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Ryan Kersh

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RE: SIGSEGV when calling solve() in CPLEX

Posted By Ryan Kersh Wed June 03, 2020 06:22 PM
Found In Egroup: Decision Optimization \ view thread
This question was cross-posted on stackoverflow here. I left a comment there. ------------------------------ Ryan Kersh ------------------------------

RE: Getting the number of cuts added by CPLEX

Posted By Ryan Kersh Thu May 21, 2020 03:05 PM
Found In Egroup: Decision Optimization \ view thread
You can use the IloCplex.getNcuts function to get that information. For example: System.out.println("Gomory cuts: " + cplex.getNcuts(IloCplex.CutType.Frac));​ ------------------------------ Ryan Kersh ------------------------------

RE: Python CPLEX API: defining binary decision variables

Posted By Ryan Kersh Thu May 21, 2020 02:51 PM
Found In Egroup: Decision Optimization \ view thread
It sounds like you are looking for indicator constraints. Using the CPLEX Python API, you can create/modify/delete indicator constraints using the InidicatorConstraintInterface. See also the following examples that are included when you install CPLEX: fixnet.py foodmanu.py diet.py ...

RE: Freeing CPLEX takes too much time

Posted By Ryan Kersh Wed May 20, 2020 04:42 PM
Found In Egroup: Decision Optimization \ view thread
Hi Esra, Using the model you provided and CPLEX 12.7.1, I have not been able to reproduce the behavior you describe (nor with the most recent version, CPLEX 12.10). I used the following code (as suggested in one of the related threads I mentioned above): #include #include ILOSTLBEGIN ...

RE: CPLEX Out of Memory -> get last solution (Java)

Posted By Ryan Kersh Wed May 20, 2020 11:18 AM
Found In Egroup: Decision Optimization \ view thread
This question was cross-posted on stackoverflow here. It looks like you have accepted the answer there. In the future please pick one or the other (we watch both) so that we can avoid duplicate work among our team. ------------------------------ Ryan Kersh ------------------------------

RE: Freeing CPLEX takes too much time

Posted By Ryan Kersh Wed May 20, 2020 11:05 AM
Found In Egroup: Decision Optimization \ view thread
I received the model from Esra via email. I'll attempt to share it as a zip file here. EDIT: It looks like it worked. :-) ------------------------------ Ryan Kersh ------------------------------

RE: Freeing CPLEX takes too much time

Posted By Ryan Kersh Wed May 20, 2020 11:04 AM
Found In Library: Decision Optimization
#DecisionOptimization

RE: Freeing CPLEX takes too much time

Posted By Ryan Kersh Tue May 19, 2020 03:59 PM
Found In Egroup: Decision Optimization \ view thread
Did you forget the attachment? The CPLEX forum was recently moved here so I'm sorry in advance if it's attached and I just don't see it. I understand that you are stuck using Visual Studio 2013. However, in case you weren't aware of it, there is the free Visual Studio 2019 Community Edition available ...

RE: Freeing CPLEX takes too much time

Posted By Ryan Kersh Tue May 19, 2020 12:21 PM
Found In Egroup: Decision Optimization \ view thread
Have you have seen related posts in this forum like the following: env.end() takes long time Time to end model Is it possible for you to share one of your MIP instances in SAV format here? Is it possible for you to try using a more recent version of CPLEX (version 12.10 is currently available) ...

RE: getCplexStatus=3 when run via CPLEX Optimization Studio

Posted By Ryan Kersh Wed April 29, 2020 09:33 AM
Found In Egroup: Decision Optimization \ view thread
This is a new forum and I may be mistaken, but I don't see the LP file attachment. Did you forget to attach the LP file? From the log we can see that CPLEX thinks row 'c495' is infeasible. Did you take a close look at that? Did you happen to try turning presolve off? ------------------------------ ...

RE: How to use Indicator Constraint in Java API?

Posted By Ryan Kersh Tue April 28, 2020 04:02 PM
Found In Egroup: Decision Optimization \ view thread
I answered your question on stackoverflow here. ------------------------------ Ryan Kersh ------------------------------

Re: Numerical Emphasis Precision

Posted By Ryan Kersh Fri April 24, 2020 03:16 PM
Found In Egroup: Decision Optimization \ view thread
The numerical emphasis parameter is a BooleanParam in the Java API, so you must set it to either true or false. Replace: cplex.setParam(IloCplex.Param.Emphasis.Numerical, 0); With: cplex.setParam(IloCplex.Param.Emphasis.Numerical, true); That should do the trick. ...

Re: Barrier cannot determine infeasibility

Posted By Ryan Kersh Mon April 06, 2020 07:31 PM
Found In Egroup: Decision Optimization \ view thread
From the documentation for IloCplex, we have the following: The method IloCplex.getCplexStatus provides more detailed information about the status of the optimizer after IloCplex.solve returns. For example, it can provide information about why the optimizer terminated prematurely (time ...

Re: Different Result from Different environments

Posted By Ryan Kersh Fri March 27, 2020 09:34 AM
Found In Egroup: Decision Optimization \ view thread
Even small differences, like the order that the variables or constraints are created, or the precision of the coefficients, can give different results. There can also be many different optimal solutions. You didn't describe how the results are different; are we talking about different within tolerances ...

Re: CPXgetchgparam kind feature in java

Posted By Ryan Kersh Mon March 16, 2020 12:15 PM
Found In Egroup: Decision Optimization \ view thread
Hi John, I think I answered your question on this thread. In short, you should be able to do something like this: cplex.setParam(new IloCplex.BooleanParam(1132, "MyParamName"), true); #CPLEXOptimizers #DecisionOptimization

Re: There may be further error information in the clone logs.

Posted By Ryan Kersh Mon March 16, 2020 12:11 PM
Found In Egroup: Decision Optimization \ view thread
Hi John, Please try with the following constructor: cplex.setParam(new IloCplex.BooleanParam(1132, "MyParamName"), true); #DecisionOptimization #OPLusingCPLEXOptimizer

Re: CPXgetchgparam kind feature in java

Posted By Ryan Kersh Sat March 14, 2020 12:41 PM
Found In Egroup: Decision Optimization \ view thread
One way to do this is to simply write out the parameter file using IloCplex.writeParam(). Alternately, you can use IloCplex.getParameterSet(). For example: IloCplex.ParameterSet ps = cplex.getParameterSet(); for (java.util.Iterator it = ps.iterator(); it.hasNext();) ( ...

Re: Setting the coefficients of a two-dimensional variable in the objective function using Python API

Posted By Ryan Kersh Tue March 10, 2020 02:28 PM
Found In Egroup: Decision Optimization \ view thread
The CPLEX Python API is a lightweight wrapper around the CPLEX C Callable Library. There is no concept of two-dimensional variables at this level. So, you'll have to maintain the mapping yourself from two dimensions to one. This can be done in various ways, but Cplex.variables.add() returns an iterator ...

Re: Setting the coefficients of a two-dimensional variable in the objective function using Python API

Posted By Ryan Kersh Mon March 09, 2020 07:24 PM
Found In Egroup: Decision Optimization \ view thread
The obj argument should be a one-dimensional list (similar to the way you are setting the types argument). For example: obj=[0.0] * (K * I) If you installed CPLEX in the standard way, then you should check out the python examples that are shipped with CPLEX (e.g., lpex1.py, mipex1.py, ...

Re: java.lang.UnsatisfiedLinkError

Posted By Ryan Kersh Wed February 05, 2020 03:18 PM
Found In Egroup: Decision Optimization \ view thread
As the error says, you'll need to set java.library.path to the directory where the cplex1280.dylib shared library is located. When you install CPLEX Optimization Studio there are examples and a Makefile that will show you exactly what you need to use on the command line. You can run the examples, ...