> That's funny, I specifically issued the statement > control_params.presolve = GLP_ON; > before calling glp_intopt(). My understanding from the documentation > is that this would tell it to do the simplex pre-solve on its own. > Furthermore, the trace it showed on the screen indicated that it had in > fact found the LP solution already, before tackling the integer > programming problem.
Sorry, I did not notice that. Yes, if the mip presolver is enabled, there is no need to call glp_simplex. However, to obtain mip solution components you need to use api routine glp_mip_col_val rather than glp_get_col_prim (the latter retrieves basic lp solution, not mip solution). > Please see partial screen output below, from the original attempt. > Does the "Crashing..." part mean anything bad? That message means constructing an initial basis. In glpk 4.39 (which is the most recent version) it was replaced by a more friendly message. > As a follow-up attempt I worked in a glp_simplex() call prior to the > glp_intopt() call, just to see if that made a difference. In that > scenario it gave the LP solution as the integer solution, with > fractional values for x and y. I still haven't found a path that seems > to work. _______________________________________________ Help-glpk mailing list [email protected] http://lists.gnu.org/mailman/listinfo/help-glpk
