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rm_lu

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This commit is contained in:
Lev Nachmanson 2023-03-04 15:15:08 -08:00
parent 25f103db1a
commit c251151d66
4 changed files with 9 additions and 163 deletions
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19
src/math/lp/lar_solver.cpp
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@ -795,24 +795,7 @@ namespace lp {
template <typename K, typename L>
void lar_solver::add_last_rows_to_lu(lp_primal_core_solver<K, L>& s) {
auto& f = s.m_factorization;
if (f != nullptr) {
auto columns_to_replace = f->get_set_of_columns_to_replace_for_add_last_rows(s.m_basis_heading);
if (f->m_refactor_counter + columns_to_replace.size() >= 200 || f->has_dense_submatrix()) {
delete f;
f = nullptr;
}
else {
f->add_last_rows_to_B(s.m_basis_heading, columns_to_replace);
}
}
if (f == nullptr) {
init_factorization(f, s.m_A, s.m_basis, m_settings);
if (f->get_status() != LU_status::OK) {
delete f;
f = nullptr;
}
}
lp_assert(false);
}

2
src/math/lp/lp_primal_core_solver.h
View file

@ -418,7 +418,7 @@ public:
// returns the number of iterations
unsigned solve();
lu<static_matrix<T, X>> * factorization() {return this->m_factorization;}
lu<static_matrix<T, X>> * factorization() {return nullptr;}
void delete_factorization();

59
src/math/lp/lu.h
View file

@ -305,66 +305,19 @@ public:
void calculate_Lwave_Pwave_for_last_row(unsigned lowest_row_of_the_bump, T diagonal_element);
void prepare_entering(unsigned entering, indexed_vector<T> & w) {
init_vector_w(entering, w);
lp_assert(false);
}
bool need_to_refactor() { return m_refactor_counter >= 200; }
bool need_to_refactor() { lp_assert(false);
return m_refactor_counter >= 200; }
void adjust_dimension_with_matrix_A() {
lp_assert(m_A.row_count() >= m_dim);
m_dim = m_A.row_count();
m_U.resize(m_dim);
m_Q.resize(m_dim);
m_R.resize(m_dim);
m_row_eta_work_vector.resize(m_dim);
lp_assert(false);
}
std::unordered_set<unsigned> get_set_of_columns_to_replace_for_add_last_rows(const vector<int> & heading) const {
std::unordered_set<unsigned> columns_to_replace;
unsigned m = m_A.row_count();
unsigned m_prev = m_U.dimension();
lp_assert(m_A.column_count() == heading.size());
for (unsigned i = m_prev; i < m; i++) {
for (const row_cell<T> & c : m_A.m_rows[i]) {
int h = heading[c.var()];
if (h < 0) {
continue;
}
columns_to_replace.insert(c.var());
}
}
return columns_to_replace;
}
void add_last_rows_to_B(const vector<int> & heading, const std::unordered_set<unsigned> & columns_to_replace) {
unsigned m = m_A.row_count();
lp_assert(m_A.column_count() == heading.size());
adjust_dimension_with_matrix_A();
m_w_for_extension.resize(m);
// At this moment the LU is correct
// for B extended by only by ones at the diagonal in the lower right corner
for (unsigned j :columns_to_replace) {
lp_assert(heading[j] >= 0);
replace_column_with_only_change_at_last_rows(j, heading[j]);
if (get_status() == LU_status::Degenerated)
break;
}
}
// column j is a basis column, and there is a change in the last rows
void replace_column_with_only_change_at_last_rows(unsigned j, unsigned column_to_change_in_U) {
init_vector_w(j, m_w_for_extension);
replace_column(zero_of_type<T>(), m_w_for_extension, column_to_change_in_U);
}
bool has_dense_submatrix() const {
for (auto m : m_tail)
if (m->is_dense())
return true;
return false;
}
}; // end of lu