Stack Overflow
Stack Overflow

Questions tagged [cplex]

CPLEX is a fast commercial linear, quadratic, and mixed-integer optimizer. CPLEX offers a number of pre and post-processing tools allowing the software to substantially reduce the number of variables (columns) and constraints (rows) of a model. It is possible to solve models via an interactive shell, OPL (Optimization Programming Language), or a number of interfaces to programming languages, such as C, C++, Java, C#, Python, and MATLAB.

CPLEX is a commercial mathematical optimizer now owned and sold by IBM. It can solve continuous and mixed-integer optimization problems with linear and convex quadratic constraints and objectives and second-order cone problems. The core solver is written in C, but APIs are available for C, C++, Java, C#, Python, and MATLAB.

User's guide and API reference is available in the following formats:

  • PDF (for V12.1)
  • HTML (for V12.3 and up)

For troubleshooting questions that may involve back-and-forth (including posting attachments), or technical discussions about the algorithms, consider posting your question on the official IBM developerWorks forum instead.

1757 questions
51
votes
13 answers

Best open source Mixed Integer Optimization Solver

I am using CPLEX for solving huge optimization models (more than 100k variables) now I'd like to see if I can find an open source alternative, I solve mixed integer problems (MILP) and CPLEX works great but it is very expensive if we want to scale…
Mark
  • 9,893
  • 18
  • 55
  • 80
15
votes
7 answers

mathematical optimization library for Java --- free or open source recommendations?

Does anyone know of such a library that performs mathematical optimization (linear programming, convex optimization, or more general types of problems)? I'm looking for something like MATLAB, but with the ability to handle larger problems. Do I have…
Zach Scrivena
  • 27,585
  • 10
  • 60
  • 72
12
votes
2 answers

Solving an integer linear program: why are solvers claiming a solvable instance is infeasible?

I'm trying to solve integer programming problems. I've tried both use SCIP and LPSolve For example, given the final values of A and B, I want to solve for valA in the following C# code: Int32 a = 0, b = 0; a = a*-6 + b + 0x74FA - valA; b = b/3 + a +…
Craig Gidney
  • 16,378
  • 4
  • 62
  • 124
11
votes
1 answer

How to make cplex not output to terminal

I am using the IBM cplex optimizer to solve an optimization problem and I don't want all terminal prints that the optimizer does. Is there a member that turns this off in the IloCplex or IloModel class? These are the prints about cuts and…
DiegoNolan
  • 3,631
  • 1
  • 19
  • 26
9
votes
1 answer

How Can an Elastic SubProblem in PuLP be used as a Constraint?

In Python PuLP, a linear programming constraint can be turned into an elastic subproblem. http://www.coin-or.org/PuLP/pulp.html?highlight=lpsum#elastic-constraints Solving the subproblem optimizes the distance from the target value. Of course, the…
Bret Fontecchio
  • 619
  • 5
  • 16
8
votes
1 answer

How to disable the output messages in CPLEX solver?

I am using Pulp modeler with python to solve an integer programming problem. I am using IBM CPLEX as a solver. When I run my Python program, I have a lot of output messages in the console like: The CPLEX Optimizers will solve problems up to 1000…
Learning
  • 183
  • 6
6
votes
2 answers

Interpretation of GAP in CPLEX

This is a part of the engine-log output that I get from a small-scale mixed integer linear optimization problem that I solved in CPLEX 12.7.0 Nodes Cuts/ Node Left Objective IInf Best Integer …
Riegsche
  • 81
  • 1
  • 5
6
votes
2 answers

Is a library (with C programming language interface) callable from within ABAP?

I have no experience with ABAP programming and I'd like to know whether it's possible to call a 3rd party library with C programming language interface from within an SAP application. To be more precise, the goal is to use the IBM CPLEX Optimizer…
llasarov
  • 1,937
  • 5
  • 22
  • 37
6
votes
1 answer

Speed of CPLEX vs CPLEX using SCIP

I am new to LP and have only briefly used PuLP in Python. Why is there a speed difference between SCIP 3.2.1 - CPLEX 12.63 and CPLEX 12.6.3? Doesn't SCIP still use CPLEX for solving? Why will someone use SCIP with CPLEX solver, instead of using…
Nyxynyx
  • 52,075
  • 130
  • 401
  • 707
6
votes
2 answers

Representing Travelling Salesman as Linear Expression

I've seen online that one can write the travelling salesman problem as a linear expression and compute it using software such as CPLEX for java. I have a 1000 towns and need to find a short distance. I plan on partitioning these 1000 towns into…
Greg Peckory
  • 6,660
  • 15
  • 61
  • 101
5
votes
2 answers

IBM Watson CPLEX Shows no Variables, no Solution when solving LP file

I'm migrating an application that formerly ran on IBM's DoCloud to their new API based off of Watson. Since our application doesn't have data formatted in CSV nor a separation between the model and data layers it seemed simpler to upload an LP file…
Michoel
  • 784
  • 4
  • 16
5
votes
1 answer

Docplex vs CPLEX Python API

What is the difference between Docplex and CPLEX Python API? Is any of them faster than the other?
Snochacz
  • 555
  • 1
  • 4
  • 17
5
votes
1 answer

Fast nonnegative quantile and Huber regression in R

I am looking for a fast way to do nonnegative quantile and Huber regression in R (i.e. with the constraint that all coefficients are >0). I tried using the CVXR package for quantile & Huber regression and the quantreg package for quantile…
Tom Wenseleers
  • 6,574
  • 5
  • 46
  • 98
5
votes
2 answers

error: iostream.h due to including cplex

I am trying to use cplex in eclipse in Ubuntu 12.04 but when I include ilocplex.h I get the following error /opt/ibm/ILOG/CPLEX_Studio124/concert/include/ilconcert/ilosys.h:360:22: fatal error: iostream.h: No such file or directory The only two…
Shahab
  • 109
  • 2
  • 8
5
votes
3 answers

Cplex Python how to avoid printing the output

after setting the objective function and constraints, i use prob.solve() print prob.solution.get_objective_value() actually, I just want to print the objective value, however, it displays a lot of information of cplex, Tried aggregator 1 time. LP…
ilovecp3
  • 2,325
  • 4
  • 15
  • 19
1
2 3
…
99 100