libguile/random.h

   1 /* classes: h_files */
   2
   3 #ifndef SCM_RANDOM_H
   4 #define SCM_RANDOM_H
   5
   6 /* Copyright (C) 1999,2000,2001, 2006, 2008, 2010 Free Software Foundation, Inc.
   7  *
   8  * This library is free software; you can redistribute it and/or
   9  * modify it under the terms of the GNU Lesser General Public License
  10  * as published by the Free Software Foundation; either version 3 of
  11  * the License, or (at your option) any later version.
  12  *
  13  * This library is distributed in the hope that it will be useful, but
  14  * WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  16  * Lesser General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU Lesser General Public
  19  * License along with this library; if not, write to the Free Software
  20  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
  21  * 02110-1301 USA
  22  */
  23
  24 \f
  25
  26 #include "libguile/__scm.h"
  27
  28 \f
  29 /*
  30  * A plugin interface for RNGs
  31  *
  32  * Using this interface, it is possible for the application to tell
  33  * libguile to use a different RNG.  This is desirable if it is
  34  * necessary to use the same RNG everywhere in the application in
  35  * order to prevent interference, if the application uses RNG
  36  * hardware, or if the application has special demands on the RNG.
  37  *
  38  * Look how the default generator is "plugged in" in scm_init_random().
  39  */
  40
  41 typedef struct scm_t_rstate {
  42   struct scm_t_rng *rng;
  43   double normal_next; /* For scm_c_normal01 */
  44   /* Custom fields follow here */
  45 } scm_t_rstate;
  46
  47 typedef struct scm_t_rng {
  48   size_t rstate_size;                               /* size of random state */
  49   scm_t_uint32 (*random_bits) (scm_t_rstate *state); /* gives 32 random bits */
  50   void (*init_rstate) (scm_t_rstate *state, const char *seed, int n);
  51   scm_t_rstate *(*copy_rstate) (scm_t_rstate *state);
  52   void (*from_datum) (scm_t_rstate *state, SCM datum);
  53   SCM (*to_datum) (scm_t_rstate *state);
  54 } scm_t_rng;
  55
  56 SCM_API scm_t_rng scm_the_rng;
  57
  58 \f
  59 /*
  60  * Random number library functions
  61  */
  62 SCM_API scm_t_rstate *scm_c_make_rstate (const char *, int);
  63 SCM_API scm_t_rstate *scm_c_rstate_from_datum (SCM datum);
  64 SCM_API scm_t_rstate *scm_c_default_rstate (void);
  65 #define scm_c_uniform32(RSTATE) ((RSTATE)->rng->random_bits (RSTATE))
  66 SCM_API double scm_c_uniform01 (scm_t_rstate *);
  67 SCM_API double scm_c_normal01 (scm_t_rstate *);
  68 SCM_API double scm_c_exp1 (scm_t_rstate *);
  69 SCM_API scm_t_uint32 scm_c_random (scm_t_rstate *, scm_t_uint32 m);
  70 SCM_API scm_t_uint64 scm_c_random64 (scm_t_rstate *state, scm_t_uint64 m);
  71 SCM_API SCM scm_c_random_bignum (scm_t_rstate *, SCM m);
  72
  73 \f
  74 /*
  75  * Scheme level interface
  76  */
  77 SCM_API scm_t_bits scm_tc16_rstate;
  78 #define SCM_RSTATEP(obj) SCM_SMOB_PREDICATE (scm_tc16_rstate, obj)
  79 #define SCM_RSTATE(obj)  ((scm_t_rstate *) SCM_SMOB_DATA (obj))
  80
  81 SCM_API unsigned char scm_masktab[256];
  82
  83 SCM_API SCM scm_var_random_state;
  84 SCM_API SCM scm_random (SCM n, SCM state);
  85 SCM_API SCM scm_copy_random_state (SCM state);
  86 SCM_API SCM scm_seed_to_random_state (SCM seed);
  87 SCM_API SCM scm_datum_to_random_state (SCM datum);
  88 SCM_API SCM scm_random_state_to_datum (SCM state);
  89 SCM_API SCM scm_random_state_from_platform (void);
  90 SCM_API SCM scm_random_uniform (SCM state);
  91 SCM_API SCM scm_random_solid_sphere_x (SCM v, SCM state);
  92 SCM_API SCM scm_random_hollow_sphere_x (SCM v, SCM state);
  93 SCM_API SCM scm_random_normal (SCM state);
  94 SCM_API SCM scm_random_normal_vector_x (SCM v, SCM state);
  95 SCM_API SCM scm_random_exp (SCM state);
  96 SCM_INTERNAL void scm_init_random (void);
  97
  98 SCM_INTERNAL void scm_i_random_bytes_from_platform (unsigned char *buf, size_t len);
  99
 100 #endif  /* SCM_RANDOM_H */
 101
 102 /*
 103   Local Variables:
 104   c-file-style: "gnu"
 105   End:
 106 */