Hi all, I used glpsol to solve the linear relaxed version of a MIP problem ( all variables in my problem are 0 or 1) and output the solution using -o flag. What I want is to get all those variables which have been set to either 0 or 1 as a part of the solution and do not have a fractional value. In the output file , I extracted all the column ids having value 0 or 1 and added these as a new set of constraints to the original MIP problem by fixing the variables as 0 or 1 according to the relaxed solution.
Thus, this new MIP problem should surely be feasible right? I did that but I found the new MIP problem to be infeasible. I dont know why this is happening. The problem instance is present at http://www.cse.ohio-state.edu/~khannag/bip_8_20_new.lp. The solution I get when I run the relaxed version of the problem is present at http://www.cse.ohio-state.edu/~khannag/solution In this solution file, I took the value for column name under the activity label as their solution value. Based on my interpretation of the output file, 9409 variables out of 10244 were either 0 or 1 according to the number under the Activity Label in the solution file. I added these as constraints to the original MIP but it becomes infeasible. Could you help me figure out the problem? Thanks Regards Gaurav Gaurav Khanna Phd Student CSE Department,OSU Phone (office):614-292-7036 _______________________________________________ Help-glpk mailing list [email protected] http://lists.gnu.org/mailman/listinfo/help-glpk
