RE: Counting backtracks

Farouk,

Are you remembering to count the backtracks in your labelling code? As it 
looks as if the B is uninstantiated. If so, can you send me a bigger 
fragment of code to study.

Karen

>X-MimeOLE: Produced By Microsoft Exchange V6.0.6249.0
>content-class: urn:content-classes:message
>MIME-Version: 1.0
>Subject: RE: [eclipse-users] Counting backtracks
>Date: Fri, 2 May 2003 15:32:31 +0100
>Thread-Topic: [eclipse-users] Counting backtracks
>Thread-Index: AcMQof3V3KhXX1AUS/GvTHGCiL33JQAFbMiA
>From: "Aminu, Farouk" <f.aminu@lancaster.ac.uk>
>To: Joachim Schimpf <j.schimpf@icparc.ic.ac.uk>, eclipse-users 
<eclipse-users@icparc.ic.ac.uk>
>X-OriginalArrivalTime: 02 May 2003 14:32:31.0921 (UTC) 
FILETIME=[AA543210:01C310B7]
>Content-Transfer-Encoding: 8bit
>X-MIME-Autoconverted: from quoted-printable to 8bit by zeus.hud.ac.uk id 
PAA05198
>
>Hello,
>
>I used: 
>
> minimize((
>	    mylabeling(SearchVars),
>            get_backtracks(B),
>            printf("Backtracks to this point = %d \n \n", [B])
>	), OptimalNumber)
>
>but I am getting the following message:
>
>'type error in printf("%d \n \n", [B])'
>
>am I doing something wrong?
>
>Farouk
>
>Umaru Farouk Aminu
>Department of Management Science,
>Lancaster University,
>Lancaster,
>LA1 4YX,
>UK.
>Tel: +44 1524 383619 (Home)
>      +44 1524 593865 (School)
>      +44 1524 844885 (Fax)
>
>
>
>
>-----Original Message-----
>From: Joachim Schimpf [mailto:j.schimpf@icparc.ic.ac.uk]
>Sent: 02 May 2003 12:40
>To: eclipse-users@icparc.ic.ac.uk
>Subject: Re: [eclipse-users] Counting backtracks
>
>
>Karen Petrie (scomkep@zeus.hud.ac.uk) wrote
>>...
>> Then you need to redefine the event handler:
>> 
>> write_info(_Error, Predicate):-
>>         arg(1, Predicate, Minimum),
>>         printf("Found a solution with cost %d \n", [Minimum]),
>>         get_backtracks(B),
>>         printf("Backtracks to this point = %d \n \n", [B]).
>> 
>> %set event handler
>> :- set_event_handler(280, write_info/2).
>> 
>> Then all you do is call minimize on your labelling:
>> 
>> minimize(mylabeling(SearchVars), OptimalNumber)
>
>
>There is actually no need to use this obscure event handler.
>You can simply write:
>
>    minimize((
>	    mylabeling(SearchVars),
>            get_backtracks(B),
>            printf("Backtracks to this point = %d \n \n", [B])
>	), OptimalNumber)
>
>Whenever mylabeling/1 succeeds, you have a better solution.
>
>
>-- 
> Joachim Schimpf              /             phone: +44 20 7594 8187
> IC-Parc                     /      mailto:J.Schimpf@imperial.ac.uk
> Imperial College London    /    http://www.icparc.ic.ac.uk/eclipse
>
>