Hi!
Sorry for spamming the mailing list...
At the moment I am focussing on the 3rd ide of modelling.
Then I have to formulate constraints as
c=j <==> x_{j+u} = v
By substituting i=j-u I get
c=i+u <==> x_i = v
Which looks pretty much like the channel constraint, except that on the right
side there is x_i = v instead of x_i = 1.
Do I need additional (temporary) boolean variables to get rid of this?
Best Regards,
Uwe Nowak
----------------ursprüngliche Nachricht-----------------
Von: "Uwe Nowak" uwe.no...@itwm.fraunhofer.de
An: users@gecode.org
Datum: Sat, 25 May 2013 23:33:18 +0200
-------------------------------------------------
> Hi!
>
> Thank you for your answer. As I stated, I am a beginner to gecode and
> constraint
> programming at all. I did not
> try reification, but by this keyword I managed to solve the problem.
>
>
>
> However, I still think, that I am formulating my constraint in a bad way. I
> managed
> to reduce my
> (sub)problem to the following:
>
> I have an one-dimensional array
> #############
>
> Furthermore, I have patterns such as
> Pattern 1 = aa#a
> Pattern 2 = b#b#b
> where the hash means an empty field.
>
> I want to place these patterns on the array, i.e. possible placements are
> Placement 1: aa#a###b#b#b#
> Placement 2: aabab#b######
>
> No I want to store the position (i.e. the column) of each pattern in an
> IntVarArray
> c, i.e. in Placement 1 it
> is c=(0; 7) in Placement 2 it is c=(0; 2). However I do not know, how to
> formulate the
> non-overlapping.
>
>
> I have three possible Ideas:
> 1. For each pattern I have an BoolVarArray to indicate if the pattern is
> placed
> there
> For Placement 1 I have two arrays (for pattern 1 = 1101000000000) and (for
> Pattern
> 2 = 0000000101010)
> Then I have constraints
> c_a=j <==> x_{j+0} = x_{j+1} = x_{j+3} = 1
> c_b=j <==> y_{j+0} = y_{j+2} = y_{j+4} = 1
>
>
> 2. I have one IntVarArray that stores the pattern placed at this field.
> For Placement 1 this is 1101000202020
> Then I have constraints
> c_a=j <==> x_{j+0} = x_{j+1} = x_{j+3} = 1
> c_b=j <==> x_{j+0} = x_{j+2} = x_{j+4} = 2
>
>
> 3. I assign different numbers to each point of the the pattern, I.e. pattern
> 1 =
> 12#3 and Pattern 2=4#5#6
> For Placement 1 this is 1203000405060
> Then I have constraints
> c_a=j <==> x_{j+0} = 1
> c_a=j <==> x_{j+1} = 2
> c_a=j <==> x_{j+3} = 3
> c_b=j <==> x_{j+0} = 4
> c_b=j <==> x_{j+2} = 5
> c_b=j <==> x_{j+4} = 6
>
> However I am somehow lost, how to formulate such constraints efficiently.
> Although this seems a little bit similar to the Pentomino example, with my
> current gecode-skills I am not
> able to transfer the Ideas.
>
> Best Regards,
> Uwe
>
>
> ----------------ursprüngliche Nachricht-----------------
> Von: "Christian Schulte" cschu...@kth.se
> An: "'Uwe Nowak'" uwe.no...@itwm.fraunhofer.de , users@gecode.org
> Datum: Thu, 23 May 2013 17:49:07 +0200
> -------------------------------------------------
>
>
>> Hi,
>>
>> Did you try reification? While not great, it should not be too hard to pull
>> this off. Or am I missing something here?
>>
>> Best
>> Christian
>>
>> --
>> Christian Schulte, Professor of Computer Science, KTH,
>> www.ict.kth.se/~cschulte/
>>
>>
>> -----Original Message-----
>> From: users-boun...@gecode.org [mailto:users-boun...@gecode.org ] On
>> Behalf
>> Of Uwe Nowak
>> Sent: Thursday, May 23, 2013 3:40 PM
>> To: users@gecode.org
>> Subject: [gecode-users] Problem to formulate a constraint
>>
>> I am a beginner with gecode and have a problem to formulate a constraint.
>> I was looking through all channel constraints, however they do not seem to
>> fit my needs, or I am unable to formulate my needs in the language of the
>> channel constraints.
>>
>> I have the following variables
>> *an IntVar c with a finite set of values {A_1,...,A_n} *an IntVarArray p
>>
>> I have the following fixed parameters
>> For each value A_t I have a finite set of fixed indexed values I_t (e.g, an
>> std::set<int>)
>> A constant B
>>
>> Now I want to formulate the following constraints for(t = 1...n){
>> c=A_t ==> for all I in I_t: p[i]=B
>> }
>>
>>
>> I thought to create an IntVarArgs of the subset of p with the indices I_t
>> However, than I have tor formulated for an IntVarArgs q_t:
>> for(t = 1...n){
>> c=A_t ==> For all elements q_t[i]=B
>> }
>>
>> However, I do not find the right expressions to formulate this in gecode...
>>
>>
>>
>> _______________________________________________
>> Gecode users mailing list
>> users@gecode.org
>> https://www.gecode.org/mailman/listinfo/gecode-users
>>
>>
>
>
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