[AccessD] miracle required apparently

[Steve Schapel]

Thanks, Paul.

Your illustration didn't come through to me, but I think I've got the 
idea.

Ideally and conceptually, we would have every combination of 
participants for every time/activity slot unique.

However, achieving that in most instances seems like a dreamland wish, 
and is therefore a lower priority. So on that score, I think we are 
shooting for minimising, rather than eliminating, crossover combinations 
wherever possible.

The other specifications, i.e. a participant can't be assigned to more 
than one activity in the same timeslot, and a participant can't be 
assigned to the same activity more than once, are obviously stricter 
requirements.

Regards
Steve


On 21/10/2023 10:10:03 pm, "Paul Hartland via AccessD" 
<accessd at databaseadvisors.com> wrote:

>Hi Steve,
>
>At work and just thought of a quick question about this not having the same
>group of participants in any other time/activity slot, your example in the
>previous email shows just two participants in each time/activity slot, what
>if we have upto four participants in each time\activity slot can any of
>them be put together again as in the example below or regardless of
>participants every time slot/activity has to be unique, forgive the very
>quick excel snapshot, but hopefully will give you an idea of what I am on
>about would the 09:30 time slot activity A1 be allowed, I am assuming not
>at the moment while at work 😀
>
>[image: image.png]
>
>Paul
>
>
>
>
>
>On Sat, 21 Oct 2023 at 08:38, Steve Schapel <
>steve at datamanagementsolutions.biz> wrote:
>
>>  Thanks, Stuart.
>>
>>  Mixing them up is definitely not impossible, e.g.
>>       AE-CF-DG-BH
>>       CG-AH-BE-DF
>>       DH-BG-AF-CE
>>       BF-DE-CH-AG
>>
>>  However, achieving that programmatically, where the number of
>>  participants, number of activities, and participants per activity are
>>  variables, is what's doing my head in.
>>
>>  Anyway, for us, the option to avoid the same participants together in
>>  the same activity is not a hard requirement - though minimising it is
>>  desirable.
>>
>>  Regards
>>  Steve
>>
>>
>>  On 21/10/2023 8:00:44 pm, "Stuart McLachlan" <stuart at lexacorp.com.pg>
>>  wrote:
>>
>>  >The trivial solution to that one is to put the same participants together
>>  in every slot
>>  >
>>  >i.e
>>  >
>>  >AB-CD-EF-GH
>>  >CD-EF-GH-AB
>>  >EF-GH-AB-CD
>>  >GH-AB-CD-EF
>>  >
>>  >When you don't want AB or CD etc to be paired in more than one event is
>>  where it gets
>>  >tricky (impossible?).
>>  >
>>  >
>>  >
>>  >On 21 Oct 2023 at 6:05, Steve Schapel wrote:
>>  >
>>  >>  Thanks for your comment, Bill.
>>  >>
>>  >>  So, given that there will always be enough slots (number of activities
>>  >>  * number of participants per activity) to accommodate all participants
>>  >>  at any given time ... are you of the opinion that (leaving aside for
>>  >>  now how we arrive at the solution), there should always be a solution
>>  >>  possible - such that participants can be assigned to activities over a
>>  >>  number of sessions in such a way that no particpant will do the same
>>  >>  activity more than once?
>>  >>
>>  >>  It seems to me that the answer must be 'yes', but I confess that my
>>  >>  only evidence for this is "gut feel".
>>  >>
>>  >>  Regards
>>  >>  Steve
>>  >>
>>  >>  On 21/10/2023 6:09:05 pm, "Bill Benson" <bensonforums at gmail.com>
>>  >>  wrote:
>>  >>
>>  >>  >I don´t think this problem generalizes. The reason I say this is
>>  >>  >that the parameters are just integers and no constraints except for
>>  >>  >the very arbitrary facts that you have just enough sessions and just
>>  >>  >fee enough activities to be successful- by brute force.
>>  >>  >
>>  >>  >On Sat, Oct 21, 2023 at 12:12 AM Stuart McLachlan
>>  >>  ><stuart at lexacorp.com.pg> wrote:
>>  >>  >
>>  >>  >>  Ah, I was thinking of something like a  sports series where one
>>  >>  >>  player or team played against a different player or team (i.e. two
>>  >>  >>  participants per match) Where the "pigeonholes" are dates or times
>>  >>  >>   and venues. . Now I'm thinking of something like a military
>>  >>  >>  selection board where you can have say 30 candidates  where you
>>  >>  >>  want to put them through 5 different activities so you split them
>>  >>  >>  into 6 teams of  5 for the first activity and then into different
>>  >>  >>  team compositions for the next activity etc  where the objective
>>  >>  >>  is to mix the teams up for each activity. i.e. have the minimum
>>  >>  >>  number of people together in the same team  for different
>>  >>  >>  activities,
>>  >>  >>
>>  >>  >>  Is that more along the lines of what you are doing?
>>  >>  >>
>>