Ejemplo n.º 1
0
  public double solve(Instance ins, Solution sol, int timeout) throws IloException {
    IloCplex solver = new IloCplex();
    BiIndexedIntVarMap y = new BiIndexedIntVarMap(solver, 0, 1, "y"); // (k,v)   (cluster,node)
    IndexedNumVarMap d =
        new IndexedNumVarMap(solver, 0, Double.MAX_VALUE, "dp"); // (k)     (cluster)	
    TriIndexedNumVarMap f =
        new TriIndexedNumVarMap(solver, 0, Double.MAX_VALUE, "f"); // (k,i,j) (cluster,tail,head)
    BiIndexedIntVarMap r = new BiIndexedIntVarMap(solver, 0, 1, "r"); // (k,i)   (cluster,node
    BiIndexedNumVarMap w = new BiIndexedNumVarMap(solver, 0, 1, "w"); // (i,j)   (node1<node2)

    int superRoot = ins.getNumNodes();
    // compute the weights of the objective function
    double w1 = ins.getW1() / ins.getNumNodes();
    double w2 = ins.getW2() / (ins.getLambda() * ins.getMaxClusterNumber());
    double w3 =
        2
            * ins.getW3()
            / (ins.getNumNodes() * (ins.getNumNodes() - 1) * (ins.getDMax() - ins.getDMin()));

    Set<OrderedPair> fp = new TreeSet<OrderedPair>(ins.getP());
    if (isActiveExtension(Extension.PFILTER)) {
      fp = ins.filterP();
      System.out.println("PFILTER: " + (ins.getP().size() - fp.size()) + " pairs filtered");
    }

    // compute the objective function expression
    IloNumExpr expr = solver.numExpr();

    // O1
    IloNumExpr exprO1 = solver.numExpr();
    for (int i = 0; i < ins.getNumNodes(); ++i) {
      expr = solver.numExpr();
      expr = solver.sum(expr, 1);
      for (int k = 0; k < ins.getMaxClusterNumber(); ++k) expr = solver.diff(expr, y.get(k, i));
      exprO1 = solver.sum(exprO1, solver.prod(w1, expr));
    }
    // O2
    IloNumExpr exprO2 = solver.numExpr();
    for (int k = 0; k < ins.getMaxClusterNumber(); ++k) {
      exprO2 = solver.sum(exprO2, solver.prod(w2, d.get(k)));
    }
    // O3
    IloNumExpr exprO3 = solver.numExpr();
    for (OrderedPair p : fp) {
      double dmax = ins.getDMax();
      double dist = ins.getD(p.i, p.j);
      IloNumVar wvar = w.get(p.i, p.j);
      exprO3 = solver.sum(exprO3, solver.prod(w3 * (dmax - dist), wvar));
    }
    expr = solver.sum(exprO1, solver.sum(exprO2, exprO3));
    solver.add(solver.objective(IloObjectiveSense.Minimize, expr));

    // packing constraints
    for (int i = 0; i < ins.getNumNodes(); ++i) {
      expr = solver.numExpr();
      for (int k = 0; k < ins.getMaxClusterNumber(); ++k) expr = solver.sum(expr, y.get(k, i));
      solver.addLe(expr, 1);
    }

    // root uniqueness constraints
    for (int k = 0; k < ins.getMaxClusterNumber(); ++k) {
      expr = solver.numExpr();
      for (int i = 0; i < ins.getNumNodes(); ++i) expr = solver.sum(expr, r.get(k, i));
      solver.addLe(expr, 1);
    }

    // f,y linking constraints

    // OUT
    for (int k = 0; k < ins.getMaxClusterNumber(); ++k) {
      for (int i = 0; i < ins.getNumNodes(); ++i) {
        expr = solver.numExpr();
        for (Integer j : ins.getOutcut(i)) {
          expr = solver.sum(expr, f.get(k, i, j));
        }
        expr = solver.diff(expr, solver.prod(ins.getMaxClusterSize() - 2, y.get(k, i)));
        solver.addLe(expr, 0);
      }
    }

    // f,r linking constraints
    for (int k = 0; k < ins.getMaxClusterNumber(); ++k) {
      for (int i = 0; i < ins.getNumNodes(); ++i) {
        solver.addLe(f.get(k, superRoot, i), solver.prod(ins.getMaxClusterSize(), r.get(k, i)));
      }
    }

    //		//flow generation constraints
    //		for(int k=0;k<ins.getMaxClusterNumber();++k){
    //			expr=solver.numExpr();
    //			for(int i=0;i<ins.getNumNodes();++i){
    //				expr=solver.sum(expr,f.get(k,superRoot,i));
    //				expr=solver.diff(expr, y.get(k, i));
    //			}
    //			solver.addEq(expr, 0);
    //		}

    // flow conservation constraints
    for (int k = 0; k < ins.getMaxClusterNumber(); ++k) {
      for (int i = 0; i < ins.getNumNodes(); ++i) {
        expr = solver.numExpr();
        for (Integer j : ins.getOutcut(i)) {
          expr = solver.diff(expr, f.get(k, i, j));
          expr = solver.sum(expr, f.get(k, j, i));
        }
        // i can receive flow also from the super root
        expr = solver.sum(expr, f.get(k, superRoot, i));
        solver.addEq(expr, y.get(k, i));
      }
    }

    // delta definition constraints
    for (int k = 0; k < ins.getMaxClusterNumber(); ++k) {
      expr = solver.numExpr();
      for (int i = 0; i < ins.getNumNodes(); ++i) {
        expr = solver.sum(expr, y.get(k, i));
      }
      solver.addLe(solver.diff(expr, ins.getLambda()), d.get(k));
      solver.addGe(solver.diff(expr, ins.getLambda()), solver.prod(-1, d.get(k)));
    }

    // w var definition constraints
    for (int k = 0; k < ins.getMaxClusterNumber(); ++k) {
      for (OrderedPair p : fp) {
        expr = solver.numExpr();
        expr = solver.sum(expr, w.get(p.i, p.j));
        expr = solver.diff(expr, y.get(k, p.i));
        expr = solver.diff(expr, y.get(k, p.j));
        expr = solver.sum(expr, 1);
        solver.addGe(expr, 0);
      }
    }

    if (isActiveExtension(Extension.ROOT_MINIMIZATION_CONSTRAINTS)) {
      for (int k = 0; k < ins.getMaxClusterNumber(); ++k) {
        for (OrderedPair p : fp) {
          expr = solver.sum(y.get(k, p.i), r.get(k, p.j));
          solver.addLe(expr, 1);
        }
      }
    }

    if (isActiveExtension(Extension.POLYNOMIAL_ORBITOPE)) {
      // first family
      for (int k = 0; k < ins.getMaxClusterNumber(); ++k) {
        expr = solver.numExpr();
        for (int v = 0; v <= k - 1; ++v) {
          expr = solver.sum(expr, y.get(k, v));
        }
        solver.addEq(expr, 0);
      }
      // second family
      for (int k = 1; k < ins.getMaxClusterNumber(); ++k) {
        for (int v = k; v < ins.getNumNodes(); ++v) {
          expr = solver.numExpr();
          expr = solver.sum(expr, y.get(k, v));
          for (int u = k - 1; u <= v - 1; ++u) {
            expr = solver.diff(expr, y.get(k - 1, u));
          }
          solver.addLe(expr, 0);
        }
      }
    }

    if (isActiveExtension(Extension.EXPONENTIAL_ORBITOPE)) {
      System.err.println("Extension " + Extension.EXPONENTIAL_ORBITOPE + " not implemented yet");
      throw new IllegalArgumentException();
    }

    if (isActiveExtension(Extension.FLOW_LB)) {
      // f,x lower bound
      for (int k = 0; k < ins.getMaxClusterNumber(); ++k) {
        for (int i = 0; i < ins.getNumNodes(); ++i) {
          expr = solver.numExpr();
          for (Integer j : ins.getOutcut(i)) {
            expr = solver.sum(expr, f.get(k, j, i));
          }
          expr = solver.sum(expr, f.get(k, superRoot, i));
          solver.addGe(expr, y.get(k, i));
          solver.addLe(r.get(k, i), f.get(k, superRoot, i));
        }
      }
    }

    solver.setParam(IloCplex.DoubleParam.TiLim, timeout);
    if (isActiveExtension(Extension.ROOT_BRANCHING_PRIORITY)) {
      // Add branching priorities to the root variables
      for (int k = 0; k < ins.getMaxClusterNumber(); ++k)
        for (int i = 0; i < ins.getNumNodes(); ++i) solver.setPriority(r.get(k, i), 100);
    }
    solver.setParam(IloCplex.IntParam.ParallelMode, 1);
    solver.solve();
    System.out.println("STATE=" + solver.getStatus());
    System.out.println("NN=" + solver.getNnodes());
    System.out.println("LB=" + solver.getBestObjValue());

    // If we have a feasible solution we save it
    if (solver.getStatus() == IloCplex.Status.Feasible
        || solver.getStatus() == IloCplex.Status.Optimal) {
      for (int k = 0; k < ins.getMaxClusterNumber(); ++k) {
        for (int v = 0; v < ins.getNumNodes(); ++v) {
          if (FloatUtils.eq(solver.getValue(y.get(k, v)), 1.0)) {
            sol.insert(k, v);
          }
        }
      }
    }

    return solver.getObjValue();
  }
Ejemplo n.º 2
0
  public static void main(String[] args) {
    if (args.length < 1) {
      usage();
      return;
    }
    try {
      IloCplex cplex = new IloCplex();

      String fixedfile = null;
      String tunedfile = null;
      int tunemeasure = 0;
      boolean mset = false;
      Vector<String> filenames = new Vector<String>();

      for (int i = 0; i < args.length; ++i) {
        if (args[i].charAt(0) != '-') {
          filenames.add(args[i]);
          continue;
        }
        switch (args[i].charAt(1)) {
          case 'a':
            tunemeasure = 1;
            mset = true;
            break;
          case 'm':
            tunemeasure = 2;
            mset = true;
            break;
          case 'f':
            fixedfile = args[++i];
            break;
          case 'o':
            tunedfile = args[++i];
            break;
        }
      }

      System.out.println("Problem set:");
      for (String name : filenames) {
        System.out.println("  " + name);
      }

      if (mset) cplex.setParam(IloCplex.Param.Tune.Measure, tunemeasure);

      IloCplex.ParameterSet paramset = null;

      if (fixedfile != null) {
        cplex.readParam(fixedfile);
        paramset = cplex.getParameterSet();
        cplex.setDefaults();
      }

      int tunestat = cplex.tuneParam(filenames.toArray(new String[0]), paramset);

      if (tunestat == IloCplex.TuningStatus.Complete) System.out.println("Tuning complete.");
      else if (tunestat == IloCplex.TuningStatus.Abort) System.out.println("Tuning abort.");
      else if (tunestat == IloCplex.TuningStatus.TimeLim) System.out.println("Tuning time limit.");
      else System.out.println("Tuning status unknown.");

      if (tunedfile != null) {
        cplex.writeParam(tunedfile);
        System.out.println("Tuned parameters written to file '" + tunedfile + "'");
      }
      cplex.end();
    } catch (IloException e) {
      System.err.println("Concert exception caught: " + e);
    }
  }