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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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How to print constraint evaluation in OPL for a specific instance

I have a simple question but I can't find how to tackle it. For instance, consider the following .mod file from a scheduling problem in OPL using the CP Optimizer solver. using CP; int nbJobs = ...; int nbMchs = ...; range Jobs…
Fco.Jav.Y
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CP Optimizer CPLEX - Multiple optimal solutions

I am currently using the Python API of the CP Optimizer of CPLEX to obtain the optimal solution of a scheduling problem. Depending on the instance, there might be multiple equivalent optimal solutions. I would assume that during the searching…
Paulo Nascimento
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How can I add objective for scheduling model to count the present decision variables to be specific value using CPlex Python?

I am working on the scheduling problem where I want to add an objective according to such condition. So is there any way to count the present interval variables (like presence_of()) to apply some condition for an objective? Thanks in advance!
Gops
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CpoException: Executable file should be given in 'execfile' context attribute

the line in question that is giving me problems is the following: msol = mdl.solve(TimeLimit=20, trace_log=False, execfile='\Applications\CPLEX_Studio_Community201\cpoptimizer\bin\x86-64_osx\cpoptimizer.exe') Producing the following…
Manuel Lopez
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docplex - set an interval_var's size as a function of another variable

In IBM's docplex optimization library, can you set an interval_var's size parameter as a function of another variable? Meaning, say for this example I wanted to make the task size dependent on the skill level of the worker. If the worker has a skill…
conv3d
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unexpected cumulFunction evaluation with CPLEX (CP Optimizer)

I get the objective value h=3 with the following CPLEX code: using CP; dvar interval lot1 in 10..19; dvar interval lot2 in 20..29; cumulFunction cumulFunc1 = stepAtStart(lot1, 1); cumulFunction cumulFunc2 = stepAtStart(lot2, 2); cumulFunction func…
shira
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How to give to CP Optimizer an initial feasible solution

I need to solve a hard scheduling problem. For that purpose, I get an initial feasible solution using a greedy heuristic. This heuristic gives me the starting time of every job in every machine. How can I initialize CP Optimizer with this initial…
Fco.Jav.Y
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How to stop the search in CP Optimizer if the upper bound doesn't get better after x seconds

I'm wondering if there exists a way in CP Optimizer 12.10 to stop the search if the upper bound (of a minimization problem) doesn't get better after "x" seconds. This would be especially helpful when trying to solve a difficult instance of an…
Fco.Jav.Y
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What are Global Constraints in constraint programming?

I see that ORTools and CpOptimizer both use global constraints. I know it speeds up the search a lot, but what does it actually do? Like what is the difference between me using (1) or (2) below; Example for the AllDifferent constraint: 1) x1 != x2,…
Flemming Juel Jensen
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How to adapt and OPL code to Java API using Eclipse IDE

I am trying to adapt an OPL formulation using the Java API in Eclipse IDE. Extraction of the original OPL code is the following: using CP; int nbJobs = ...; int nbMchs = ...; range Jobs = 0..nbJobs-1; …
Fco.Jav.Y
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How to export every feasible solution from IBM ILOG CPLEX?

Currently I am working on a scheduling problem using IBM ILOG CPLEX using its OPL. I can only export the optimal solution using sheetWrite command but I would like to export the results of each feasible solution not only the optimal solution. Could…
Mohamed Menessy
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CPLEX using if then constraints with CP optimizer in C#

Please help me if anyone can solve this problem, and I would be so appreciated. If there is a vehicle which can transport the material from machine 1 to machine 2 or from machine 4 to machine 3, which means there are two optional intervals (named…
Yuan
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CPLEX-OPL: New bound is 0 and no result when adding a new constraint

I tried to run a MILP (OPL) on CPLEX 12.8.0. After add this constaint to the model and run, engine log as showed and get no other reuslt. how do i fix this problem ? Thank you. EQ11 : // 1TruckPourAtSameCustomer&Time; forall(c in customer, m in…
Natdanai I.
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How to model capacity constraints with pick-up and delivery operations with CP Optimizer?

I am modeling a scheduling problem with capacity constraints. The task is to schedule a set of operations that have to be carried out by a specific machinez. More especifically, I have a set of vehicles and a set of locations, and the vehicles have…
David Sacramento
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Is there an example that uses the flexible job shop problem with CPLEX instead of CP?

I´m a beginner in CPLEX and I want to ask if there is any example available that modifies the flexible job shop example in a way that it can be solved with CPLEX and not with CP?
Alex
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