All Questions
18 questions
0
votes
0
answers
177
views
Indication warm start infeasible in CPLEX
I'm running LP problem in CPLEX with JAVA API. I'm trying to model a greedy solution by fixing a maximal number of variables until I get a feasible solution.
I use this to fix the variables:
cplex....
user7738429
0
votes
1
answer
380
views
How to clone a cplex object in Java?
I am solving a problem in Java using the CPLEX library. I use a class "Model" to create a CPLEX object, and add to it variables, objective function and multiple constraints. This is the ...
0
votes
1
answer
280
views
Output a two-dimensonal variable array in cplex
Currently I am trying to output a two dimensonal array of variables in CPLEX. The array is defined in the following way:
IloNumVar[][] y = new IloNumVar[numJobs][];
for(int j=0; j<numJobs; j++){
...
- 3
1
vote
1
answer
601
views
Multiple Objective Optimization Java
I've implemented a linear programming problem using the CPLEX API in Java. This problem has 5 linear objectives with different scales. I've tried to implement some normalization methods, but without ...
- 695
0
votes
1
answer
384
views
Get all extreme points of Linear Program in CPLEX
I need to enumerate all basis corresponding to all extreme points of a LP with the CPLEX API in Java. Unfortunately I did not find any way to do this with CPLEX. Is there a solution ?
If not, I will ...
- 377
0
votes
0
answers
149
views
Conflict Refiner Preferences Cplex
As far as I understood, in ConflictRefiner of CPLEX, the preference array should guide the method to find the conflict Set that is more desirable. But in the code below, no matter how do I modify the ...
- 1
0
votes
1
answer
339
views
Java Cplex Reduced Optimality and First Feasible Solution
I am working on a LP written in Java and using cplex as a solver. The optimal solution takes some time to be found. It would be sufficient if I had a feasible solution that would be calculated faster ...
- 1,057
1
vote
0
answers
97
views
How to access dual value of a constraint implied by dvar bounds?
Given a simple (nonsense) linear program:
Minimize
obj: x1 + x2 + x3
Subject To
CT1: x1 + x2 + x3 = 5
Bounds
1 <= x1 <= 100
0 <= x2 <= 100
0 <= x3 <= 100
I use the Java Cplex ...
1
vote
1
answer
2k
views
Java Cplex Expressions and Constraints
I am trying to understand what exactly Expressions in cplex are and how I can use them in Java for creating a Linear Programm. Unfortunately there aren't any sufficient examples in the documentation ...
- 1,057
0
votes
0
answers
437
views
CPLEX float precision
Question: How small can a float be before CPLEX sees it as 0?
I am asking this question because my ILP usually deals with small numbers however now it has encountered numbers of 10^-18 to 10^-35. And ...
- 172
0
votes
1
answer
459
views
Printing CPLEX eliminated rows, columns and substitutions
I am using Java API of CPLEX optimization software. After the solver finishes the optimization, it prints the solution and the parameters of the LP as well:
MIP Presolve eliminated 282 rows and 230 ...
- 455
1
vote
2
answers
2k
views
Goal Programming in Cplex
Let's say I have the two goals. I want to reach that goals really close:
i=1) profit goal: 12𝑥 + 9y ≥ 125
i=2) cost-goal: 5𝑥 + 7y ≤ 50
In the literature you can do goal-programming by inserting ...
- 315
1
vote
1
answer
647
views
setting bounds for a constraint in CPLEX Concert Technology Java
I am defining a constraint in a class and later I am calling that class. Now I want to define range for the constraint created. How to set upper bound for the constraint. Relevant part of the code ...
- 49
0
votes
1
answer
371
views
Cplex Term with 2 variables
i want to add this constraint to my ILP in cplex using java.
u_jk >= (u_ik + d_i + t_ij)x_ijk
IloLinearNumExpr right = cplex.linearNumExpr();
right.addTerm(serviceDuration , x[i][j][k]);
...
0
votes
1
answer
391
views
creating two kinds of dependent variable using cplex and java
I am new to work by CPLEX. My simplified optimization problem is:
objective function:
Maximize z1 + z2 + z3
Subject to:
c1: x1 - 3 x2 + x3 <= 30
c2: x1 + ...
- 69