Qp.java
/ * 2021年版权,Gurobi优狗万app足彩化,LLC * / / *本例制定和解决以下简单的QP模型:最小化x ^ 2 + x * y + y ^ 2 + y * z + z ^ 2 + 2 x, x + 2 + 3 z > = 4 x + y > = 1 x, y, z非负它解决它曾经作为一个连续的模式,一旦为整数模型。* /进口gurobi。*;public class Qp {public static void main(String[] args) {try {GRBEnv env = new GRBEnv(" Qp .log");= new GRBModel(env);//创建变量GRBVar x = model.addVar(0.0, 1.0, 0.0, GRB.);连续的," x ");y = model.addVar(0.0, 1.0, 0.0, GRB。连续的," y ");GRBVar z = model.addVar(0.0, 1.0, 0.0, GRB。连续的,“z”);//设置obj = new GRBQuadExpr();obj.addTerm (1.0 x, x);obj.addTerm (1.0, x, y); obj.addTerm(1.0, y, y); obj.addTerm(1.0, y, z); obj.addTerm(1.0, z, z); obj.addTerm(2.0, x); model.setObjective(obj); // Add constraint: x + 2 y + 3 z >= 4 GRBLinExpr expr = new GRBLinExpr(); expr.addTerm(1.0, x); expr.addTerm(2.0, y); expr.addTerm(3.0, z); model.addConstr(expr, GRB.GREATER_EQUAL, 4.0, "c0"); // Add constraint: x + y >= 1 expr = new GRBLinExpr(); expr.addTerm(1.0, x); expr.addTerm(1.0, y); model.addConstr(expr, GRB.GREATER_EQUAL, 1.0, "c1"); // Optimize model model.optimize(); System.out.println(x.get(GRB.StringAttr.VarName) + " " +x.get(GRB.DoubleAttr.X)); System.out.println(y.get(GRB.StringAttr.VarName) + " " +y.get(GRB.DoubleAttr.X)); System.out.println(z.get(GRB.StringAttr.VarName) + " " +z.get(GRB.DoubleAttr.X)); System.out.println("Obj: " + model.get(GRB.DoubleAttr.ObjVal) + " " + obj.getValue()); System.out.println(); // Change variable types to integer x.set(GRB.CharAttr.VType, GRB.INTEGER); y.set(GRB.CharAttr.VType, GRB.INTEGER); z.set(GRB.CharAttr.VType, GRB.INTEGER); // Optimize again model.optimize(); System.out.println(x.get(GRB.StringAttr.VarName) + " " +x.get(GRB.DoubleAttr.X)); System.out.println(y.get(GRB.StringAttr.VarName) + " " +y.get(GRB.DoubleAttr.X)); System.out.println(z.get(GRB.StringAttr.VarName) + " " +z.get(GRB.DoubleAttr.X)); System.out.println("Obj: " + model.get(GRB.DoubleAttr.ObjVal) + " " + obj.getValue()); // Dispose of model and environment model.dispose(); env.dispose(); } catch (GRBException e) { System.out.println("Error code: " + e.getErrorCode() + ". " + e.getMessage()); } } }
