mirrors/z3
3
0
Fork 0
mirror of https://github.com/Z3Prover/z3 synced 2025-04-29 11:55:51 +00:00
Code Activity

fix a bug in the lar_solver::m_status update during push/pop

Browse source 
Signed-off-by: Lev Nachmanson <levnach@microsoft.com>

progress in gomory cut

Signed-off-by: Lev Nachmanson <levnach@microsoft.com>

the first version of Gomory cut, probably broken

Signed-off-by: Lev Nachmanson <levnach@microsoft.com>

rename a function

Signed-off-by: Lev Nachmanson <levnach@microsoft.com>

gomory cut worked on a toy example

Signed-off-by: Lev Nachmanson <levnach@microsoft.com>

track the set of integer variables that are not set to integer values

Signed-off-by: Lev Nachmanson <levnach@microsoft.com>
This commit is contained in:
Lev Nachmanson 2017-07-10 16:34:23 -07:00 • committed by Lev Nachmanson
parent 0164ea9abb
commit aba7dcab3e
21 changed files with 682 additions and 455 deletions
Download patch file Download diff file Expand all files Collapse all files

44
src/util/lp/lp_dual_simplex.hpp
View file

@ -22,23 +22,23 @@ namespace lp{
template <typename T, typename X> void lp_dual_simplex<T, X>::decide_on_status_after_stage1() {
switch (m_core_solver->get_status()) {
case OPTIMAL:
case lp_status::OPTIMAL:
if (this->m_settings.abs_val_is_smaller_than_artificial_tolerance(m_core_solver->get_cost())) {
this->m_status = FEASIBLE;
this->m_status = lp_status::FEASIBLE;
} else {
this->m_status = UNBOUNDED;
this->m_status = lp_status::UNBOUNDED;
}
break;
case DUAL_UNBOUNDED:
case lp_status::DUAL_UNBOUNDED:
lp_unreachable();
case ITERATIONS_EXHAUSTED:
this->m_status = ITERATIONS_EXHAUSTED;
case lp_status::ITERATIONS_EXHAUSTED:
this->m_status = lp_status::ITERATIONS_EXHAUSTED;
break;
case TIME_EXHAUSTED:
this->m_status = TIME_EXHAUSTED;
case lp_status::TIME_EXHAUSTED:
this->m_status = lp_status::TIME_EXHAUSTED;
break;
case FLOATING_POINT_ERROR:
this->m_status = FLOATING_POINT_ERROR;
case lp_status::FLOATING_POINT_ERROR:
this->m_status = lp_status::FLOATING_POINT_ERROR;
break;
default:
lp_unreachable();
@ -114,20 +114,20 @@ template <typename T, typename X> void lp_dual_simplex<T, X>::solve_for_stage2()
m_core_solver->solve_yB(m_core_solver->m_y);
m_core_solver->fill_reduced_costs_from_m_y_by_rows();
m_core_solver->start_with_initial_basis_and_make_it_dual_feasible();
m_core_solver->set_status(FEASIBLE);
m_core_solver->set_status(lp_status::FEASIBLE);
m_core_solver->solve();
switch (m_core_solver->get_status()) {
case OPTIMAL:
this->m_status = OPTIMAL;
case lp_status::OPTIMAL:
this->m_status = lp_status::OPTIMAL;
break;
case DUAL_UNBOUNDED:
this->m_status = INFEASIBLE;
case lp_status::DUAL_UNBOUNDED:
this->m_status = lp_status::INFEASIBLE;
break;
case TIME_EXHAUSTED:
this->m_status = TIME_EXHAUSTED;
case lp_status::TIME_EXHAUSTED:
this->m_status = lp_status::TIME_EXHAUSTED;
break;
case FLOATING_POINT_ERROR:
this->m_status = FLOATING_POINT_ERROR;
case lp_status::FLOATING_POINT_ERROR:
this->m_status = lp_status::FLOATING_POINT_ERROR;
break;
default:
lp_unreachable();
@ -166,7 +166,7 @@ template <typename T, typename X> void lp_dual_simplex<T, X>::stage1() {
m_core_solver->start_with_initial_basis_and_make_it_dual_feasible();
if (this->m_settings.abs_val_is_smaller_than_artificial_tolerance(m_core_solver->get_cost())) {
// skipping stage 1
m_core_solver->set_status(OPTIMAL);
m_core_solver->set_status(lp_status::OPTIMAL);
m_core_solver->set_total_iterations(0);
} else {
m_core_solver->solve();
@ -351,7 +351,7 @@ template <typename T, typename X> void lp_dual_simplex<T, X>::find_maximal_solut
this->flip_costs(); // do it for now, todo ( remove the flipping)
this->cleanup();
if (this->m_status == INFEASIBLE) {
if (this->m_status == lp_status::INFEASIBLE) {
return;
}
this->fill_matrix_A_and_init_right_side();
@ -361,7 +361,7 @@ template <typename T, typename X> void lp_dual_simplex<T, X>::find_maximal_solut
fill_first_stage_solver_fields();
copy_m_b_aside_and_set_it_to_zeros();
stage1();
if (this->m_status == FEASIBLE) {
if (this->m_status == lp_status::FEASIBLE) {
stage2();
}
}