[gecode-users] using MaximizeScript to find the optimal solution

[Christian Schulte]

You really need to read MPG: BAB also returns several solutions (if you use
it that way). The one found last is best.

 

Christian

 

--

Christian Schulte, Professor of Computer Science, KTH,
www.ict.kth.se/~cschulte/

 

From: users-bounces at gecode.org [mailto:users-bounces at gecode.org] On Behalf
Of naguissa light
Sent: Tuesday, December 03, 2013 3:34 PM
To: Guido Tack
Cc: users at gecode.org list
Subject: Re: [gecode-users] using MaximizeScript to find the optimal
solution

 

Thank you very much for your answer.

So to find all the feasable solution of a model i just use DFS 

when i want to find the optimal solution of the objectiv function of the
model i use BAB 

my question here : is it normal to find more then one optimal solution to
the objective function of my model?????

Thank you very much 

Naguissa

 

2013/12/3 Guido Tack <tack at gecode.org>

Hi,

 

I don't think I understand your question.  Whether you inherit from Space or
from MaximizeScript shouldn't make any difference to the number of solutions
when using DFS.

In order to enumerate all optimal solutions, you first have to run a BAB to
get the value of the objective, and then run another search for all
solutions using DFS, where you post an additional constraint to set the
objective to that optimal value.

 

Cheers,

Guido

 

-- 

Guido Tack

http://www.csse.monash.edu/~guidot/

 

 

 

On 3 Dec 2013, at 1:40 pm, naguissa light <naguissa1989 at gmail.com> wrote:

 

I was wondring about that because when i try to get just one feasable
solution for my model i used Space ( the numbre of feasable solutions are
48) so when i try to get the optimal solution for my model i used
MaximizeScript and i get 1140 solutions !!!!!!!!!!!! is that normal ????,,

Did i miss any thing here???

Thank You for your help

Naguissa

 

2013/12/3 naguissa light <naguissa1989 at gmail.com>

 

hi all!

i want in my model to find the optimal solution so when i read the MPG i
find that i have to use MaximizeScript ( to maximize the objective function)
so what i want to know is : is it possible to find more then one optimal
solution when using MaximizeScript ????????



Thank you for your help 


Naguissa

 

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