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port grobner basis

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Signed-off-by: Lev Nachmanson <levnach@hotmail.com>
This commit is contained in:
Lev Nachmanson 2019-09-17 16:51:32 -07:00
parent 9ebb0327ba
commit 29cc2c5976
2 changed files with 158 additions and 19 deletions
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131
src/math/lp/nla_grobner.cpp
View file

@ -127,9 +127,52 @@ void nla_grobner::init() {
find_nl_cluster();
}
equation* nla_grobner::pick_next() {
bool nla_grobner::is_trivial(equation* eq) const {
return eq->m_monomials.empty();
}
bool nla_grobner:: is_better_choice(equation * eq1, equation * eq2) {
if (!eq2)
return true;
if (is_trivial(eq1))
return true;
if (is_trivial(eq2))
return false;
if (eq1->m_monomials[0]->get_degree() < eq2->m_monomials[0]->get_degree())
return true;
if (eq1->m_monomials[0]->get_degree() > eq2->m_monomials[0]->get_degree())
return false;
return eq1->m_monomials.size() < eq2->m_monomials.size();
}
void nla_grobner::del_equation(equation * eq) {
SASSERT(false);
return nullptr;
/*
m_processed.erase(eq);
m_to_process.erase(eq);
SASSERT(m_equations_to_delete[eq->m_bidx] == eq);
m_equations_to_delete[eq->m_bidx] = 0;
del_monomials(eq->m_monomials);
dealloc(eq);
*/
}
equation* nla_grobner::pick_next() {
equation * r = nullptr;
ptr_buffer<equation> to_delete;
for (equation * curr : m_to_process) {
if (is_trivial(curr))
to_delete.push_back(curr);
else if (is_better_choice(curr, r))
r = curr;
}
for (equation * e : to_delete)
del_equation(e);
if (r)
m_to_process.erase(r);
TRACE("grobner", tout << "selected equation: "; if (!r) tout << "<null>\n"; else display_equation(tout, *r););
return r;
}
equation* nla_grobner::simplify_using_processed(equation* eq) {
@ -197,31 +240,101 @@ bool nla_grobner::compute_basis_loop(){
return false;
}
void nla_grobner::set_gb_exhausted(){ SASSERT(false); }
void nla_grobner::update_statistics(){
SASSERT(false);
void nla_grobner::set_gb_exhausted(){
NOT_IMPLEMENTED_YET();
}
bool nla_grobner::find_conflict(){ SASSERT(false);
void nla_grobner::update_statistics(){
/* todo : implement
m_stats.m_gb_simplify += gb.m_stats.m_simplify;
m_stats.m_gb_superpose += gb.m_stats.m_superpose;
m_stats.m_gb_num_processed += gb.m_stats.m_num_processed;
m_stats.m_gb_compute_basis++;*/
}
// Scan the grobner basis eqs, and look for inconsistencies.
bool nla_grobner::find_conflict(ptr_vector<equation>& eqs){
eqs.reset();
get_equations(eqs);
TRACE("grobner_bug", tout << "after gb\n";);
for (equation* eq : eqs) {
TRACE("grobner_bug", display_equation(tout, *eq););
if (is_inconsistent(eq) || is_inconsistent2(eq))
return true;
}
return false;
}
bool nla_grobner::push_calculation_forward(){ SASSERT(false);
bool nla_grobner::is_inconsistent(equation*) {
NOT_IMPLEMENTED_YET();
return false;
}
bool nla_grobner::is_inconsistent2(equation*) {
NOT_IMPLEMENTED_YET();
return false;
}
template <typename T, typename V>
void copy_to(const T& source, V& target ) {
for (auto e : source)
target.push_back(e);
}
void nla_grobner::get_equations(ptr_vector<equation>& result) {
copy_to(m_processed, result);
copy_to(m_to_process, result);
}
bool nla_grobner::push_calculation_forward(){
NOT_IMPLEMENTED_YET();
return false;
}
void nla_grobner::grobner_lemmas() {
c().lp_settings().stats().m_grobner_calls++;
init();
ptr_vector<equation> eqs;
do {
TRACE("nla_gb", tout << "before:\n"; display(tout););
compute_basis();
update_statistics();
TRACE("nla_gb", tout << "after:\n"; display(tout););
if (find_conflict())
if (find_conflict(eqs))
return;
}
while(push_calculation_forward());
}
void nla_grobner:: del_equations(unsigned old_size) {
SASSERT(m_equations_to_delete.size() >= old_size);
equation_vector::iterator it = m_equations_to_delete.begin();
equation_vector::iterator end = m_equations_to_delete.end();
it += old_size;
for (; it != end; ++it) {
equation * eq = *it;
if (eq)
del_equation(eq);
}
m_equations_to_delete.shrink(old_size);
}
void nla_grobner::display_equations(std::ostream & out, equation_set const & v, char const * header) const {
NOT_IMPLEMENTED_YET();
}
void nla_grobner::display_equation(std::ostream & out, equation const & eq) const {
NOT_IMPLEMENTED_YET();
}
void nla_grobner::display_monomial(std::ostream & out, monomial const & m) const {
NOT_IMPLEMENTED_YET();
}
void nla_grobner::display(std::ostream & out) const {
NOT_IMPLEMENTED_YET();
}
} // end of nla namespace

46
src/math/lp/nla_grobner.h
View file

@ -36,6 +36,18 @@ struct grobner_stats {
};
struct monomial {
rational m_coeff;
svector<lpvar> m_vars; //!< sorted variables
friend class grobner;
friend struct monomial_lt;
monomial() {}
public:
rational const & get_coeff() const { return m_coeff; }
unsigned get_degree() const { return m_vars.size(); }
unsigned get_size() const { return get_degree(); }
lpvar get_var(unsigned idx) const { return m_vars[idx]; }
};
class equation {
@ -43,8 +55,8 @@ class equation {
unsigned m_bidx:31; //!< position at m_equations_to_delete
unsigned m_lc:1; //!< true if equation if a linear combination of the input equations.
ptr_vector<monomial> m_monomials; //!< sorted monomials
v_dependency * m_dep; //!< justification for the equality
friend class grobner;
v_dependency * m_dep; //!< justification for the equality
friend class nla_grobner;
equation() {}
public:
unsigned get_num_monomials() const { return m_monomials.size(); }
@ -70,14 +82,15 @@ enum class var_weight {
class nla_grobner : common {
typedef obj_hashtable<equation> equation_set;
typedef ptr_vector<equation> equation_vector;
equation_vector m_equations_to_unfreeze;
equation_vector m_equations_to_delete;
lp::int_set m_rows;
lp::int_set m_active_vars;
svector<var_weight> m_active_vars_weights;
unsigned m_num_of_equations;
grobner_stats m_stats;
// fields
equation_vector m_equations_to_unfreeze;
equation_vector m_equations_to_delete;
lp::int_set m_rows;
lp::int_set m_active_vars;
svector<var_weight> m_active_vars_weights;
unsigned m_num_of_equations;
grobner_stats m_stats;
equation_set m_processed;
equation_set m_to_process;
public:
@ -93,7 +106,9 @@ private:
var_weight get_var_weight(lpvar) const;
void compute_basis();
void update_statistics();
bool find_conflict();
bool find_conflict(ptr_vector<equation>& eqs);
bool is_inconsistent(equation*);
bool is_inconsistent2(equation*);
bool push_calculation_forward();
void compute_basis_init();
bool compute_basis_loop();
@ -106,5 +121,16 @@ private:
bool canceled() { return false; } // todo, implement
void superpose(equation * eq1, equation * eq2);
void superpose(equation * eq);
bool is_trivial(equation* ) const;
bool is_better_choice(equation * eq1, equation * eq2);
void del_equations(unsigned old_size);
void del_equation(equation * eq);
void display_equations(std::ostream & out, equation_set const & v, char const * header) const;
void display_equation(std::ostream & out, equation const & eq) const;
void display_monomial(std::ostream & out, monomial const & m) const;
void display(std::ostream & out) const;
void get_equations(ptr_vector<equation>& eqs);
}; // end of grobner
}