Originally posted by: MLJ

When solving problems with Cplex through the AMPL interface, I obtain the error message below. Could somebody explain me what it is due to and how to resolve this? Note that, for some problems, the optimization finishes without any issue.

IBM ILOG AMPL 12.1.0 (5724-Y45) AMPL Version (x64_win64)
ampl: include PortALL3.run;
CPLEX 12.1.0: Error at _cmdno 2 executing "solve" command
(file PortALL3.run, line 19, offset 524):
can't open at2076.sol

Thank you.
#CPLEXOptimizers
#DecisionOptimization

Originally posted by: SystemAdmin

The error message is singularly unhelpful; CPLEX passes its solution back to AMPL through the blahblah.sol file, and the message just says that CPLEX never wrote the file. So something (as yet unspecified) went wrong.

Unless you made a parameter setting to eliminate the log, the usual output from CPLEX should have appeared in AMPL's console output. Is there anything there that tips off why CPLEX failed to generate the solution file?

/Paul

Mathematicians are like Frenchmen: whenever you say something to them, they translate it into their own language, and at once it is something entirely different. (Goethe)
#CPLEXOptimizers
#DecisionOptimization

Originally posted by: SystemAdmin

Not sure but it looks to me that in line 19 of file PortALL3.run you attempt to access a file called at2076.sol and that file could not be found.
May this be the cause of your problems? Not an ampl expert, sorry.
#CPLEXOptimizers
#DecisionOptimization

Originally posted by: SystemAdmin

The AMPL/CPLEX interface code is supposed to write the solution found by CPLEX to the .sol file (or, I assume, the reason why there is no solution, such as infeasibility). So, barring a misadventure with operating system causing it to prevent a file write, the message probably means that something bad happened with CPLEX.

I see the question has migrated to the AMPL forum, but I think it comes down to diagnosing what happens when CPLEX tries to solve the model.

/Paul

Mathematicians are like Frenchmen: whenever you say something to them, they translate it into their own language, and at once it is something entirely different. (Goethe)
#CPLEXOptimizers
#DecisionOptimization