[kepler-dev] modeling question about producing f(A, x), f(A, y)...

Norbert Podhorszki pnorbert at cs.ucdavis.edu
Fri Aug 3 11:45:20 PDT 2007


Hi Daniel,

Thanks for the idea.
You have generalized the problem here, because for us, A is just one 
single token (a1 in your example).

The collection-oriented modelling seems to be a bit heavy weight solution 
in the sense, that if we start from a Constant with single firing and a 
Ramp to generate a stream of tokens, it seems to be a lot of work to make 
it a collection oriented workflow, isn't it?

Thanks
Norbert


On Fri, 3 Aug 2007, Daniel Zinn wrote:

> Hi,
>
> (let me try, perhaps this might help)
>
> The problem here is that we need to preserve the dependency between A and
> x,y,z... This is a classical use-case for collection-oriented workflows.
>
> You could probably use Tim McPhillips' and Shawn Bowers' collection-oriented
> framework to solve this problem. You could send A as meta-data in a
> collection that contains x,y,z,.... In the third actor you then just pull the
> metadata and the x, ..
>
> You can also emulate a collection by using a workflow with 3 actors in a
> pipeline:
>
> A1 --> A2 --> A3
>
> actor one sends a1,a2,a3...
> A2 consumes a1 and produces a1, x, y, z, ..., a2, x, y, z
> A3's behavior depends on the type of what is coming in:
>     if   input == ai    => store ai in a local variable for later
>     else (input is one of x,y,z,...) => compute f(ai, input) and output
>                                         result (with or without context)
>
> PS:
>
> In a collection oriented / tree-type enabled workflow where inner nodes also
> can contain data, you could do something like that:
>
> Let the three actors be
>
> A1 --> A2 --> A3
>
> A1 produces data of type A*        (that is a list of As)
> A2 produces data of type A[X*]     (that is to each A, also contains a
>                                    list of x,y,z...
>                                    as a new sub collection)
> A3 then has a 'read scope' of A=>a[ X=>x ]
> A3's action then uses a and x.
>
>
> Daniel


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