Hello,
I have the following questions in the MIP solver (please forgive my english).
1. Is there a guarantee on the order of columns in the original problem given to glp_intopt and the sub problem in at each node in the search tree (i am using MIP pre presolver here and also have <= constraints. glpk adds some auxillary columns). Or in other words how can I have a mapping column/row mapping from original problem and internal sub problem ?
2. Can I alter the variable values in callback (looking at the variables, I can suggest possible values of variables to converge faster to optimality. how can i communicate to solver these new values of variables) ?