate" which is say 0.1*population, which feeds back into population. Still the curved arrow would be nice