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Questions tagged [cp-optimizer]

IBM ILOG CP Optimizer is a commercial constraint programming optimizer which is owned and sold by IBM.

IBM ILOG CP Optimizer is a commercial constraint programming optimizer which is owned and sold by IBM. It is included with IBM ILOG CPLEX Optimization Studio and is an alternative to traditional mathematical programming.

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CpoException: Can not execute command 'cpoptimizer -angel'. Please check availability of required executable file

I have CPLEX Optimization Studio installed on my Ubuntu machine and I am using the docplex model module with success. Now I have to use CpoModel from docplex.cp.model and I have the error: CpoException: Can not execute command 'cpoptimizer…
raisedbywolves
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How do I implement an If Then Expression to eventually use in a constraint in the ILOG CP Optimizer?

A brief description of the problem. I have a number of objects let's call this object X. Each X can be assigned to a number of containers Y. Each Y, needs two each of X. Each X has an attribute L. Each Y has a minimum specification of its L level,…
Realhermit
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Constraint Programming CP Optimizer - How to model a cumulative capacity constraint

I am new to the CP Optimizer (from ILOG), and am trying to find the right keywords to get me on a track to modelling cumulative capacity constraints. For example, I have two tasks: A, which lasts for 6 days and contributes 5 units per day to a…
Ryan Goodfellow
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How we can use a decision variable as an index of another decision variable using ILOG CP optimizer in python?

I am modeling a vehicle routing and scheduling problem using CP. I have 2 kinds of decision variables, that is, sequencing and start time of each node. The sequencing variable contains the node number, and start time of each node depends on the…
Saeede Hosseini
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How to save opl.postProcess(); output to an 2D array in Java

I'm using CP Optimizer from ILOG CPLEX Studio to run an optimization problem. Specifically, I'm running an OPL code in Java using Eclipse IDE. My code is working and I'm getting for an instance the following output: Where "Fitness" is the value of…
Fco.Jav.Y
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How does CP Optimizer compare to other constraint programming solvers/

In have recently addressed a couple of scheduling projects using CP Optimizer (the CPLEX Constraint Programming solver) and was able to get some really good results with it. However, compared to Cplex, CP Optimizer is still a big black box for me.…
wsg
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How to fix errors when using opl.end() in main flow control loop

I'm batch running tens of thousands of tests using a loop inside a main flow control block. Each run of the loop spawns a new OPL model using the designated .dat data file and .mod model file (which is separate from the batch runner .mod file which…
Jordan Ticktin
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How is the lower bound that is displayed created?

my Flexible Job Shop Problem (CP) shows me a result of Best objective :423 (gap is 49,88%) and Best bound: 212. So my question is how is this bound created? Because In my case the lowest value that can be theoretical achived is in the area…
Alex
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Is it possible to solve a CP formulated problem with the CPLEX-Engine without transforming the model?

I have formulated a flexible job shop problem as a CP model like it is advised in CPLEX Optimization Studio. The problem is running and creates correct schedules. So my question is if there is a possibilty also to let this problem be solved with the…
Alex
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How to define a sequence dependant constraint?

I want to model a constraint where I want to say if a mode mode1 is scheduled on a sequence before another mode mode2 then a mode mode3 on a parallel working machine (so in an other sequence) cannot be started before the end of mode1 in an other…
Alex
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How to code in a flexible job shop that the successor of an operation is done on the same machine?

In the model we have 3 operations that have to be performed for each Job. I would like that if operation 1 is processed in a machine of type OR, operation 2 and operation 3 also have to be performed on the same machine of type OR if they are…
Alex
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How to handle large integers in IBM ILOG CPLEX CP Optimizer?

This is a follow-up from this post. In short, I am using IBM ILOG CPLEX CP Optimizer in Python to solve a constraint programming problem. One of the optimization objectives is to maximize the product of integers x_1 * x_2 * ... * x_n. As the problem…
foo
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How I can make the restriction?

I'm new to the world cp optimizer and this starting to make small tests. I have the following question and I need your help, please. This is my code: Data const IloInt nbPair = 6; const IloInt nbPairElements = 15; const IloInt nbElement =…
Juan Carlos Pego
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Why is CPOptimizer unable to compute a lower bound for my model?

I am actually working on a problem recquiring to configure a manufacturing line by affecting machines to workstations, tasks to these workstations and select a configuration for every machine under the problem constraints (cadency, tasks'…
Loda
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Compile .so file from CPLEX C++ API and run using ctypes: undefined symbol error

I am trying to use ctypes (Python) to run an optimization model that was written in C++ with the CP Optimizer of CPLEX. I have successfully done this in MacOS, however, I am trying to do it in Linux and I am facing some errors that I cannot…
Paulo Nascimento
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