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testing simplex

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Signed-off-by: Nikolaj Bjorner <nbjorner@microsoft.com>
This commit is contained in:
Nikolaj Bjorner 2014-02-02 13:48:02 +01:00
parent 363af825c0
commit 9ba4b532f6
5 changed files with 199 additions and 51 deletions
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88
src/math/simplex/simplex_def.h
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@ -30,13 +30,26 @@ namespace simplex {
SASSERT(found);
);
scoped_numeral base_coeff(m);
scoped_eps_numeral value(em), tmp(em);
row r = M.mk_row();
for (unsigned i = 0; i < num_vars; ++i) {
M.add(r, coeffs[i], vars[i]);
if (vars[i] == base) {
m.set(base_coeff, coeffs[i]);
if (!m.is_zero(coeffs[i])) {
var_t v = vars[i];
M.add_var(r, coeffs[i], v);
if (v == base) {
m.set(base_coeff, coeffs[i]);
}
else {
SASSERT(!is_base(v));
em.mul(m_vars[v].m_value, coeffs[i], tmp);
em.add(value, tmp, value);
}
}
}
em.neg(value);
em.div(value, base_coeff, value);
SASSERT(!m.is_zero(base_coeff));
SASSERT(!m_vars[base].m_is_base);
while (m_row2base.size() <= r.id()) {
m_row2base.push_back(null_var);
}
@ -44,9 +57,20 @@ namespace simplex {
m_vars[base].m_base2row = r.id();
m_vars[base].m_is_base = true;
m.set(m_vars[base].m_base_coeff, base_coeff);
em.set(m_vars[base].m_value, value);
add_patch(base);
SASSERT(well_formed_row(r));
return r;
}
template<typename Ext>
void simplex<Ext>::add_patch(var_t v) {
SASSERT(is_base(v));
if (outside_bounds(v)) {
m_to_patch.insert(v);
}
}
template<typename Ext>
void simplex<Ext>::del_row(row const& r) {
m_vars[m_row2base[r.id()]].m_is_base = false;
@ -114,8 +138,12 @@ namespace simplex {
if (vi.m_lower_valid) out << em.to_string(vi.m_lower); else out << "-oo";
out << ":";
if (vi.m_upper_valid) out << em.to_string(vi.m_upper); else out << "oo";
out << "]";
if (vi.m_is_base) out << " b:" << vi.m_base2row;
out << "] ";
if (vi.m_is_base) out << "b:" << vi.m_base2row << " ";
col_iterator it = M.col_begin(i), end = M.col_end(i);
for (; it != end; ++it) {
out << "r" << it.get_row().id() << " ";
}
out << "\n";
}
}
@ -134,6 +162,7 @@ namespace simplex {
unsigned num_iterations = 0;
unsigned num_repeated = 0;
var_t v = null_var;
SASSERT(well_formed());
while ((v = select_var_to_fix()) != null_var) {
if (m_cancel || num_iterations > m_max_iterations) {
return l_undef;
@ -143,8 +172,8 @@ namespace simplex {
return l_false;
}
++num_iterations;
SASSERT(well_formed());
}
SASSERT(well_formed());
return l_true;
}
@ -188,18 +217,18 @@ namespace simplex {
m.set(x_jI.m_base_coeff, a_ij);
x_jI.m_is_base = true;
x_iI.m_is_base = false;
if (outside_bounds(x_j)) {
m_to_patch.insert(x_j);
}
add_patch(x_j);
SASSERT(well_formed_row(row(r_i)));
col_iterator it = M.col_begin(x_j), end = M.col_end(x_j);
scoped_numeral a_kj(m), g(m);
for (; it != end; ++it) {
row r_k = it.get_row();
if (r_k != r_i) {
if (r_k.id() != r_i) {
a_kj = it.get_row_entry().m_coeff;
a_kj.neg();
M.mul(r_k, a_ij);
M.add(r_k, a_kj, r_i);
M.add(r_k, a_kj, row(r_i));
var_t s = m_row2base[r_k.id()];
numeral& coeff = m_vars[s].m_base_coeff;
m.mul(coeff, a_ij, coeff);
@ -207,6 +236,7 @@ namespace simplex {
if (!m.is_one(g)) {
m.div(coeff, g, coeff);
}
SASSERT(well_formed_row(row(r_k)));
}
}
}
@ -240,8 +270,8 @@ namespace simplex {
void simplex<Ext>::update_value_core(var_t v, eps_numeral const& delta) {
eps_numeral& val = m_vars[v].m_value;
em.add(val, delta, val);
if (is_base(v) && outside_bounds(v)) {
m_to_patch.insert(v);
if (is_base(v)) {
add_patch(v);
}
}
@ -705,18 +735,7 @@ namespace simplex {
var_t s = m_row2base[i];
if (s == null_var) continue;
SASSERT(i == m_vars[s].m_base2row);
//
// TBD: extract coefficient of base variable and compare
// with m_vars[s].m_base_coeff;
//
// check that sum of assignments add up to 0 for every row.
row_iterator it = M.row_begin(row(i)), end = M.row_end(row(i));
scoped_eps_numeral sum(em), tmp(em);
for (; it != end; ++it) {
em.mul(m_vars[it->m_var].m_value, it->m_coeff, tmp);
sum += tmp;
}
SASSERT(em.is_zero(sum));
SASSERT(well_formed_row(row(i)));
}
return true;
}
@ -729,6 +748,25 @@ namespace simplex {
return true;
}
template<typename Ext>
bool simplex<Ext>::well_formed_row(row const& r) const {
//
// TBD: extract coefficient of base variable and compare
// with m_vars[s].m_base_coeff;
//
// check that sum of assignments add up to 0 for every row.
row_iterator it = M.row_begin(r), end = M.row_end(r);
scoped_eps_numeral sum(em), tmp(em);
for (; it != end; ++it) {
em.mul(m_vars[it->m_var].m_value, it->m_coeff, tmp);
sum += tmp;
}
SASSERT(em.is_zero(sum));
return true;
}
};
#endif