/* * (non-Javadoc) * * @see net.sf.javailp.Solver#solve(net.sf.javailp.Problem) */ public Result solve(Problem problem) { Map<IloNumVar, Object> numToVar = new HashMap<IloNumVar, Object>(); Map<Object, IloNumVar> varToNum = new HashMap<Object, IloNumVar>(); try { IloCplex cplex = new IloCplex(); initWithParameters(cplex); for (Object variable : problem.getVariables()) { VarType varType = problem.getVarType(variable); Number lowerBound = problem.getVarLowerBound(variable); Number upperBound = problem.getVarUpperBound(variable); double lb = (lowerBound != null ? lowerBound.doubleValue() : Double.NEGATIVE_INFINITY); double ub = (upperBound != null ? upperBound.doubleValue() : Double.POSITIVE_INFINITY); final IloNumVarType type; switch (varType) { case BOOL: type = IloNumVarType.Bool; break; case INT: type = IloNumVarType.Int; break; default: // REAL type = IloNumVarType.Float; break; } IloNumVar num = cplex.numVar(lb, ub, type); numToVar.put(num, variable); varToNum.put(variable, num); } for (Constraint constraint : problem.getConstraints()) { IloLinearNumExpr lin = cplex.linearNumExpr(); Linear linear = constraint.getLhs(); convert(linear, lin, varToNum); double rhs = constraint.getRhs().doubleValue(); switch (constraint.getOperator()) { case LE: cplex.addLe(lin, rhs); break; case GE: cplex.addGe(lin, rhs); break; default: // EQ cplex.addEq(lin, rhs); } } if (problem.getObjective() != null) { IloLinearNumExpr lin = cplex.linearNumExpr(); Linear objective = problem.getObjective(); convert(objective, lin, varToNum); if (problem.getOptType() == OptType.MIN) { cplex.addMinimize(lin); } else { cplex.addMaximize(lin); } } for (Hook hook : hooks) { hook.call(cplex, varToNum); } if (!cplex.solve()) { cplex.end(); return null; } final Result result; if (problem.getObjective() != null) { Linear objective = problem.getObjective(); result = new ResultImpl(objective); } else { result = new ResultImpl(); } for (Entry<Object, IloNumVar> entry : varToNum.entrySet()) { Object variable = entry.getKey(); IloNumVar num = entry.getValue(); VarType varType = problem.getVarType(variable); double value = cplex.getValue(num); if (varType.isInt()) { int v = (int) Math.round(value); result.putPrimalValue(variable, v); } else { result.putPrimalValue(variable, value); } } cplex.end(); return result; } catch (IloException e) { e.printStackTrace(); } return null; }