Returning a subset of possible solutions

[alhambra1]

Hi,

Is there a way to retrieve a subset of optimal solutions rather than just one? If you could even point me towards where to look to possibly tweak to accomplish that, that would be great.

Sincerely,

[JWally]

Are you looking for a subset of mixed-integer-LPs or just plain LP's?

[alhambra1]

At the moment, I'm using it with integers only.

On Mon, 28 Oct 2019, 9:54 pm Justin Wolcott, notifications@github.com wrote:

Are you looking for a subset of mixed-integer-LPs or just plain LP's?

— You are receiving this because you authored the thread. Reply to this email directly, view it on GitHub https://github.com/JWally/jsLPSolver/issues/93?email_source=notifications&email_token=AANRFJPGLA3PUSH7SN6LLETQQ6JUXA5CNFSM4JAFS4GKYY3PNVWWK3TUL52HS4DFVREXG43VMVBW63LNMVXHJKTDN5WW2ZLOORPWSZGOECO62AI#issuecomment-547220737, or unsubscribe https://github.com/notifications/unsubscribe-auth/AANRFJJ2AGYSLANQQOV6KMLQQ6JUXANCNFSM4JAFS4GA .

[JWally]

https://github.com/JWally/jsLPSolver/blob/be561df57cc6cea45ad828b0dfc22cdc903c3c7f/src/Tableau/branchAndCut.js#L162-L175

This if block, between 161 and 175 is where the MILP has a valid solution. You could add the following bit of code there:

            //
            //
            //
            //
            //
            //
            var nowSolution = (this.model.tableau.getSolution());
            var store = nowSolution.generateSolutionSet();
            store.result = nowSolution.evaluation;

            if(!this.model.solutions){
                this.model.solutions = [];
            }

            this.model.solutions.push(store);
            //
            //
            //
            //
            //
            //
            //

and access them like this:

        var a = solver.Solve(model,1e-8,true);
        console.log(a._tableau.model.solutions);

[alhambra1]

Thank you so much. I really appreciate it!

On Wed, 30 Oct 2019 at 15:43, Justin Wolcott notifications@github.com wrote:

https://github.com/JWally/jsLPSolver/blob/be561df57cc6cea45ad828b0dfc22cdc903c3c7f/src/Tableau/branchAndCut.js#L162-L175

This if block, between 161 and 175 is where the MILP has a valid solution. You could add the following bit of code there:

        //
        //
        //
        //
        //
        //
        var nowSolution = (this.model.tableau.getSolution());
        var store = nowSolution.generateSolutionSet();
        store.result = nowSolution.evaluation;

        if(!this.model.solutions){
            this.model.solutions = [];
        }

        this.model.solutions.push(store);
        //
        //
        //
        //
        //
        //
        //

and access them like this:

    var a = solver.Solve(model,1e-8,true);
    console.log(a._tableau.model.solutions);

— You are receiving this because you authored the thread. Reply to this email directly, view it on GitHub https://github.com/JWally/jsLPSolver/issues/93?email_source=notifications&email_token=AANRFJM5M7K5ZE4VCAIU2UDQRHPVHA5CNFSM4JAFS4GKYY3PNVWWK3TUL52HS4DFVREXG43VMVBW63LNMVXHJKTDN5WW2ZLOORPWSZGOECVQYUI#issuecomment-548080721, or unsubscribe https://github.com/notifications/unsubscribe-auth/AANRFJLLTUBJNMYCEWM4H7TQRHPVHANCNFSM4JAFS4GA .

[JWally]

FWIW, it doesn't seem to slow down the solver too much; so its an option you can get at through:

{
    "options": {
        "keep_solutions": true
    }
}

which puts the solutions on _tableau.model.solutions.

Next update I send, it'll be in there :-)

Hope it helps!