patternprob.h

   1 #ifndef PACHI_PATTERNPROB_H
   2 #define PACHI_PATTERNPROB_H
   3
   4 /* Pattern probability table. */
   5
   6 #include <math.h>
   7
   8 #include "board.h"
   9 #include "move.h"
  10 #include "pattern.h"
  11 #include "patternsp.h"
  12
  13
  14 /* The pattern probability table considers each pattern as a whole
  15  * (not dividing it to individual features) and stores probability
  16  * of the pattern being played. */
  17
  18 /* The table primary key is the pattern spatial (most distinctive
  19  * feature); within a single primary key chain, the entries are
  20  * unsorted (for now). */
  21
  22 struct pattern_prob {
  23         struct pattern p;
  24         floating_t prob;
  25         struct pattern_prob *next;
  26 };
  27
  28 struct pattern_pdict {
  29         struct pattern_config *pc;
  30
  31         struct pattern_prob **table; /* [pc->spat_dict->nspatials + 1] */
  32 };
  33
  34 /* Initialize the pdict data structure from a given file (pass NULL
  35  * to use default filename). Returns NULL if the file with patterns
  36  * has been found. */
  37 struct pattern_pdict *pattern_pdict_init(char *filename, struct pattern_config *pc);
  38
  39 /* Return probability associated with given pattern. Returns NaN if
  40  * the pattern cannot be found. */
  41 static floating_t pattern_prob(struct pattern_pdict *dict, struct pattern *p);
  42
  43 /* Evaluate patterns for all available moves. Stores found patterns
  44  * to pats[b->flen] and NON-normalized probability of each pattern
  45  * (or NaN in case of no match) to probs[b->flen]. Returns the sum
  46  * of all probabilities that can be used for normalization. */
  47 floating_t pattern_rate_moves(struct pattern_setup *pat,
  48                         struct board *b, enum stone color,
  49                         struct pattern *pats, floating_t *probs);
  50
  51 /* pattern_rate_moves() but for only some set of moves. */
  52 floating_t pattern_rate_some_moves(struct pattern_setup *pat,
  53                         struct board *b, enum stone color,
  54                         coord_t *coords, int coord_n,
  55                         struct pattern *pats, floating_t *probs);
  56
  57 /* Utility function - extract spatial id from a pattern. If the pattern
  58  * has no spatial feature, it is represented by the highest spatial id
  59  * plus one. */
  60 static uint32_t pattern2spatial(struct pattern_pdict *dict, struct pattern *p);
  61
  62
  63 static inline floating_t
  64 pattern_prob(struct pattern_pdict *dict, struct pattern *p)
  65 {
  66         uint32_t spi = pattern2spatial(dict, p);
  67         for (struct pattern_prob *pb = dict->table[spi]; pb; pb = pb->next)
  68                 if (pattern_eq(p, &pb->p))
  69                         return pb->prob;
  70         return NAN; // XXX: We assume quiet NAN existence
  71 }
  72
  73 static inline uint32_t
  74 pattern2spatial(struct pattern_pdict *dict, struct pattern *p)
  75 {
  76         for (int i = 0; i < p->n; i++)
  77                 if (p->f[i].id == FEAT_SPATIAL)
  78                         return p->f[i].payload;
  79         return dict->pc->spat_dict->nspatials;
  80 }
  81
  82 #endif