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 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   int reserved0;
  43   double reserved1;
  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   unsigned long (*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 } scm_t_rng;
  53
  54 SCM_API scm_t_rng scm_the_rng;
  55
  56 \f
  57 /*
  58  * Default RNG
  59  */
  60 typedef struct scm_t_i_rstate {
  61   scm_t_rstate rstate;
  62   unsigned long w;
  63   unsigned long c;
  64 } scm_t_i_rstate;
  65
  66 SCM_INTERNAL unsigned long scm_i_uniform32 (scm_t_i_rstate *);
  67 SCM_INTERNAL void scm_i_init_rstate (scm_t_i_rstate *, const char *seed, int n);
  68 SCM_INTERNAL scm_t_i_rstate *scm_i_copy_rstate (scm_t_i_rstate *);
  69
  70 \f
  71 /*
  72  * Random number library functions
  73  */
  74 SCM_API scm_t_rstate *scm_c_make_rstate (const char *, int);
  75 SCM_API scm_t_rstate *scm_c_default_rstate (void);
  76 #define scm_c_uniform32(RSTATE) scm_the_rng.random_bits (RSTATE)
  77 SCM_API double scm_c_uniform01 (scm_t_rstate *);
  78 SCM_API double scm_c_normal01 (scm_t_rstate *);
  79 SCM_API double scm_c_exp1 (scm_t_rstate *);
  80 SCM_API unsigned long scm_c_random (scm_t_rstate *, unsigned long m);
  81 SCM_API SCM scm_c_random_bignum (scm_t_rstate *, SCM m);
  82
  83 \f
  84 /*
  85  * Scheme level interface
  86  */
  87 SCM_API scm_t_bits scm_tc16_rstate;
  88 #define SCM_RSTATEP(obj) SCM_SMOB_PREDICATE (scm_tc16_rstate, obj)
  89 #define SCM_RSTATE(obj)  ((scm_t_rstate *) SCM_SMOB_DATA (obj))
  90
  91 SCM_API unsigned char scm_masktab[256];
  92
  93 SCM_API SCM scm_var_random_state;
  94 SCM_API SCM scm_random (SCM n, SCM state);
  95 SCM_API SCM scm_copy_random_state (SCM state);
  96 SCM_API SCM scm_seed_to_random_state (SCM seed);
  97 SCM_API SCM scm_random_uniform (SCM state);
  98 SCM_API SCM scm_random_solid_sphere_x (SCM v, SCM state);
  99 SCM_API SCM scm_random_hollow_sphere_x (SCM v, SCM state);
 100 SCM_API SCM scm_random_normal (SCM state);
 101 SCM_API SCM scm_random_normal_vector_x (SCM v, SCM state);
 102 SCM_API SCM scm_random_exp (SCM state);
 103 SCM_INTERNAL void scm_init_random (void);
 104
 105 #endif  /* SCM_RANDOM_H */
 106
 107 /*
 108   Local Variables:
 109   c-file-style: "gnu"
 110   End:
 111 */