gad.h

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/* 
  GAd.h

  Gallager "A"

   Belief Network Decoder for the problem A x = z
                                                                */

/* Control parameters */
typedef struct { /* GAd_control */
#include "GAd_var_str.h"

  int verbose  ;

} GAd_control ;

typedef struct { /* GAd_param */
                  /* The sizes of everything.     */
  int M ;         /* number of rows in the matrix A */
  int N ;         /* number of columns in A         */
  int m , n ;     /* used to keep track of which row / column we are up to 
		     during complex optimizations */
                  /* The matrix A is represented in a list structure */
  alist_matrix *a ; /* unlike in fe.* , this is a pointer */
  int *bias ;      /* the prior on the s vector */ /********* needs setting! */
  unsigned char *z ;  
  unsigned char *xo ;  /* decoded x */
  unsigned char *t ;  /* current value of Ax */

unsigned char *q1 ; /* the pseudoposterior */

int  **pc1 ; /* probabilities contributed 
			    from each relationship pc0[1..N][1..umax] */
  int  *qc1 ; /* probabilities contributed by each bit to each 
			    relationship qc0[1..umax] */
  unsigned char **dqc ;         /* vote for 1 vs 0 */
  int  *qt1 ; /* product of probabilities from top
			    relationship qt0[1..N][1..umax] */
  int  *qb1 ; /* and from bottom */
  unsigned char **dpf , **dpr ; /* forward and reverse probabilities within
			    each relationship dpf[1..M][0..lmax+1] */

  unsigned char *x ;  /* the true binary state vector x[n] */

  int count ; /* count of number of differences between 
		 the state and the true answer */
  int count_high ; /* number of high bits in the s vector */
  int count_s ;    /* number of high bits in the true s vector */
  int true_s ;   /* whether the true s is supplied */
  double v ;  /* the score of the final state relative to the truth */
  int count_viol ; /* number of checks z that aren't coming out right */
  int not_decoded ; 
  GAd_control *c ; 
} GAd_param;


/* 
         memory and so forth 
                                     */

void GAd_allocate ( GAd_param * , GAd_control * ) ;
void GAd_free ( GAd_param * , GAd_control * ) ;
void GAd_defaults ( GAd_param * , GAd_control * ) ;
void   GAd_load_dqc ( GAd_param *p , GAd_control *c ) ;
void GAd_fprint_state ( GAd_param *p , GAd_control *c ) ;
void GAd_write_state ( GAd_param *p , GAd_control *c ) ;

/*
        the main routine
                                     */

int GAdecode ( GAd_param * , GAd_control * ) ;

void GAd_score_state ( GAd_param *p ) ;
void GAhorizontal_pass ( GAd_param *p ) ;
void GAvertical_pass ( GAd_param *p  , GAd_control *c ) ;