From: Marc van Dongen <dongen_at_cs.ucc.ie>

Date: Wed 07 Aug 2002 08:22:54 AM GMT

Message-ID: <20020807092254.N515@cs.ucc.ie>

Date: Wed 07 Aug 2002 08:22:54 AM GMT

Message-ID: <20020807092254.N515@cs.ucc.ie>

Sorry about the delay in replying. We've had a power cut over the weekend and mail is comming in slowly. Warwick Harvey (wh@icparc.ic.ac.uk) wrote: : What is it about minimize's behaviour that you would like to change, in : order to try to exploit this? If minimize( labeling( VARS ), EXPR ) results in a valid labeling and cost COST, then it will post the constraint EXPR < COST and will search for new solutions to labeling( VARS ). If constraint propagation forces the domain of EXPR to be such that COST - 1, COST -2, ..., COST - N + 1 are no longer in it, then I would like to stop. Especially if EXPR has many values in its domain, this may save a lot. : Note that if a solution has been found with cost COST, then minimize : proceeds to search for a solution with *any* cost less than COST. If it : proceeded to try cost = COST-1, etc., then yes, one could stop when COST-N : had no solution, but that's not the way it works (because in general that's : not a particularly smart way to do it). I know it's not the way it works. That's why I asked if it's possible to do it differently:-) : Is there some way of determining that COST-1 through COST-N have no solution : that would be significantly cheaper than just looking for anything less than : COST-1? I believe that near an almost optimal solution it is far more cheaper to find a solution with cost between COST-1 and COST-N or to prove that such solution does not exist. That's why I'm so interested in it. Regards, MarcReceived on Wed Aug 07 09:26:18 2002

*
This archive was generated by hypermail 2.1.8
: Wed 16 Nov 2005 06:07:16 PM GMT GMT
*