BUG: in RETURN-KIDS, nlogo.nvm.RuntimePrimitiveException: That person is dead.

[mariopaolucci]

Here, pretty self-explanatory. The bug comes out in the runs of the 0.9.3 series

Run #3, RUNTIME ERROR: That person is dead.
error while observer running OF
  called by (anonymous command: [ a -> let last but-last a if any? turtle-set father [ if [ age ] of last a >= 18 [ if random-float 1 < 6 / first a [ ask last a [ create-offspring-link-from father ] set removed-fatherships remove a removed-fatherships ] ] ] ])
  called by procedure RETURN-KIDS
  called by procedure GO
  called by procedure __EVALUATOR
org.nlogo.nvm.RuntimePrimitiveException: That person is dead.
        at org.nlogo.nvm.AnonymousCommand.perform(AnonymousProcedure.scala:181)
        at org.nlogo.nvm.AnonymousCommand.perform(AnonymousProcedure.scala:158)
        at org.nlogo.prim.etc._foreach.perform(_foreach.scala:33)
        at org.nlogo.nvm.Context.stepConcurrent(Context.java:107)
        at org.nlogo.nvm.ConcurrentJob.step(ConcurrentJob.scala:65)
        at org.nlogo.job.JobThread.runPrimaryJobs(JobThread.scala:133)
        at org.nlogo.job.JobThread.$anonfun$run$1(JobThread.scala:68)
        at scala.runtime.java8.JFunction0$mcV$sp.apply(JFunction0$mcV$sp.java:23)
        at scala.util.control.Exception$Catch.apply(Exception.scala:228)
        at org.nlogo.api.Exceptions$.handling(Exceptions.scala:41)
        at org.nlogo.job.JobThread.run(JobThread.scala:66)

[mariopaolucci]

To reproduce the issue, I have set

set num-persons 1000
set num-oc-persons 1000
set number-crimes-yearly-per10k 10000

and I have changed a line of code to pump up arrests: set arrest-rate number-arrests-per-year / ticks-per-year / number-crimes-yearly-per10k / 1000 * count persons instead of set arrest-rate number-arrests-per-year / ticks-per-year / number-crimes-yearly-per10k / 10000 * count persons.

I run with while [length removed-fatherships < 3] [go] print "finito" and I kill all the prisoners with observer> ask turtle-set map [a -> last but-last a] removed-fatherships [ if my-job != nobody [ ask my-job [ set my-worker nobody ] ] if my-school != nobody [ ask my-school [ set my-students other my-students ] ] die] (bit long, ok).

Under those conditions, I get removed-fatherships to length 8 at step 14. This means that even if the kids are very small, I'll get a re-add before long - that is, if the kids are 12, they will get to 18 in 72 steps.. how old are they? And then there's just a chance they get re-added- should have tweaked that too.

Indeed, it uncooly arrived to 230 steps without anything happening. I'm starting to think it's the turtle-set that solved it for dead fathers - maybe it's a dead offspring?

And yes, it was a dead OFFSPRING - exactly same error obtained - something that points to family reunitions happening too rarely. Let's review that:

       if (random-float 1) < 6 / (first a) [
         ask last a [ create-offspring-link-from father ]
         set removed-fatherships remove a removed-fatherships
       ]

Can't find a way to explain that - 6 / the number of ticks? That variable contains ((18 * ticks-per-year + birth-tick) - ticks). Well it's ok, it amounts to just the number of ticks spent in separation, and makes them slower to return. However, in two years they should all be back.

[mariopaolucci]

Ok, it should be solved when interface goes up.. in the end I clean up the list during the death routine.