On Friday, February 6, 2015 at 11:34:30 AM UTC-6, Jason Bertsche wrote: > > We've definitely discussed the idea of bag/multiset support in NetLogo > before, but, as was already noted in this thread, it would be a substantial > thing to introduce. In this particular situation, it seems like the use > case for multisets is not terribly difficult to work around, but I'd be > interested to hear about other cases in which people might find multisets > useful. If there's enough need for it, multiset support could *possibly* > be added, but my intuition is that the need didn't seem to arise in the > first 15 years of NetLogo's history, so what would cause it to arise now? >
Maybe it's significant that it wasn't until two years ago that there was enough motivation for someone (Nicolas) to introduce the *rnd* extension with more flexible agent selection options. To me those functions seem very valuable, but the NetLogo community got by without them for a long time. (I didn't need one until yesterday!) Then again, maybe there's been a qualitative change, in recent years, in the NetLogo community and the uses to which NetLogo is being put. (An emergent phenomenon!) So maybe the past isn't a reliable indicator of future needs. > I suspect it might also be opposed on grounds of complicating the > language. > I can easily understand that it would complicate the source code, and that that might be enough to make it not worth adding "agentbags". Does it complicate the NetLogo language, though, if agentset primitives knew how to deal with "agentbags". Maybe there's something I'm not seeing. > Either way, I think it's an interesting idea worth discussing. > > On 02/06/2015 11:18 AM, Bryan Head wrote: > > Glad you think that will work for you. I should note that if you want to > reproduce the random ordering behavior of `ask` and `with`, just put > `shuffle` before `agent-list`. For instance `foreach shuffle agent-list [ > ... ]` and `map [...] shuffle agent-list`. You'll take a performance hit, > but then they will behave more like the agentset primitives, and you won't > see artifacts cropping up from using the same order every time. > > On Fri Feb 06 2015 at 11:11:13 AM Marshall <[email protected] > <javascript:>> wrote: > >> Thanks Bryan--That's a good solution. Hadn't thought of it. (Seems >> obvious, now!) I'll probably do that. And I appreciate knowing that >> uniqueness is deeply embedded in the nature of agentsets. >> >> Roman, you're right--I should have called that what I was proposing an >> "agentmultiset". >> >> >> On Friday, February 6, 2015 at 10:30:05 AM UTC-6, Bryan Head wrote: >> >>> Hi Marshall, >>> >>> Writing you're own ask-procedure that operates on lists could be a >>> pretty easy workaround. For instance: >>> >>> to ask-list [ agent-list commands ] >>> foreach agent-list [ ask ? [ run commands ] ] >>> end >>> >>> which you then call like: >>> >>> ask-list agents-with-repeats task [ do-stuff ] >>> >>> Where `agents-with-repeats` is your list of agents. Note the `task` >>> primitive is unfortunately required. Besides that, this should pretty much >>> be a drop-in replacement for `ask` after you switch to using a list. `of` >>> could be similarly transformed: >>> >>> to-report of-list [ agent-list reporter ] >>> report map [ [ runresult reporter ] of ? ] agent-list >>> end >>> >>> Called like: of-list agents-with-repeats task [ turtle-variable ] >>> >>> Now `with`: >>> >>> to-report with-list [ agent-list predicate ] >>> report filter [ [ runresult reporter ] of ? ] agent-list >>> end >>> >>> Called like: with-list agents-with-repeats task [ turtle-variable = 5 ] >>> >>> Besides reordering arguments and requiring `task`, these should pretty >>> much be drop-in replacements for their agentset counterparts. As you said, >>> the uniqueness of agents in agentsets is quite baked in. >>> >>> Hope that helps! >>> Bryan >>> >>> On Fri Feb 06 2015 at 10:00:48 AM Marshall <[email protected]> >>> wrote: >>> >> A model I'm working on includes a series of functions that implement >>>> a random choice of turtles that will send messages to another turtle. >>>> Recently, I decided it might be better to allow the selection of senders >>>> to >>>> be random with repeats. Nicolas Payette's rnd extension >>>> <https://github.com/NetLogo/Rnd-Extension> provides a convenient >>>> function that provides this functionality, returning a list that may >>>> contain repeats: weighted-n-of-with-repeats. (Thanks Nicolas!) >>>> >>>> However, converting a list of turtles with repeats into a turtleset >>>> loses the repeats; agentsets contain only unique elements. So if I want >>>> to >>>> allow repeats in the turtles that send messages, I have to rewrite a small >>>> but significant bit of code in different functions, replacing ask's with >>>> loops, etc. >>>> >>>> Question: Might it be useful to allow a new kind of agentset that >>>> allows repeats? It would be useful to me in this situation, but I know >>>> that the idea violates longstanding assumptions about agentsets, and I >>>> suspect that it would also require a lot of changes to the NetLogo source >>>> to implement. >>>> >>>> I thought I'd raise it as a question, anyway, to see what others think. >>>> -- >>>> You received this message because you are subscribed to the Google >>>> Groups "netlogo-devel" group. >>>> >>> To unsubscribe from this group and stop receiving emails from it, >>>> send an email to [email protected]. >>> >>> >>>> For more options, visit https://groups.google.com/d/optout. >>>> >>> -- >> You received this message because you are subscribed to the Google Groups >> "netlogo-devel" group. >> To unsubscribe from this group and stop receiving emails from it, send an >> email to [email protected] <javascript:>. >> For more options, visit https://groups.google.com/d/optout. >> > -- > You received this message because you are subscribed to the Google Groups > "netlogo-devel" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected] <javascript:>. > For more options, visit https://groups.google.com/d/optout. > > > -- You received this message because you are subscribed to the Google Groups "netlogo-devel" group. 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