Hi,
I tried to run my model but always got an infeasible solution. I searched on the forum about that error and found that I need to use option IIS to debug my model. Also, I checked every single post and CPLEX option to know how to conduct this option, but I couldn't know how to use that option in my model.
Would someone help me with this issue?
I appreciate any help you can provide.
CPLEX Error 1217 Topic is solved
Re: CPLEX Error 1217
You can ignore the error 1217. The GAMS link makes a call to Cplex to retrieve (the infeasible) "solution" and that fails, because the infeasibility was detected during presolve. Even without the iis the log gives you good information:
The iis gives you:
That should allow you to find the infeasibility.
-Michael
Code: Select all
Row 'C3(r1)' infeasible, all entries at implied bounds.
Code: Select all
Number of equations in conflict: 3
lower: C3(r1) > 2.1
upper: C5(x1,r1) < 0
upper: C6(r1,t1) < 0.4
Number of variables in conflict: 3
lower: x(x3,r1) > 0
lower: x(x4,r1) > 0
lower: x(x5,r1) > 0
-Michael
Re: CPLEX Error 1217
Hi,
Thanks a lot for your quick reply.
Also, I would like to know how did you use the IIS option or how to use any option in CPLEX?
I checked the available solver manual, but i could understand how to use the option in my code.
Thanks in advance
Thanks a lot for your quick reply.
Also, I would like to know how did you use the IIS option or how to use any option in CPLEX?
I checked the available solver manual, but i could understand how to use the option in my code.
Thanks in advance
Re: CPLEX Error 1217
It is well documented in gams solver usage.
https://www.gams.com/latest/docs/UG_Sol ... PTION_FILE
copy the following lines of code anywhere in your gams file.
This will create the options file. You can then tell the solver to look for option file by writing the following statement before solve.
<modelname>.optfile=1;
where <modelname> is your modelname. So if your model name is x, you should have x.optfile=1;
- Atharv
https://www.gams.com/latest/docs/UG_Sol ... PTION_FILE
copy the following lines of code anywhere in your gams file.
Code: Select all
$onecho > cplex.opt
iis 1
$offecho
<modelname>.optfile=1;
where <modelname> is your modelname. So if your model name is x, you should have x.optfile=1;
- Atharv