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z3/src/math/lp/static_matrix_def.h
2023-03-08 10:27:05 -08:00

390 lines
12 KiB
C++

/*++
Copyright (c) 2017 Microsoft Corporation
Module Name:
<name>
Abstract:
<abstract>
Author:
Lev Nachmanson (levnach)
Revision History:
--*/
#pragma once
#include "util/vector.h"
#include <utility>
#include <set>
#include "math/lp/static_matrix.h"
namespace lp {
// each assignment for this matrix should be issued only once!!!
inline void addmul(double& r, double a, double b) { r += a*b; }
inline void addmul(mpq& r, mpq const& a, mpq const& b) { r.addmul(a, b); }
template <typename T, typename X>
void static_matrix<T, X>::init_row_columns(unsigned m, unsigned n) {
lp_assert(m_rows.size() == 0 && m_columns.size() == 0);
for (unsigned i = 0; i < m; i++) {
m_rows.push_back(row_strip<T>());
}
for (unsigned j = 0; j < n; j++) {
m_columns.push_back(column_strip());
}
}
template <typename T, typename X> void static_matrix<T, X>::scan_row_ii_to_offset_vector(const row_strip<T> & rvals) {
for (unsigned j = 0; j < rvals.size(); j++)
m_vector_of_row_offsets[rvals[j].var()] = j;
}
template <typename T, typename X> bool static_matrix<T, X>::pivot_row_to_row_given_cell(unsigned i, column_cell & c, unsigned pivot_col) {
unsigned ii = c.var();
lp_assert(i < row_count() && ii < column_count() && i != ii);
T alpha = -get_val(c);
lp_assert(!is_zero(alpha));
auto & rowii = m_rows[ii];
remove_element(rowii, rowii[c.offset()]);
scan_row_ii_to_offset_vector(rowii);
unsigned prev_size_ii = rowii.size();
// run over the pivot row and update row ii
for (const auto & iv : m_rows[i]) {
unsigned j = iv.var();
if (j == pivot_col) continue;
lp_assert(!is_zero(iv.coeff()));
int j_offs = m_vector_of_row_offsets[j];
if (j_offs == -1) { // it is a new element
T alv = alpha * iv.coeff();
add_new_element(ii, j, alv);
}
else {
addmul(rowii[j_offs].coeff(), iv.coeff(), alpha);
}
}
// clean the work vector
for (unsigned k = 0; k < prev_size_ii; k++) {
m_vector_of_row_offsets[rowii[k].var()] = -1;
}
// remove zeroes
for (unsigned k = rowii.size(); k-- > 0; ) {
if (is_zero(rowii[k].coeff()))
remove_element(rowii, rowii[k]);
}
return !rowii.empty();
}
// constructor that copies columns of the basis from A
template <typename T, typename X>
static_matrix<T, X>::static_matrix(static_matrix const &A, unsigned * /* basis */) :
m_vector_of_row_offsets(A.column_count(), numeric_traits<T>::zero()) {
unsigned m = A.row_count();
init_row_columns(m, m);
for (; m-- > 0; )
for (auto & col : A.m_columns[m])
set(col.var(), m, A.get_value_of_column_cell(col));
}
template <typename T, typename X> void static_matrix<T, X>::clear() {
m_vector_of_row_offsets.clear();
m_rows.clear();
m_columns.clear();
}
template <typename T, typename X> void static_matrix<T, X>::init_vector_of_row_offsets() {
m_vector_of_row_offsets.clear();
m_vector_of_row_offsets.resize(column_count(), -1);
}
template <typename T, typename X> void static_matrix<T, X>::init_empty_matrix(unsigned m, unsigned n) {
init_vector_of_row_offsets();
init_row_columns(m, n);
}
template <typename T, typename X> unsigned static_matrix<T, X>::lowest_row_in_column(unsigned col) {
lp_assert(col < column_count());
column_strip & colstrip = m_columns[col];
lp_assert(colstrip.size() > 0);
unsigned ret = 0;
for (auto & t : colstrip) {
if (t.var() > ret) {
ret = t.var();
}
}
return ret;
}
template <typename T, typename X> void static_matrix<T, X>::add_columns_at_the_end(unsigned delta) {
for (unsigned i = 0; i < delta; i++)
add_column();
}
template <typename T, typename X> void static_matrix<T, X>::forget_last_columns(unsigned how_many_to_forget) {
lp_assert(m_columns.size() >= how_many_to_forget);
unsigned j = column_count() - 1;
for (; how_many_to_forget-- > 0; ) {
remove_last_column(j --);
}
}
template <typename T, typename X> void static_matrix<T, X>::remove_last_column(unsigned j) {
column_strip & col = m_columns.back();
for (auto & it : col) {
auto & row = m_rows[it.var()];
unsigned offset = row.size() - 1;
for (auto row_it = row.rbegin(); row_it != row.rend(); row_it ++) {
if (row_it.var() == j) {
row.erase(row.begin() + offset);
break;
}
offset--;
}
}
m_columns.pop_back();
m_vector_of_row_offsets.pop_back();
}
template <typename T, typename X> void static_matrix<T, X>::set(unsigned row, unsigned col, T const & val) {
if (numeric_traits<T>::is_zero(val)) return;
lp_assert(row < row_count() && col < column_count());
auto & r = m_rows[row];
unsigned offs_in_cols = m_columns[col].size();
m_columns[col].push_back(make_column_cell(row, r.size()));
r.push_back(make_row_cell(col, offs_in_cols, val));
}
template <typename T, typename X>
std::set<std::pair<unsigned, unsigned>> static_matrix<T, X>::get_domain() {
std::set<std::pair<unsigned, unsigned>> ret;
for (unsigned i = 0; i < m_rows.size(); i++) {
for (auto &cell : m_rows[i]) {
ret.insert(std::make_pair(i, cell.var()));
}
}
return ret;
}
template <typename T, typename X> T static_matrix<T, X>::get_max_abs_in_row(unsigned row) const {
T ret = numeric_traits<T>::zero();
for (auto & t : m_rows[row]) {
T a = abs(t.coeff());
if (a > ret) {
ret = a;
}
}
return ret;
}
template <typename T, typename X> T static_matrix<T, X>::get_min_abs_in_row(unsigned row) const {
bool first_time = true;
T ret = numeric_traits<T>::zero();
for (auto & t : m_rows[row]) {
T a = abs(t.coeff());
if (first_time) {
ret = a;
first_time = false;
} else if (a < ret) {
ret = a;
}
}
return ret;
}
template <typename T, typename X> T static_matrix<T, X>::get_max_abs_in_column(unsigned column) const {
T ret = numeric_traits<T>::zero();
for (const auto & t : m_columns[column]) {
T a = abs(get_val(t));
if (a > ret) {
ret = a;
}
}
return ret;
}
template <typename T, typename X> T static_matrix<T, X>::get_min_abs_in_column(unsigned column) const {
bool first_time = true;
T ret = numeric_traits<T>::zero();
for (auto & t : m_columns[column]) {
T a = abs(get_val(t));
if (first_time) {
first_time = false;
ret = a;
} else if (a < ret) {
ret = a;
}
}
return ret;
}
#ifdef Z3DEBUG
template <typename T, typename X> void static_matrix<T, X>::check_consistency() {
std::unordered_map<std::pair<unsigned, unsigned>, T> by_rows;
for (unsigned i = 0; i < m_rows.size(); i++) {
for (auto & t : m_rows[i]) {
std::pair<unsigned, unsigned> p(i, t.var());
lp_assert(by_rows.find(p) == by_rows.end());
by_rows[p] = t.coeff();
}
}
std::unordered_map<std::pair<unsigned, unsigned>, T> by_cols;
for (unsigned i = 0; i < m_columns.size(); i++) {
for (auto & t : m_columns[i]) {
std::pair<unsigned, unsigned> p(t.var(), i);
lp_assert(by_cols.find(p) == by_cols.end());
by_cols[p] = get_val(t);
}
}
lp_assert(by_rows.size() == by_cols.size());
for (auto & t : by_rows) {
auto ic = by_cols.find(t.first);
lp_assert(ic != by_cols.end());
lp_assert(t.second == ic->second);
}
}
#endif
template <typename T, typename X> void static_matrix<T, X>::cross_out_row(unsigned k) {
#ifdef Z3DEBUG
check_consistency();
#endif
cross_out_row_from_columns(k, m_rows[k]);
fix_row_indices_in_each_column_for_crossed_row(k);
m_rows.erase(m_rows.begin() + k);
#ifdef Z3DEBUG
regen_domain();
check_consistency();
#endif
}
template <typename T, typename X> void static_matrix<T, X>::fix_row_indices_in_each_column_for_crossed_row(unsigned k) {
for (auto & column : m_columns)
for (auto& cell : column)
if (cell.var() > k)
cell.var()--;
}
template <typename T, typename X> void static_matrix<T, X>::cross_out_row_from_columns(unsigned k, row_strip<T> & row) {
for (auto & t : row) {
cross_out_row_from_column(t.var(), k);
}
}
template <typename T, typename X> void static_matrix<T, X>::cross_out_row_from_column(unsigned col, unsigned k) {
auto & s = m_columns[col];
for (unsigned i = 0; i < s.size(); i++) {
if (s[i].var() == k) {
s.erase(s.begin() + i);
break;
}
}
}
template <typename T, typename X> T static_matrix<T, X>::get_elem(unsigned i, unsigned j) const { // should not be used in efficient code !!!!
for (auto & t : m_rows[i]) {
if (t.var() == j) {
return t.coeff();
}
}
return numeric_traits<T>::zero();
}
template <typename T, typename X> T static_matrix<T, X>::get_balance() const {
T ret = zero_of_type<T>();
for (unsigned i = 0; i < row_count(); i++) {
ret += get_row_balance(i);
}
return ret;
}
template <typename T, typename X> T static_matrix<T, X>::get_row_balance(unsigned row) const {
T ret = zero_of_type<T>();
for (auto & t : m_rows[row]) {
if (numeric_traits<T>::is_zero(t.coeff())) continue;
T a = abs(t.coeff());
numeric_traits<T>::log(a);
ret += a * a;
}
return ret;
}
template <typename T, typename X> bool static_matrix<T, X>::is_correct() const {
for (auto & row : m_rows) {
std::unordered_set<unsigned> s;
for (auto & rc : row) {
if (s.find(rc.var()) != s.end())
return false;
s.insert(rc.var());
if (rc.var() >= m_columns.size())
return false;
if (rc.offset() >= m_columns[rc.var()].size())
return false;
if (rc.coeff() != get_val(m_columns[rc.var()][rc.offset()]))
return false;
if (is_zero(rc.coeff()))
return false;
}
}
for (auto & column : m_columns) {
std::unordered_set<unsigned> s;
for (auto & cc : column) {
if (s.find(cc.var()) != s.end())
return false;
s.insert(cc.var());
if (cc.var() >= m_rows.size())
return false;
if (cc.offset() >= m_rows[cc.var()].size())
return false;
if (get_val(cc) != m_rows[cc.var()][cc.offset()].coeff())
return false;
}
}
return true;
}
template <typename T, typename X>
void static_matrix<T, X>::remove_element(vector<row_cell<T>> & row_vals, row_cell<T> & row_el_iv) {
unsigned column_offset = row_el_iv.offset();
auto & column_vals = m_columns[row_el_iv.var()];
column_cell& cs = m_columns[row_el_iv.var()][column_offset];
unsigned row_offset = cs.offset();
if (column_offset != column_vals.size() - 1) {
auto & cc = column_vals[column_offset] = column_vals.back(); // copy from the tail
m_rows[cc.var()][cc.offset()].offset() = column_offset;
}
if (row_offset != row_vals.size() - 1) {
auto & rc = row_vals[row_offset] = row_vals.back(); // copy from the tail
m_columns[rc.var()][rc.offset()].offset() = row_offset;
}
column_vals.pop_back();
row_vals.pop_back();
}
template <typename T, typename X>
void static_matrix<T, X>::add_new_element(unsigned row, unsigned col, const T& val) {
auto & row_vals = m_rows[row];
auto & col_vals = m_columns[col];
unsigned row_el_offs = row_vals.size();
unsigned col_el_offs = col_vals.size();
row_vals.push_back(row_cell<T>(col, col_el_offs, val));
col_vals.push_back(column_cell(row, row_el_offs));
}
}