Support for has_cycle() on sparse models #103
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tquatmann
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Oct 19, 2022
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| return storm::utility::graph::hasCycle(matrix, subStates); |
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This is problematic for MDPs, when we have one self-loop row first and then one non-selfloop row which induces a cycle with other states, right?
I think the "hasCycle" would need to have a "subChoices" input to make this work?
Alternatively, this method could also build an SCC decomposition and we then check if each SCC has size 1.
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You are right, this is indeed problematic.
I am open for other suggestion. The SCC decomposition might be a good idea.
I actually just wanted to have a simple function to check for acyclity. Unfortunately, hasCycle is not exactly giving me what I want. Maybe it makes sense to implement a better function in Storm directly.
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Checking whether a model is acyclic should be quite helpful.
Note that the current implementation first needs to find and exclude all states with self-loops, because the underlying Storm function is considering self-loops as cycles.
Thanks to @jipspel for some help.