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Re: [Choco-users] solveAll() bug?
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From: Varun J. <jai...@ho...> - 2006-11-18 00:34:44
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Hi again,I thought I should give you my test code so that you can run it yo=
urself. I have included the code at the bottom. Note that the CSP problem I=
was experimenting with has changed a bit (however, the strange behaviour s=
till remains) Heres the new CSP problem:Variables:Variable0, Domain: {4, 2}=
Variable1, Domain: {5, 1, 4}Variable2, Domain: {3, 4, 6}Variable3, Domain: =
{1, 2}Variable4, Domain: {7, 8, 6, 1}Constraints:Constraint0, on variables =
3 , Allowed tuples:1Constraint1, on variables 2, 4 , Allowed tuples:6, 7Con=
straint2, on variables 2 , Allowed tuples:34Constraint3, on variables 4, 1 =
, Allowed tuples:7, 18, 16, 51, 5Heres the output of running the program gi=
ven below:Choco Solutions2, 1, 3, 1, 8, 4, 1, 3, 1, 8, As you can see, none=
of the solutions satisfy constraint1. Still choco returns these solutions.=
Heres my code (BTW, Thanks for taking time out to help me.. I really apprec=
iate it :-)):import choco.Problem;import choco.Constraint;import choco.inte=
ger.IntDomainVar;import choco.integer.IntVar;import java.util.ArrayList;/**=
* @author Varun Jain (vj) * @version $Revision$, $Date$ * @created Nov 17,=
2006 */public class ChocoTest { public static void main(String args[]) { =
Problem chocoCSP =3D new Problem(); IntDomainVar[] vars =3D new IntDo=
mainVar[5]; Constraint[] cons =3D new Constraint[4]; //-----Construct=
all variables int id =3D 0; vars[id] =3D chocoCSP.makeEnumIntVar("v"=
+ id++, new int[]{4, 2}); vars[id] =3D chocoCSP.makeEnumIntVar("v" + id=
++, new int[]{5, 1, 4}); vars[id] =3D chocoCSP.makeEnumIntVar("v" + id++=
, new int[]{3, 4, 6}); vars[id] =3D chocoCSP.makeEnumIntVar("v" + id++, =
new int[]{1, 2}); vars[id] =3D chocoCSP.makeEnumIntVar("v" + id++, new i=
nt[]{7, 8, 6, 1}); id =3D 0; ArrayList<int[]> tuples; //-----Now c=
onstruct all constraints //-----Constraint0 tuples =3D new ArrayList<=
int[]>(); tuples.add(new int[]{1}); cons[id] =3D chocoCSP.makeTupleFC=
(new IntVar[]{vars[3]}, tuples, true); chocoCSP.post(cons[id++]); //-=
----Constraint1=0A=
tuples =3D new ArrayList<int[]>(); tuples.add(new int[]{6, 7}); c=
ons[id] =3D chocoCSP.makeTupleFC(new IntVar[]{vars[2], vars[4]}, tuples, tr=
ue); chocoCSP.post(cons[id++]); //-----Constraint2=0A=
tuples =3D new ArrayList<int[]>(); tuples.add(new int[]{3}); tupl=
es.add(new int[]{4}); cons[id] =3D chocoCSP.makeTupleFC(new IntVar[]{var=
s[2]}, tuples, true); chocoCSP.post(cons[id++]); //-----Constraint3=
=0A=
tuples =3D new ArrayList<int[]>(); tuples.add(new int[]{7, 1}); t=
uples.add(new int[]{8, 1}); tuples.add(new int[]{6, 5}); tuples.add(n=
ew int[]{1, 5}); cons[id] =3D chocoCSP.makeTupleFC(new IntVar[]{vars[4],=
vars[1]}, tuples, true); chocoCSP.post(cons[id++]); //-----Now get s=
olutions System.out.println("Choco Solutions"); if(chocoCSP.solve() =
=3D=3D Boolean.TRUE) { do { for(int i =3D 0; i < chocoCSP.getNb=
IntVars(); i ++) { System.out.print(((IntDomainVar)chocoCSP.getInt=
Var(i)).getVal() + ", "); } System.out.println(); } whil=
e(chocoCSP.nextSolution() =3D=3D Boolean.TRUE); } }}> Date: Sat, 18 Nov=
2006 00:28:23 +0100> From: Gui...@em...> To: choco-users@lists=
.sourceforge.net> Subject: Re: [Choco-users] solveAll() bug?> > Hi,> > This=
strange behavior is due to the fact that you use SolveAll() before > Solve=
(). SolveAll() and Solve()+nextSolution()'s loop are equivalents > (in o=
ther words you search for all the solutions twice), so usually we > don't =
do that :) What do you want to do ?> > -Guillaume> > Varun Jain a =E9crit :=
> > Hi,> >> > Thank you very much for your quick reply. I guess the real qu=
estion I > > wanted to ask was that if choco could return results even when=
the > > problem is infeasible. I did my experiment with the following prob=
lem:> >> > ------------------------------------------------> > Variables:> =
> Variable0, Domain: {3, 1, 4}> > Variable1, Domain: {2, 4, 6}> > Variable2=
, Domain: {2, 1}> > Variable3, Domain: {3, 1}> > Variable4, Domain: {6, 2, =
5}> >> > Constraints:> > Constraint0, on variables 2 , Allowed values:> > 2=
> > Constraint1, on variables 2, 4 , Allowed values:> > 1, 6> > 2, 2> > Con=
straint2, on variables 4, 2 , Allowed values:> > 5, 2> > Constraint3, on va=
riables 1, 3 , Allowed values:> > 2, 3> > ---------------------------------=
---------------------> >> > All the constraints were created using Problem.=
makeTupleFC(IntVar[] > > varList, ArrayList tuples, boolean feasible). For =
example, the first > > constraint can be created as follows:> >> > --------=
----------------------------------> > Problem chocoCSP;> > /**> > * Set up=
the variables using chocoCSP.makeEnumIntVar()> > */> > IntVar[] varList =
=3D new IntVar[1];> > varList[0] =3D variables[2];> > ArrayList<int[]> tupl=
es =3D new ArrayList<int[]>();> > tuples.add(new int[]{2});> > chocoCSP.mak=
eTupleFC(varList, tuples, true);> > ---------------------------------------=
----------> >> > To obtain solutions, I did the following:> >> > ----------=
-------------------------------------> > System.out.println("SolveAll s=
ays: " + chocoCSP.solveAll());> > System.out.println("isFeasible says: =
" + chocoCSP.isFeasible());> > System.out.println("Choco Solutions");> =
> if(chocoCSP.solve() =3D=3D Boolean.TRUE) {> > do {> > f=
or(int i =3D 0; i < chocoCSP.getNbIntVars(); i ++) {> > System.ou=
t.print(((IntDomainVar) > > chocoCSP.getIntVar(i)).getVal() + ", ");> > =
}> > System.out.println();> > } while(chocoCSP.nextSolut=
ion() =3D=3D Boolean.TRUE);> > }> > -----------------------------------=
------------> >> > Here is the output:> >> > SolveAll says: true> > isFeasi=
ble says: false> > Choco Solutions> > 1,2,2,3,5,> > 3,2,2,3,5,> > 4,2,2,3,5=
,> >> >> > Clearly, the solutions do not satisfy all the constraints. For >=
> instance, none of the solutions satisfy Constraint1. Is this expected > =
> behaviour??> >> > Thanks again,> > -Varun.> >> >> >> >> > ---------------=
---------------------------------------------------------> > > Date: Fri, 1=
7 Nov 2006 11:31:40 +0100> > > From: Gui...@em...> > > To: jain=
_v...@ho...> > > Subject: Re: [Choco-users] solveAll() bug?> > >> > =
> Hi,> > >> > > I am not sure to understand what you try to do but i have s=
ome > > answers :)> > > -SolveAll still return true (it is hardcoded) but y=
ou can modify the> > > function solveAll() in choco.Problem> > >> > > In ch=
oco.Problem:> > > public Boolean solveAll() {> > > solver.firstSolution =3D=
false;> > > solver.generateSearchSolver(this);> > > solver.launch();> > > =
return Boolean.TRUE;> > > }> > >> > > -What kind of error do you have ? How=
do you implement the> > > nextSolution() loop ?> > > BTW, if you use nextS=
olution() to display solutions, you can use > > instead:> > >> > > "Solver.=
setVerbosity(Solver.SOLUTION);" before to begin to solve> > > and "Solver.f=
lushLogs();" to print solutions> > >> > > else:> > >> > > if (pb.solve() =
=3D=3D Boolean.TRUE) {> > >> > > do {> > > //Code> > > }> > > } while(pb.ne=
xtSolution() =3D=3D Boolean.TRUE);> > > }> > >> > >> > > I hope it helps yo=
u... :)> > > -Guillaume> > >> > > Varun Jain a =E9crit :> > > > Hi..> > > >=
Is there any reason why the solveAll() method will return true > > even if=
> > > > there is no solution that satisfies all constraints. I was getting>=
> > > this behaviour so I did a little experiment: I set up a simple > > p=
roblem> > > > and executed the following:> > > >> > > > Problem chocoCSP;> =
> > > //...............> > > > //-----Set up the problem> > > > //.........=
......> > > > System.out.println("SolveAll says: " + chocoCSP.solveAll());>=
> > > System.out.println("isFeasible says: " + chocoCSP.isFeasible());> > =
> >> > > > The following was the output> > > >> > > > SolveAll says: true> =
> > > isFeasible says: false> > > >> > > > I thought solveAll() returns fal=
se if no solution exists. Also, for> > > > this problem, the solutions I ge=
t from the nextSolution() method do> > > > not satisfy all constraints. Any=
explainations would be really > > helpful?> > > >> > > > Thanks,> > > > -V=
arun.> > >> > -------------------------------------------------------------=
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