Re: [Swarm-Modelling] status_access_violation question

[Steve Railsback]

address@hidden wrote:
> Hello,
>
> I am currently in the midst of coding my first involved swarm model,
> which I am going to use in my dissertation research on early hominid
> food sharing.  I've just run across a problem that I'm unable to solve
> with my limited experience.  After I compile the executable (share.exe)
> and run it at the command prompt, the simulation runs successfully for
> anywhere from 50 to 700 time steps.  However, though it runs as it
> should, the model always bails with the following error message at some
> (seemingly random) point:
>
> 0 [main] share 1000 handle_exceptions: Exception:
> STATUS_ACCESS_VIOLATION

Yeah, these kind of errors are not so clear to find. In general, it 
means you are trying to use memory that isn't allocated--trying to store 
something in an array at a location bigger than the array size, trying 
to access a location in a Grid2D object that's beyond its boundaries, 
etc. When it happens after a model has run for a while, perhaps one of 
your agents is wandering off the edge of the world, etc.

You could try putting print statements wherever you use an array or 
space object, to print out the location you're trying to access before 
you actually do access it. Check carefully for logic errors that could 
cause the code to try to read a variable or array location that doesn't 
exist.

Steve R.

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