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Mohamed Awad

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1 to 20 of 38 total

How to know the constraint propagation, backtracking, and branching techniques in OPL model?

Posted By Mohamed Awad Sat September 09, 2023 12:47 PM
Found In Egroup: Decision Optimization \ view thread
Hi, I would like to know how to know the constraint propagation, backtracking, and branching technique used in OPL model. Is there a way to control these settings for example. Best regards, Mohamed ------------------------------ Mohamed Awad ----------------------- ...

How to keep the model solving for certain number of iterations?

Posted By Mohamed Awad Fri June 09, 2023 04:45 PM
Found In Egroup: Decision Optimization \ view thread
Hi, I am running a CP model for certain number of iterations. For each iteration, a set of initial data is randomly generated. I am using control flow to run the iterations. As I using epsilon-constraint method in the multi-objective problem I am solving, I have to specify one of the objective functions ...

RE: How to use Java function in OPL Model?

Posted By Mohamed Awad Sat April 22, 2023 02:38 PM
Found In Egroup: Decision Optimization \ view thread
Hi Alex, Thank you for you reply. It will help to achieve what I am looking for. I have a question on: var rnd = IloOplCallJava("java.util.Random", " ", "()"); How can I use IloOplCallJava to generate random integer number between upper and lower limits. I tried the following but it didn't ...

How to use Java function in OPL Model?

Posted By Mohamed Awad Sat April 08, 2023 10:03 AM
Found In Egroup: Decision Optimization \ view thread
Hi, I have a question that I am struggling to get the answer for. I would like to read data from external excel file using the following code. execute ( var excelFile = "path/to/excel/file.xlsx"; var dataSource = new IloOplExcelDataSource(excelFile); dataSource.addTable("ProcessingTimes", ...

How to use Java function in OPL Model?

Posted By Mohamed Awad Tue February 21, 2023 12:53 PM
Found In Egroup: Decision Optimization \ view thread
Hi, I would like to use the following script to read from external excel file: execute ( var excelFile = "path/to/excel/file.xlsx"; var dataSource = new IloOplExcelDataSource(excelFile); dataSource.addTable("ProcessingTimes", "A1:D100"); thisOplModel.addDataSource(dataSource); ...

RE: How to declare conditional-optional dvar in CP?

Posted By Mohamed Awad Wed November 23, 2022 02:20 PM
Found In Egroup: Decision Optimization \ view thread
Hi Alex, Thanks a million. That's close to what I am looking for. Best regards, Mohamed ------------------------------ Mohamed Awad ------------------------------

RE: How to declare conditional-optional dvar in CP?

Posted By Mohamed Awad Wed November 23, 2022 12:58 PM
Found In Egroup: Decision Optimization \ view thread
Hi Alex, Thank you for you reply. In the code you sent, there were 5 itvs intervals, 3 of them were absent however, they were declared and no values were assigned to them. This will consume memory even if no values were assigned to the absent decision intervals. Is there a way to make the results ...

RE: How to declare conditional-optional dvar in CP?

Posted By Mohamed Awad Wed November 23, 2022 12:53 PM
Found In Egroup: Decision Optimization \ view thread
Hi Olivier, Thank you for you reply. I sent a small part of the OPL model I am working on. That's why it wasn't clear. The decision variable activity is declared over two arrays; allActivities_tri & allActivities_2. I am looking for something like: dvar interval activity[a in allActivities_tri][b ...

How to declare conditional-optional dvar in CP?

Posted By Mohamed Awad Tue November 22, 2022 03:52 PM
Found In Egroup: Decision Optimization \ view thread
Hi, I have a question on how to declare a conditional-optional decision variable in CP. I have a decision variable (i.e., activity) which is declared over two tuples (i.e., allActivities_tri & allActivities_2). These tuples are as follow: tuple ActivityInfo ( key string activity; string activity_type; ...

RE: Error on docplex.cp.model/CpoBlackboxFunction

Posted By Mohamed Awad Tue October 11, 2022 02:29 PM
Found In Egroup: Decision Optimization \ view thread
Dear Renaud, Thank you for your feedback. I ran the example you attached and it worked perfectly. Please find below the example output for your information. ! ---------------------------------------------------------------------------- ! Search terminated by limit, 69 solutions found. ! Best ...

Error on docplex.cp.model/CpoBlackboxFunction

Posted By Mohamed Awad Mon October 03, 2022 11:27 AM
Found In Egroup: Decision Optimization \ view thread
Hi, I have a problem whenever I run scheduling job-shop problem (sched_jobshop_blackbox.py) using blackbox function (CpoBlackboxFunction) from Python. When I run it on Python 3.7 using pyCharm, after installing CPLEX Studio 22.1, I receive the following error: C:\Users\MA\Anaconda3\envs\pytho ...

Can't download ILOG CPLEX using academic initiative

Posted By Mohamed Awad Tue August 02, 2022 04:46 PM
Found In Egroup: Decision Optimization \ view thread
Dears, I would appreciate if you can help me with the following error which is preventing me from downloading ILOG CPLEX using academic initiative: Or could you please send me a direct link to download CPLEX Optimization Studio 22.1 for Windows. Thanks in advance, Mohamed ------------ ...

RE: Is Constraint-programming (CP) solver derivative-free?

Posted By Mohamed Awad Fri April 22, 2022 01:17 PM
Found In Egroup: Decision Optimization \ view thread
Hi Renaud, Thank you for your kind feedback. Really appreciated. Best regards, ------------------------------ Mohamed Awad ------------------------------

RE: How to run multiple instances of the same model in parallel?

Posted By Mohamed Awad Fri April 22, 2022 01:16 PM
Found In Egroup: Decision Optimization \ view thread
Dear Renaud, Thank you for your kind reply. I would appreciate if you could help with more resources on how to perform a shell script for this case. Thanks in advance, ------------------------------ Mohamed Awad ------------------------------

How to run multiple instances of the same model in parallel?

Posted By Mohamed Awad Fri April 22, 2022 10:56 AM
Found In Egroup: Decision Optimization \ view thread
Dears, I have a question on parallel processing using OPL. I have a model which consumes time to be solved. I need to run the model for multiple scenarios however, if I do this in series, it will take very long time to get the results. How can I run the same model for multiple scenarios in parallel ...

Is Constraint-programming (CP) solver derivative-free?

Posted By Mohamed Awad Fri April 22, 2022 10:50 AM
Found In Egroup: Decision Optimization \ view thread
Dears, I have a question regarding CP solver. What is the difference between CP and Constrained Derivative-Free Optimization (CDFO). Are they the same. Is Constraint-programming (CP) solver a derivative-free optimisation method? Thanks in advance, ------------------------------ Mohamed Awad ...

RE: Set Seeds with Flow Control- OPL

Posted By Mohamed Awad Tue March 01, 2022 10:52 AM
Found In Egroup: Decision Optimization \ view thread
Hi Alex, Thanks a million for your great help. I really appreciate the time you always spend in replying for questions. Maybe I couldn't understand your solution. In my problem, I need to run the model 5 times via the flow control model (Question_Flow.mod) which also exports the results of each ...

Set Seeds with Flow Control- OPL

Posted By Mohamed Awad Mon February 28, 2022 05:02 AM
Found In Egroup: Decision Optimization \ view thread
Dears, I have a question on how to set seeds for random numbers generation. I am using OPL for a scheduling problem which requires generating random numbers. For clarity, I simplified my problem and attached all the necessary files. I was able to generate these random numbers using the pre-processing ...

Set Seeds with Flow Control- OPL

Posted By Mohamed Awad Mon February 28, 2022 05:01 AM
Found In Library: Decision Optimization
#DecisionOptimization

RE: Question of optimality gap of CP solver

Posted By Mohamed Awad Mon February 28, 2022 04:51 AM
Found In Egroup: Decision Optimization \ view thread
Thanks a million Paul for your great help. Really appreciated! Waiting for IBM experts to advise on how the lower bound is calculated for CP models. Best regards, Mohamed ------------------------------ Mohamed Awad ------------------------------