lpkit.h

matlab整数规划工具箱

				   lower bound (or in the basis), it is FALSE
				   if the variable is at its upper bound */

  short     eta_valid;          /* TRUE if current Eta structures are valid */
  int       eta_alloc;          /* The allocated memory for Eta */
  int       eta_size;           /* The number of Eta columns */
  int       num_inv;            /* The number of real pivots */
  int       max_num_inv;        /* ## The number of real pivots between 
				   reinversions */
  REAL      *eta_value;         /* eta_alloc :The Structure containing the
				   values of Eta */
  int       *eta_row_nr;         /*  "     "  :The Structure containing the Row
				   indexes of Eta */
  int       *eta_col_end;       /* rows_alloc + MaxNumInv : eta_col_end[i] is
				   the start index of the next Eta column */

  short	    bb_rule;		/* what rule for selecting B&B variables */

  short     break_at_int;       /* TRUE if stop at first integer better than
                                   break_value */
  REAL      break_value;        

  REAL      obj_bound;          /* ## Objective function bound for speedup of 
				   B&B */
  int       iter;               /* The number of iterations in the simplex
				   solver (LP) */
  int       total_iter;         /* The total number of iterations (B&B)
				   (ILP) */
  int       max_level;          /* The Deepest B&B level of the last solution */
  int	    total_nodes;	/* total number of nodes processed in b&b */
  REAL      *solution;          /* sum_alloc+1 :The Solution of the last LP, 
				   0 = The Optimal Value, 
                                   1..rows The Slacks, 
				   rows+1..sum The Variables */
  REAL      *best_solution;     /*  "       "  :The Best 'Integer' Solution */
  REAL      *duals;             /* rows_alloc+1 :The dual variables of the
				   last LP */
  
  short     maximise;           /* TRUE if the goal is to maximise the 
				   objective function */
  short     floor_first;        /* TRUE if B&B does floor bound first */
  short     *ch_sign;           /* rows_alloc+1 :TRUE if the Row in the matrix
				   has changed sign 
                                   (a`x > b, x>=0) is translated to 
				   s + -a`x = -b with x>=0, s>=0) */ 

  short     scaling_used;	/* TRUE if scaling is used */
  short     columns_scaled;     /* TRUE is the columns are scaled too, Only use
		 		   if all variables are non-integer */
  REAL      *scale;             /* sum_alloc+1:0..Rows the scaling of the Rows,
				   Rows+1..Sum the scaling of the columns */

  int	    nr_lagrange;	/* Nr. of Langrangian relaxation constraints */
  REAL	    **lag_row;		/* NumLagrange, columns+1:Pointer to pointer of 
				   rows */
  REAL      *lag_rhs;		/* NumLagrange :Pointer to pointer of Rhs */
  REAL      *lambda;		/* NumLagrange :Lambda Values */
  short     *lag_con_type;      /* NumLagrange :TRUE if constraint type EQ */
  REAL      lag_bound;		/* the lagrangian lower bound */

  short     valid;		/* Has this lp pased the 'test' */
  REAL      infinite;           /* ## numerical stuff */
  REAL      epsilon;            /* ## */
  REAL      epsb;               /* ## */
  REAL      epsd;               /* ## */
  REAL      epsel;              /* ## */
  hashtable *rowname_hashtab;   /* hash table to store row names */
  hashtable *colname_hashtab;   /* hash table to store column names */
} lprec;



/* function interface for the user */

lprec *make_lp(int rows, int columns);
/* create and initialise a lprec structure
   defaults:
   Empty (Rows * Columns) matrix,
   Minimise the objective function
   constraints all type <=
   Upperbounds all Infinite
   no integer variables
   floor first in B&B
   no scaling
   default basis */

lprec *read_lp_file(FILE *input, short verbose, nstring lp_name);
/* create and read an .lp file from input (input must be open) */

void delete_lp(lprec *lp);
/* Remove problem from memory */

lprec *copy_lp(lprec *lp);
/* copy a lp structure */

void set_mat(lprec *lp, int row, int column, REAL value);
/* fill in element (Row,Column) of the matrix
   Row in [0..Rows] and Column in [1..Columns] */

void set_obj_fn(lprec *lp, REAL *row);
/* set the objective function (Row 0) of the matrix */
void str_set_obj_fn(lprec *lp, char *row);
/* The same, but with string input */

void add_constraint(lprec *lp, REAL *row, short constr_type, REAL rh);
/* Add a constraint to the problem,
   row is the constraint row,
   rh is the right hand side,
   constr_type is the type of constraint (LE (<=), GE(>=), EQ(=)) */
void str_add_constraint(lprec *lp, char *row_string ,short constr_type, REAL rh);
/* The same, but with string input */

void del_constraint(lprec *lp,int del_row);
/* Remove constrain nr del_row from the problem */

void add_lag_con(lprec *lp, REAL *row, short con_type, REAL rhs);
/* add a Lagrangian constraint of form Row' x contype Rhs */
void str_add_lag_con(lprec *lp, char *row, short con_type, REAL rhs);
/* The same, but with string input */

void add_column(lprec *lp, REAL *column);
/* Add a Column to the problem */
void str_add_column(lprec *lp, char *col_string);
/* The same, but with string input */

void del_column(lprec *lp, int column);
/* Delete a column */

void set_upbo(lprec *lp, int column, REAL value);
/* Set the upperbound of a variable */

void set_lowbo(lprec *lp, int column, REAL value);
/* Set the lowerbound of a variable */

void set_int(lprec *lp, int column, short must_be_int);
/* Set the type of variable, if must_be_int = TRUE then the variable must be integer */

void set_rh(lprec *lp, int row, REAL value);
/* Set the right hand side of a constraint row */

void set_rh_vec(lprec *lp, REAL *rh);
/* Set the right hand side vector */
void str_set_rh_vec(lprec *lp, char *rh_string);
/* The same, but with string input */

void set_maxim(lprec *lp);
/* maximise the objective function */

void set_minim(lprec *lp);
/* minimise the objective function */

void set_constr_type(lprec *lp, int row, short con_type);
/* Set the type of constraint in row Row (LE, GE, EQ) */

void set_row_name(lprec *lp, int row, nstring new_name);
/* Set the name of a constraint row, make sure that the name has < 25 characters */

void set_col_name(lprec *lp, int column, nstring new_name);
/* Set the name of a varaible column, make sure that the name has < 25 characters */

void auto_scale(lprec *lp);
/* Automatic scaling of the problem */

void unscale(lprec *lp);
/* Remove all scaling from the problem */

int solve(lprec *lp);
/* Solve the problem */

int lag_solve(lprec *lp, REAL start_bound, int num_iter, short verbose);
/* Do NumIter iterations with Lagrangian relaxation constraints */

void reset_basis(lprec *lp);
/* Reset the basis of a problem, can be usefull in case of degeneracy - JD */

REAL mat_elm(lprec *lp, int row, int column);
/* get a single element from the matrix */

void get_row(lprec *lp, int row_nr, REAL *row);
/* fill row with the row row_nr from the problem */

void get_column(lprec *lp, int col_nr, REAL *column);
/* fill column with the column col_nr from the problem */

void get_reduced_costs(lprec *lp, REAL *rc);
/* get the reduced costs vector */

short is_feasible(lprec *lp, REAL *values);
/* returns TRUE if the vector in values is a feasible solution to the lp */

short column_in_lp(lprec *lp, REAL *column);
/* returns TRUE if column is already present in lp. (Does not look at bounds
   and types, only looks at matrix values */

lprec *read_mps(FILE *input, short verbose);
/* read a MPS file */

void write_MPS(lprec *lp, FILE *output);
/* write a MPS file to output */

void write_LP(lprec *lp, FILE *output);
/* write a LP file to output */

void print_lp(lprec *lp);
/* Print the current problem, only usefull in very small (test) problems. 
  Shows the effect of scaling */

void print_solution(lprec *lp);
/* Print the solution to stdout */

void print_duals(lprec *lp);
/* Print the dual variables of the solution */

void print_scales(lprec *lp);
/* If scaling is used, print the scaling factors */




/* functions used internaly by the lp toolkit */
void error(char *format, ...);
void inc_mat_space(lprec *lp, int max_extra);
void inc_row_space(lprec *lp);
void inc_col_space(lprec *lp);
void unscale_columns(lprec *lp);
void btran(lprec *lp, REAL *row);
void invert(lprec *lp);
void presolve(lprec *lp);


/* define yyparse() to make compilers happy. There should be some system
   include file for this */
int yyparse(void);

#ifdef __cplusplus
};
#endif