Thanks Raniere and Haroldo... but my problem is that GLP_IHEUR is always OFF (or FALSE) because the presolver always finds the optimal solution to the LP relaxation, so the callback is never "called". How can I bypass that problem?
Gioker 2013/4/9 Haroldo Santos <[email protected]> > Yes, it can be done using callbacks, but it would be nice if GLPK could: > > - read from command line (glpksol) > - enter in MathProg > > > > On Mon, Apr 8, 2013 at 10:36 PM, Raniere Silva <[email protected]>wrote: > >> Hi Giorgio, >> >> > I have a model to which I can provide a initial feasible solution. >> > How can I do that? >> >> I do long time ago (about 3 years). >> >> > Initially I tried with glp_read_mip: >> >> I didn't use that. Hope that some one can help you with that. >> >> > The second attempt was with the callback routine: >> > >> > void callback(glp_tree *tree, void *info){ >> > switch(glp_ios_reason(tree)) { >> > case GLP_IHEUR: glp_ios_heur_sol(tree, initsol);break; >> > default: break; >> > } >> > } >> > >> > where initsol was the integer feasible array solution. The code was: >> > ... >> > glp_iocp parm; >> > glp_init_iocp(&parm); >> > parm.cb_func = callback; >> > glp_simplex(mip, NULL); >> > glp_intopt(lp, &parm) >> > ... >> >> I used the callack function below: >> >> void callback(glp_tree *tree, void *info){ >> if(glp_ios_reason(tree) == GLP_IHEUR && glp_ios_curr_node(tree) == 1){ >> glp_ios_heur_sol(tree, info); >> } /* ----- end if ----- */ >> >> return ; >> } >> >> Raniere >> >> _______________________________________________ >> Help-glpk mailing list >> [email protected] >> https://lists.gnu.org/mailman/listinfo/help-glpk >> > > > > -- > ============================================================= > Haroldo Gambini Santos > Computing Department > Universidade Federal de Ouro Preto - UFOP > email: haroldo [at ] iceb.ufop.br > home/research page: www.decom.ufop.br/haroldo > > _______________________________________________ > Help-glpk mailing list > [email protected] > https://lists.gnu.org/mailman/listinfo/help-glpk > >
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