I have a C API program uploaded here in Dropbox that is an LP. Here is the problem: When I compile the C file it gives me "1017 Not available for mixed-integer problems" while the problem is apparently LP. At the same time, when it prints its solution, it is integer. However, when I write the lp in a .lp file and solve it with CPLEX terminal, it gives the right solution.

  • $\begingroup$ Can you identify which line in the C file generates the 1017 error? $\endgroup$
    – prubin
    Dec 19, 2022 at 17:13
  • $\begingroup$ @prubin: This is a small block of a larger callback program. BTW, this is so strange, I never faced something like this. Even in my larger code, I am not able to solve this part as a linear programming. The interesting part is when I change type of variables to integer and use mipopt instead of lpopt. No error at all. $\endgroup$
    – Max
    Dec 19, 2022 at 18:04
  • $\begingroup$ Presumably, you don't have my error! line 2302. $\endgroup$
    – Max
    Dec 19, 2022 at 20:28
  • 1
    $\begingroup$ I don't use C, so I can't run your code. Line 2302 is a print statement, so that's an unlikely location for the error to occur. $\endgroup$
    – prubin
    Dec 19, 2022 at 21:18
  • $\begingroup$ I can provide my makefile if it works for you. Definitely, the error refers to line 2295 (CPXlpopt). Here is the point: even CPXgetprobtype returns MILP, while there is no integer/binary variable in the problem. $\endgroup$
    – Max
    Dec 19, 2022 at 21:26


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