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experiment with substituting zeros in Horner&Grobner

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Signed-off-by: Lev Nachmanson <levnach@hotmail.com>
This commit is contained in:
Lev Nachmanson 2020-01-11 15:43:54 -08:00
parent 45c0f2225c
commit f0b530b0e4
4 changed files with 26 additions and 12 deletions
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12
src/math/lp/nla_common.cpp
View file

@ -125,9 +125,13 @@ unsigned common::random() {
// creates a nex expression for the coeff and var,
nex * common::nexvar(const rational & coeff, lpvar j, nex_creator& cn) {
SASSERT(!coeff.is_zero());
if (c().m_nla_settings.horner_subs_fixed() && c().var_is_fixed(j)) {
if (c().m_nla_settings.horner_subs_fixed() == 1 && c().var_is_fixed(j)) {
return cn.mk_scalar(coeff * c().m_lar_solver.column_lower_bound(j).x);
}
if (c().m_nla_settings.horner_subs_fixed() == 2 && c().var_is_fixed_to_zero(j)) {
return cn.mk_scalar(rational(0));
}
if (!c().is_monic_var(j)) {
c().insert_to_active_var_set(j);
return cn.mk_mul(cn.mk_scalar(coeff), cn.mk_var(j));
@ -138,7 +142,11 @@ nex * common::nexvar(const rational & coeff, lpvar j, nex_creator& cn) {
for (lpvar k : m.vars()) {
if (c().m_nla_settings.horner_subs_fixed() && c().var_is_fixed(k)) {
mf *= c().m_lar_solver.column_lower_bound(k).x;
} else {
} else if (c().m_nla_settings.horner_subs_fixed() == 2 &&
c().var_is_fixed_to_zero(j)) {
return cn.mk_scalar(rational(0));
}
else {
c().insert_to_active_var_set(k);
mf *= cn.mk_var(k);
CTRACE("nla_grobner", c().is_monic_var(k), c().print_var(k, tout) << "\n";);

8
src/math/lp/nla_core.cpp
View file

@ -1553,10 +1553,14 @@ const rational& core::val_of_fixed_var_with_deps(lpvar j, u_dependency*& dep) {
}
dd::pdd core::pdd_expr(const rational& c, lpvar j, u_dependency*& dep) {
if (m_nla_settings.grobner_subs_fixed() && var_is_fixed(j)) {
if (m_nla_settings.grobner_subs_fixed() == 1 && var_is_fixed(j)) {
return m_pdd_manager.mk_val(c * val_of_fixed_var_with_deps(j, dep));
}
if (m_nla_settings.grobner_subs_fixed() == 2 && var_is_fixed_to_zero(j)) {
return m_pdd_manager.mk_val(val_of_fixed_var_with_deps(j, dep));
}
if (!is_monic_var(j))
return c * m_pdd_manager.mk_var(j);
@ -1566,6 +1570,8 @@ dd::pdd core::pdd_expr(const rational& c, lpvar j, u_dependency*& dep) {
for (lpvar k : m.vars()) {
if (m_nla_settings.grobner_subs_fixed() && var_is_fixed(k)) {
r *= m_pdd_manager.mk_val(val_of_fixed_var_with_deps(k, dep));
} else if (m_nla_settings.grobner_subs_fixed() == 2 && var_is_fixed_to_zero(k)) {
return m_pdd_manager.mk_val(val_of_fixed_var_with_deps(k, dep));
} else {
r *= m_pdd_manager.mk_var(k);
}

4
src/math/lp/nla_params.pyg
View file

@ -4,7 +4,7 @@ def_module_params('nla',
('order', BOOL, True, 'run order lemmas'),
('tangents', BOOL, True, 'run tangent lemmas'),
('horner', BOOL, True, 'run horner\'s heuristic'),
('horner_subs_fixed', BOOL, False, 'substitute fixed variables by constants'),
('horner_subs_fixed', UINT, 2, '0 - no subs, 1 - substitute, 2 - substitute fixed zeros only'),
('horner_frequency', UINT, 4, 'horner\'s call frequency'),
('horner_row_length_limit', UINT, 10, 'row is disregarded by the heuristic if its length is longer than the value'),
('grobner', BOOL, True, 'run grobner\'s basis heuristic'),
@ -14,7 +14,7 @@ def_module_params('nla',
('grobner_max_simplified', UINT, 10000, 'grobner\'s maximum number of simplifications'),
('grobner_cnfl_to_report', UINT, 1, 'grobner\'s maximum number of conflicts to report'),
('gr_q', UINT, 8, 'grobner\'s quota'),
('grobner_subs_fixed', BOOL, False, 'substitute fixed variables by constants')
('grobner_subs_fixed', UINT, 2, '0 - no subs, 1 - substitute, 2 - substitute fixed zeros only')
))

14
src/math/lp/nla_settings.h
View file

@ -27,11 +27,11 @@ class nla_settings {
// how often to call the horner heuristic
unsigned m_horner_frequency;
unsigned m_horner_row_length_limit;
bool m_horner_subs_fixed;
unsigned m_horner_subs_fixed;
// grobner fields
bool m_run_grobner;
unsigned m_grobner_row_length_limit;
bool m_grobner_subs_fixed;
unsigned m_grobner_subs_fixed;
unsigned m_grobner_eqs_growth;
unsigned m_grobner_tree_size_growth;
unsigned m_grobner_expr_size_growth;
@ -44,7 +44,7 @@ public:
m_run_horner(true),
m_horner_frequency(4),
m_horner_row_length_limit(10),
m_horner_subs_fixed(true),
m_horner_subs_fixed(2),
m_run_grobner(true),
m_grobner_row_length_limit(50),
m_grobner_subs_fixed(false)
@ -64,16 +64,16 @@ public:
unsigned& horner_frequency() { return m_horner_frequency; }
unsigned horner_row_length_limit() const { return m_horner_row_length_limit; }
unsigned& horner_row_length_limit() { return m_horner_row_length_limit; }
bool horner_subs_fixed() const { return m_horner_subs_fixed; }
bool& horner_subs_fixed() { return m_horner_subs_fixed; }
unsigned horner_subs_fixed() const { return m_horner_subs_fixed; }
unsigned& horner_subs_fixed() { return m_horner_subs_fixed; }
bool run_grobner() const { return m_run_grobner; }
bool& run_grobner() { return m_run_grobner; }
unsigned grobner_row_length_limit() const { return m_grobner_row_length_limit; }
unsigned& grobner_row_length_limit() { return m_grobner_row_length_limit; }
bool grobner_subs_fixed() const { return m_grobner_subs_fixed; }
bool& grobner_subs_fixed() { return m_grobner_subs_fixed; }
unsigned grobner_subs_fixed() const { return m_grobner_subs_fixed; }
unsigned& grobner_subs_fixed() { return m_grobner_subs_fixed; }
unsigned grobner_tree_size_growth() const { return m_grobner_tree_size_growth; }
unsigned & grobner_tree_size_growth() { return m_grobner_tree_size_growth; }