RE: Unclamped, one shot, pattern presentation

["Mariano Bruno" <bruno@ifir.ifir.edu.ar>]

Thank you very much Kenk.

But...there is not an easy way of doing this? I mean within the PDP++?
Anybody knows?

-----Mensaje original-----
De: kenkwok <kenkwok@cmu.edu>
Para: Mariano Bruno <bruno@ifir.ifir.edu.ar>
CC: pdp-discuss@psych.colorado.edu <pdp-discuss@psych.colorado.edu>
Fecha: miércoles 21 de agosto de 2002 14:58
Asunto: Re: Unclamped, one shot, pattern presentation


>You need to write yr own code.  I modified CsUnitSpec::Compute_Net(Unit*
>u) as follows:
>
>void KcsUnitSpec::Compute_Net(Unit* u, int cycle) {
>  KcsUnit* ku = (KcsUnit*)u;
>  if(ku->lesioned) return;      // do not process if unit lesioned
>
>  ClampType ct = clamp_type;
>  if(clamp_type == HARD_THEN_SOFT_CLAMP) {
>    if( cycle > n_hard) {
>      ct = SOFT_CLAMP;
>      }
>    else {
>      ct = HARD_CLAMP;
>      }
>  }
>
>  if(ct == HARD_CLAMP) {
>    if(ku->ext_flag & Unit::EXT) // no point in computing net for
>clamped units!
>      return;
>    Compute_Net_impl(u);
>  }
>  else {   // soft clamping (or hard-then-soft), always compute net
>    Compute_Net_impl(u);
>    if(ct == SOFT_CLAMP)
>      ku->net += clamp_gain * ku->ext;
>  }
>}
>
>This defines a parameter n_hard which determines how many cycles the
>pattern shd be clamped before releasing the clamping.
>
>
>Mariano Bruno wrote:
>
>>  Hi PDPers:I am trying to explore the hopfield model and its dinamic
>> behavior.ONe of the problems I face for achive an oscillatory or
>> chaotic regime is the next: I can't found anyway to un-clamp the input
>> pattern. I mean, I would like to present only for an instant the
>> pattern and then taking it out. In that way I could observe the
>> dinamic evolution of the "isolated" network.Is there anyway for this
>> kind of patter presentation, as a "one shot" in the PDP++?I will be
>> very helpfull to anybody who could provide this info.Thanks