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qsat-opt

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Signed-off-by: Nikolaj Bjorner <nbjorner@microsoft.com>
This commit is contained in:
Nikolaj Bjorner 2016-04-28 21:31:16 -07:00
parent c414c6b5fd
commit c75fd02c95
5 changed files with 145 additions and 33 deletions
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16
src/math/simplex/model_based_opt.cpp
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@ -105,13 +105,10 @@ namespace opt {
var v = objective().m_vars.back();
unsigned x = v.m_id;
rational const& coeff = v.m_coeff;
rational const& x_val = m_var2value[x];
unsigned_vector const& row_ids = m_var2row_ids[x];
unsigned bound_row_index;
rational bound_coeff;
other.reset();
if (find_bound(x, bound_row_index, bound_coeff, other, coeff.is_pos())) {
row& r = m_rows[bound_row_index];
SASSERT(!bound_coeff.is_zero());
for (unsigned i = 0; i < other.size(); ++i) {
resolve(bound_row_index, bound_coeff, other[i], x);
@ -150,7 +147,7 @@ namespace opt {
if (a.is_zero()) {
// skip
}
else if (a.is_pos() == is_pos) {
else if (a.is_pos() == is_pos || r.m_type == t_eq) {
rational value = x_val - (r.m_value/a);
if (bound_row_index == UINT_MAX) {
lub_val = value;
@ -221,6 +218,7 @@ namespace opt {
SASSERT(a1 == get_coefficient(row_id1, x));
SASSERT(!a1.is_zero());
//
// row1 is of the form a1*x + t1 <~ 0
// row2 is of the form a2*x + t2 <~ 0
// assume that a1, a2 have the same sign.
@ -229,20 +227,22 @@ namespace opt {
// t1 - a1*t2/a2 <~~ 0
// where <~~ is strict if either <~1 or <~2 is strict.
// if a1 is negative, then ....
//
if (!m_rows[row_id2].m_alive) {
//
row& row2 = m_rows[row_id2];
if (!row2.m_alive) {
return false;
}
rational a2 = get_coefficient(row_id2, x);
if (a2.is_zero()) {
return false;
}
if (a1.is_pos() == a2.is_pos()) {
if (a1.is_pos() == a2.is_pos() || row2.m_type == t_eq) {
mul_add(row_id2, -a2/a1, row_id1);
return true;
}
else {
m_rows[row_id2].m_alive = false;
row2.m_alive = false;
return false;
}
}