Example usage for org.apache.commons.math3.optimization.linear Relationship LEQ

Introduction

In this page you can find the example usage for org.apache.commons.math3.optimization.linear Relationship LEQ.

Prototype

Relationship LEQ

To view the source code for org.apache.commons.math3.optimization.linear Relationship LEQ.

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Document

Lesser than or equal relationship.

Usage

From source file:eu.smartenit.sbox.eca.ReferenceVectorCalculator.java

/**
 * Calculates the reference vector using simplex method.
 * /* w  ww. j  ava 2s.c o m*/
 * @param S1 The DC traffic manipulation freedom 
 * @param S2 The DC traffic manipulation freedom 
 * @param aList The list of candidate areas
 * @param sourceAsNumber The number of the source AS
 * @return Returns an RVector containing the reference vector values.
 */
private LocalRVector calculateReferenceVector(double[] S1, double[] S2, List<Area> aList, int sourceAsNumber) {
    List<PointValuePair> solutionList = new ArrayList<PointValuePair>();
    for (Area a : aList) {

        Long x1Lower = a.getD1().getLowerBound(); // Corresponds to alpha1i
        Long x1Upper = a.getD1().getUpperBound(); // Corresponds to alpha1i+1
        Long x2Lower = a.getD2().getLowerBound(); // Corresponds to alpha2i
        Long x2Upper = a.getD2().getUpperBound(); // Corresponds to alpha2i+1

        Segment segment1 = costFunctionMap1.get(x1Lower); // Corresponds to the suitable cf segment for alpha1
        Segment segment2 = costFunctionMap2.get(x2Lower); // Corresponds to the suitable cf segment for alpha2

        // Function    f:  f1(x1) + f2(x2) + c //c corresponds to the sum of the constant part of f1 and f2
        // Constraints c1: x1       >  alpha1i
        //             c2: x1       <= alpha1i+1 
        //             c3:      x2  >  alpha2j
        //             c4:      x2  <= alpha2j+1
        //             c5: x1 + x2  == X_V[x1] + X_V[x2]
        //            c6: x1       >= X_V[x1] + S1[x1]
        //             c7: x1       <= X_V[x1] + S2[x1]
        //             c8: x2       >= X_V[x2] + S2[x2]
        //              c9: x2       <= X_V[x2] + S1[x2]

        LinearObjectiveFunction f = new LinearObjectiveFunction(
                new double[] { segment1.getB(), segment2.getB() }, (segment1.getA() + segment2.getA())); //f1(x1) + f2(x2)
        Collection<LinearConstraint> constraints = new ArrayList<LinearConstraint>();
        constraints.add(new LinearConstraint(new double[] { 1, 0 }, Relationship.GEQ, x1Lower.doubleValue()));
        constraints.add(new LinearConstraint(new double[] { 1, 0 }, Relationship.LEQ, x1Upper.doubleValue()));
        constraints.add(new LinearConstraint(new double[] { 0, 1 }, Relationship.GEQ, x2Lower.doubleValue()));
        constraints.add(new LinearConstraint(new double[] { 0, 1 }, Relationship.LEQ, x2Upper.doubleValue()));
        constraints.add(new LinearConstraint(new double[] { 1, 1 }, Relationship.EQ, X_V[x1] + X_V[x2]));
        constraints.add(new LinearConstraint(new double[] { 1, 0 }, Relationship.GEQ, X_V[x1] + S1[x1]));
        constraints.add(new LinearConstraint(new double[] { 1, 0 }, Relationship.LEQ, X_V[x1] + S2[x1]));
        constraints.add(new LinearConstraint(new double[] { 0, 1 }, Relationship.GEQ, X_V[x2] + S2[x2]));
        constraints.add(new LinearConstraint(new double[] { 0, 1 }, Relationship.LEQ, X_V[x2] + S1[x2]));

        try {
            PointValuePair solution = new SimplexSolver().optimize(f, constraints, GoalType.MINIMIZE, true);
            solutionList.add(solution);

            double x = solution.getPoint()[0];
            double y = solution.getPoint()[1];
            double value = solution.getValue();
            logger.info("\n");
            logger.info("Area [" + x1Lower + ", " + x1Upper + ", " + x2Lower + ", " + x2Upper + "]");
            logger.info("Cost function: " + segment1.getB() + "x1 " + segment2.getB() + "x2 " + " + "
                    + (segment1.getA() + segment2.getA()));
            logger.info("Reference vector x1=" + x + " x2=" + y + " f1(x1) + f2(x2)=" + value);
        } catch (NoFeasibleSolutionException e) {
            logger.info("\n");
            logger.info("Area [" + x1Lower + ", " + x1Upper + ", " + x2Lower + ", " + x2Upper + "]");
            logger.info("Cost function: " + segment1.getB() + "x1 " + segment2.getB() + "x2 " + " + "
                    + (segment1.getA() + segment2.getA()));
            logger.error("No feasible solution found: for area " + a);
        }

    }

    PointValuePair minimalSolution = getMinimalSolution(solutionList);
    LocalRVector referenceVector = constructReferenceVector(minimalSolution, sourceAsNumber);

    logger.info("Chosen reference vector: " + referenceVector.getVectorValues().get(0).getValue() + " "
            + referenceVector.getVectorValues().get(1).getValue());

    return referenceVector;
}

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