[ACT-R-users] approximate floating point retrieval

[Alexander Petrov]

Myriam,

These "floating-point values"are not included in standard ACT-R, as far as 
I know. I call them  "magnitudes" and use them extensively in an ACT-R 
model of psychophysical scaling called ANCHOR. Please email me directly 
(apetrov at uci.edu) if you are interested in references or preprints. My 
code, however, is developed outside the ACT-R implementation and is not 
written in Lisp.

Within the standard Lisp implementation, your best bet probably is to 
extend (or redefine?) ACT-R's similarity function and turn partial matching 
on. I've lost track of the details but I'm sure other people on this list 
can advise.

I'm curious what your application is? I mean, in what circumstances do you 
think such floating-point values are necessary.

Hope that helps,
   -- Alexander Petrov


At 08:15 AM 12/4/2003, contractor wrote:

>How to you retrieve a chunk with an approximate floating point value?
>Thanks.
>
>Here's an example code that gives me an error when not retrieving the
>exact value.
>
>(clear-all)
>
>(chunk-type goal state)
>(chunk-type mynum val)
>
>(add-dm (mygoal isa goal state first)
>         (mynum0 isa mynum val 1.48)
>         (mynum1 isa mynum val 1.54)
>         (mynum2 isa mynum val 2.05)
>         (mynum3 isa mynum val 3.5555)
>         (mynum4 isa mynum val 3.68))
>
>(p one
>    =goal>
>    isa goal
>       state first
>    ==>
>    +retrieval>
>      isa mynum
>      val 3.55
>    =goal>
>      state second
>
>
>(p two
>    =goal>
>    isa goal
>       state second
>    =retrieval>
>     isa mynum
>     val =val
>    ==>
>    !output! (=val)
>    =goal>
>       state stop)
>
>(goal-focus mygoal)
>
>(sgp :er t :v t)
>
>
>
>
>--
>
>Myriam Abramson, Ph.D.
>ITT Industries, Inc.
>202-404-7342
>
>
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