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multirow/onerow/library/include/onerow/cplex_helper.hpp

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/*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#ifndef CPLEX_HELPER_HPP_
#define CPLEX_HELPER_HPP_
#include <vector>
#include <set>
#include "single_row_cut_generator.hpp"
using std::set;
using std::vector;
struct CplexRow {
int nz;
double pi_zero;
double *pi;
int *indices;
int depth;
int head;
double dynamism;
bool operator<(const CplexRow &other) const;
double get_violation(double *x);
void print(double *x);
};
/**
* This class provides useful methods for dealing with CPLEX.
*/
class CplexHelper {
private:
const CPXENVptr env;
const CPXLPptr lp;
bool *is_integer;
int n_cuts;
public:
/**
* Constructs a helper associated with the provided environment and problem.
*
* @param env Pointer to the ILOG CPLEX environment.
* @param lp Pointer to a CPLEX LP problem object.
*/
CplexHelper(CPXENVptr env, CPXLPptr lp);
~CplexHelper();
/**
* Adds the specified constraints to the model.
*
* @param cuts Set of constraints to add.
*/
void add_cut(Constraint *cut);
/**
* For each fractional row of the current tableau, adds as many single row
* cuts as possible. The cuts are generated by the provided generator class.
*
* @tparam Generator Class used to generate the cuts.
* @param max_rows The maximum number of rows to consider.
* @returns The number of cuts added.
*/
template<class Generator>
int add_single_row_cuts(int max_rows);
/**
* Gets a single row from the current tableau.
*
* @param index Index of the row to fetch.
* @returns The selected tableau row.
*/
Row* get_tableau_row(int index);
void read_basis();
void read_columns();
/**
* Solves the current problem, and prints some solution information.
*
* @returns The solution status, as returned by CPXgetstat.
*/
void solve(bool save_stats = false);
void dump_constraint(const Constraint &c, const char *msg = "");
void print_basis();
void flush_cuts();
void eta_print();
void eta_reset();
CplexRow constraint_to_cplex_row(const Constraint &cut);
Constraint cplex_row_to_constraint(const CplexRow &cplex_row);
void print_solution(double *x);
void find_good_rows(int max_rows);
int n_rows;
int n_cols;
double *ub;
double *lb;
int *cstat;
CplexRow *cplex_rows;
int eta_count;
int eta_total;
time_t eta_start;
set<CplexRow> cut_buffer;
double *first_solution;
double *current_solution;
double *optimal_solution;
long total_cuts;
int current_round;
int n_good_rows;
int *good_rows;
double *reduced_costs;
double cost_cutoff;
};
#include "cplex_helper.tpp"
#endif /* CPLEX_HELPER_HPP_ */