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Author Topic: EVAC : Random Seed  (Read 3546 times)

Michele

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EVAC : Random Seed
« on: February 02, 2010, 08:53:40 am »

Hi,
in the Evac properties there is a flag possibility on "Use Random Seed".
When flagged, the FDS command "NOT_RANDOM=.TRUE." is added to the code line. The initial position and characteristics of the agents will therefore NOT chosen randomly (I suppose will be the same as the previous simulation).
This means that flagging the "Use Random Seed" results in NON-random agents selection (which is in contrast with the flag name...).

Is this interpretation correct?

Thanks
Michele
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Charlie Thornton

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Re: EVAC : Random Seed
« Reply #1 on: February 02, 2010, 09:27:28 am »

Yes.  It's backwards.  That's a bug.

Thanks for reporting the bug, I've added it to our tracking system.
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Michele

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Re: EVAC : Random Seed
« Reply #2 on: February 03, 2010, 07:40:30 am »

Same with "Calculate Evac Flow Field".
When flagged it return the FDS command "EVACUATION_MC_MODE=.TRUE." which means that the evacuation flow field is NOT (re)calculated. Existing CHID_evac.eff file is to be read (or eventually EFF recalculated if file is not existing).
Am I right?
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Charlie Thornton

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Re: EVAC : Random Seed
« Reply #3 on: February 03, 2010, 09:19:28 am »

Agreed.  That also is a bug.  I've added it to our tracker.

Should read, "Load Flow Field from EFF File"

Though, I'm not even sure why Timo put that in there.  Flow field calculations are really fast compared to almost anything else you might do in the evac simulator.  I suppose it might be handy for debugging.
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Michele

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Re: EVAC : Random Seed
« Reply #4 on: February 03, 2010, 10:26:28 am »

Yes, I guess the reason for that command is for debugging and eventually for simulation set-up.
Even in the user's guide it's written "[...] one is saving some CPU seconds [...]".
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