mirror of
https://github.com/Z3Prover/z3
synced 2025-04-27 19:05:51 +00:00
merge LRA
Signed-off-by: Nikolaj Bjorner <nbjorner@microsoft.com>
This commit is contained in:
Nikolaj Bjorner
parent
085d31dca2
commit
911b24784a
120 changed files with 23069 additions and 15 deletions
205
src/util/lp/random_updater.hpp
Normal file
205
src/util/lp/random_updater.hpp
Normal file
|
|
@ -0,0 +1,205 @@
|
|||
/*
|
||||
Copyright (c) 2017 Microsoft Corporation
|
||||
Author: Lev Nachmanson
|
||||
*/
|
||||
#include "util/lp/random_updater.h"
|
||||
#include "util/lp/static_matrix.h"
|
||||
#include "util/lp/lar_solver.h"
|
||||
#include "util/vector.h"
|
||||
namespace lean {
|
||||
|
||||
|
||||
|
||||
random_updater::random_updater(
|
||||
lar_core_solver & lar_core_solver,
|
||||
const vector<unsigned> & column_indices) : m_core_solver(lar_core_solver) {
|
||||
for (unsigned j : column_indices)
|
||||
add_column_to_sets(j);
|
||||
}
|
||||
|
||||
random_updater::interval random_updater::get_interval_of_non_basic_var(unsigned j) {
|
||||
interval ret;
|
||||
switch (m_core_solver.get_column_type(j)) {
|
||||
case column_type::free_column:
|
||||
break;
|
||||
case column_type::low_bound:
|
||||
ret.set_low_bound(m_core_solver.m_r_low_bounds[j]);
|
||||
break;
|
||||
case column_type::upper_bound:
|
||||
ret.set_upper_bound(m_core_solver.m_r_upper_bounds[j]);
|
||||
break;
|
||||
case column_type::boxed:
|
||||
case column_type::fixed:
|
||||
ret.set_low_bound(m_core_solver.m_r_low_bounds[j]);
|
||||
ret.set_upper_bound(m_core_solver.m_r_upper_bounds[j]);
|
||||
break;
|
||||
default:
|
||||
lean_assert(false);
|
||||
}
|
||||
return ret;
|
||||
}
|
||||
|
||||
void random_updater::diminish_interval_for_basic_var(numeric_pair<mpq>& nb_x, unsigned j,
|
||||
mpq & a,
|
||||
interval & r) {
|
||||
lean_assert(m_core_solver.m_r_heading[j] >= 0);
|
||||
numeric_pair<mpq> delta;
|
||||
lean_assert(a != zero_of_type<mpq>());
|
||||
switch (m_core_solver.get_column_type(j)) {
|
||||
case column_type::free_column:
|
||||
break;
|
||||
case column_type::low_bound:
|
||||
delta = m_core_solver.m_r_x[j] - m_core_solver.m_r_low_bounds[j];
|
||||
lean_assert(delta >= zero_of_type<numeric_pair<mpq>>());
|
||||
if (a > 0) {
|
||||
r.set_upper_bound(nb_x + delta / a);
|
||||
} else {
|
||||
r.set_low_bound(nb_x + delta / a);
|
||||
}
|
||||
break;
|
||||
case column_type::upper_bound:
|
||||
delta = m_core_solver.m_r_upper_bounds()[j] - m_core_solver.m_r_x[j];
|
||||
lean_assert(delta >= zero_of_type<numeric_pair<mpq>>());
|
||||
if (a > 0) {
|
||||
r.set_low_bound(nb_x - delta / a);
|
||||
} else {
|
||||
r.set_upper_bound(nb_x - delta / a);
|
||||
}
|
||||
break;
|
||||
case column_type::boxed:
|
||||
if (a > 0) {
|
||||
delta = m_core_solver.m_r_x[j] - m_core_solver.m_r_low_bounds[j];
|
||||
lean_assert(delta >= zero_of_type<numeric_pair<mpq>>());
|
||||
r.set_upper_bound(nb_x + delta / a);
|
||||
delta = m_core_solver.m_r_upper_bounds()[j] - m_core_solver.m_r_x[j];
|
||||
lean_assert(delta >= zero_of_type<numeric_pair<mpq>>());
|
||||
r.set_low_bound(nb_x - delta / a);
|
||||
} else { // a < 0
|
||||
delta = m_core_solver.m_r_upper_bounds()[j] - m_core_solver.m_r_x[j];
|
||||
lean_assert(delta >= zero_of_type<numeric_pair<mpq>>());
|
||||
r.set_upper_bound(nb_x - delta / a);
|
||||
delta = m_core_solver.m_r_x[j] - m_core_solver.m_r_low_bounds[j];
|
||||
lean_assert(delta >= zero_of_type<numeric_pair<mpq>>());
|
||||
r.set_low_bound(nb_x + delta / a);
|
||||
}
|
||||
break;
|
||||
case column_type::fixed:
|
||||
r.set_low_bound(nb_x);
|
||||
r.set_upper_bound(nb_x);
|
||||
break;
|
||||
default:
|
||||
lean_assert(false);
|
||||
}
|
||||
}
|
||||
|
||||
|
||||
void random_updater::diminish_interval_to_leave_basic_vars_feasible(numeric_pair<mpq> &nb_x, interval & r) {
|
||||
m_column_j->reset();
|
||||
unsigned i;
|
||||
mpq a;
|
||||
while (m_column_j->next(a, i)) {
|
||||
diminish_interval_for_basic_var(nb_x, m_core_solver.m_r_basis[i], a, r);
|
||||
if (r.is_empty())
|
||||
break;
|
||||
}
|
||||
}
|
||||
|
||||
random_updater::interval random_updater::find_shift_interval(unsigned j) {
|
||||
interval ret = get_interval_of_non_basic_var(j);
|
||||
diminish_interval_to_leave_basic_vars_feasible(m_core_solver.m_r_x[j], ret);
|
||||
return ret;
|
||||
}
|
||||
|
||||
void random_updater::shift_var(unsigned j, interval & r) {
|
||||
lean_assert(r.contains(m_core_solver.m_r_x[j]));
|
||||
lean_assert(m_core_solver.m_r_solver.column_is_feasible(j));
|
||||
auto old_x = m_core_solver.m_r_x[j];
|
||||
remove_value(old_x);
|
||||
auto new_val = m_core_solver.m_r_x[j] = get_random_from_interval(r);
|
||||
add_value(new_val);
|
||||
|
||||
lean_assert(r.contains(m_core_solver.m_r_x[j]));
|
||||
lean_assert(m_core_solver.m_r_solver.column_is_feasible(j));
|
||||
auto delta = m_core_solver.m_r_x[j] - old_x;
|
||||
|
||||
unsigned i;
|
||||
m_column_j->reset();
|
||||
mpq a;
|
||||
while(m_column_j->next(a, i)) {
|
||||
unsigned bj = m_core_solver.m_r_basis[i];
|
||||
m_core_solver.m_r_x[bj] -= a * delta;
|
||||
lean_assert(m_core_solver.m_r_solver.column_is_feasible(bj));
|
||||
}
|
||||
lean_assert(m_core_solver.m_r_solver.A_mult_x_is_off() == false);
|
||||
}
|
||||
|
||||
numeric_pair<mpq> random_updater::get_random_from_interval(interval & r) {
|
||||
unsigned rand = my_random();
|
||||
if ((!r.low_bound_is_set) && (!r.upper_bound_is_set))
|
||||
return numeric_pair<mpq>(rand % range, 0);
|
||||
if (r.low_bound_is_set && (!r.upper_bound_is_set))
|
||||
return r.low_bound + numeric_pair<mpq>(rand % range, 0);
|
||||
if ((!r.low_bound_is_set) && r.upper_bound_is_set)
|
||||
return r.upper_bound - numeric_pair<mpq>(rand % range, 0);
|
||||
lean_assert(r.low_bound_is_set && r.upper_bound_is_set);
|
||||
return r.low_bound + (rand % range) * (r.upper_bound - r.low_bound)/ range;
|
||||
}
|
||||
|
||||
void random_updater::random_shift_var(unsigned j) {
|
||||
m_column_j = m_core_solver.get_column_iterator(j);
|
||||
if (m_column_j->size() >= 50) {
|
||||
delete m_column_j;
|
||||
return;
|
||||
}
|
||||
interval interv = find_shift_interval(j);
|
||||
if (interv.is_empty()) {
|
||||
delete m_column_j;
|
||||
return;
|
||||
}
|
||||
|
||||
shift_var(j, interv);
|
||||
delete m_column_j;
|
||||
}
|
||||
|
||||
void random_updater::update() {
|
||||
for (auto j : m_var_set) {
|
||||
if (m_var_set.size() <= m_values.size()) {
|
||||
break; // we are done
|
||||
}
|
||||
random_shift_var(j);
|
||||
}
|
||||
}
|
||||
|
||||
void random_updater::add_value(numeric_pair<mpq>& v) {
|
||||
auto it = m_values.find(v);
|
||||
if (it == m_values.end()) {
|
||||
m_values[v] = 1;
|
||||
} else {
|
||||
it->second++;
|
||||
}
|
||||
}
|
||||
|
||||
void random_updater::remove_value(numeric_pair<mpq>& v) {
|
||||
auto it = m_values.find(v);
|
||||
lean_assert(it != m_values.end());
|
||||
it->second--;
|
||||
if (it->second == 0)
|
||||
m_values.erase(it);
|
||||
}
|
||||
|
||||
void random_updater::add_column_to_sets(unsigned j) {
|
||||
if (m_core_solver.m_r_heading[j] < 0) {
|
||||
m_var_set.insert(j);
|
||||
add_value(m_core_solver.m_r_x[j]);
|
||||
} else {
|
||||
unsigned row = m_core_solver.m_r_heading[j];
|
||||
for (auto row_c : m_core_solver.m_r_A.m_rows[row]) {
|
||||
unsigned cj = row_c.m_j;
|
||||
if (m_core_solver.m_r_heading[cj] < 0) {
|
||||
m_var_set.insert(cj);
|
||||
add_value(m_core_solver.m_r_x[cj]);
|
||||
}
|
||||
}
|
||||
}
|
||||
}
|
||||
}
|
||||
Loading…
Add table
Add a link
Reference in a new issue