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 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
  10  * License as published by the Free Software Foundation; either
  11  * version 2.1 of the License, or (at your option) any later version.
  12  *
  13  * This library is distributed in the hope that it will be useful,
  14  * but 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 02110-1301 USA
  21  */
  22
  23 \f
  24
  25 #include "libguile/__scm.h"
  26
  27 \f
  28 /*
  29  * A plugin interface for RNGs
  30  *
  31  * Using this interface, it is possible for the application to tell
  32  * libguile to use a different RNG.  This is desirable if it is
  33  * necessary to use the same RNG everywhere in the application in
  34  * order to prevent interference, if the application uses RNG
  35  * hardware, or if the application has special demands on the RNG.
  36  *
  37  * Look how the default generator is "plugged in" in scm_init_random().
  38  */
  39
  40 typedef struct scm_t_rstate {
  41   int reserved0;
  42   double reserved1;
  43   /* Custom fields follow here */
  44 } scm_t_rstate;
  45
  46 typedef struct scm_t_rng {
  47   size_t rstate_size;                               /* size of random state */
  48   unsigned long (*random_bits) (scm_t_rstate *state); /* gives 32 random bits */
  49   void (*init_rstate) (scm_t_rstate *state, const char *seed, int n);
  50   scm_t_rstate *(*copy_rstate) (scm_t_rstate *state);
  51 } scm_t_rng;
  52
  53 SCM_API scm_t_rng scm_the_rng;
  54
  55 \f
  56 /*
  57  * Default RNG
  58  */
  59 typedef struct scm_t_i_rstate {
  60   scm_t_rstate rstate;
  61   unsigned long w;
  62   unsigned long c;
  63 } scm_t_i_rstate;
  64
  65 SCM_API unsigned long scm_i_uniform32 (scm_t_i_rstate *);
  66 SCM_API void scm_i_init_rstate (scm_t_i_rstate *, const char *seed, int n);
  67 SCM_API scm_t_i_rstate *scm_i_copy_rstate (scm_t_i_rstate *);
  68
  69 \f
  70 /*
  71  * Random number library functions
  72  */
  73 SCM_API scm_t_rstate *scm_c_make_rstate (const char *, int);
  74 SCM_API scm_t_rstate *scm_c_default_rstate (void);
  75 #define scm_c_uniform32(RSTATE) scm_the_rng.random_bits (RSTATE)
  76 SCM_API double scm_c_uniform01 (scm_t_rstate *);
  77 SCM_API double scm_c_normal01 (scm_t_rstate *);
  78 SCM_API double scm_c_exp1 (scm_t_rstate *);
  79 SCM_API unsigned long scm_c_random (scm_t_rstate *, unsigned long m);
  80 SCM_API SCM scm_c_random_bignum (scm_t_rstate *, SCM m);
  81
  82 \f
  83 /*
  84  * Scheme level interface
  85  */
  86 SCM_API scm_t_bits scm_tc16_rstate;
  87 #define SCM_RSTATEP(obj) SCM_SMOB_PREDICATE (scm_tc16_rstate, obj)
  88 #define SCM_RSTATE(obj)  ((scm_t_rstate *) SCM_SMOB_DATA (obj))
  89
  90 SCM_API unsigned char scm_masktab[256];
  91
  92 SCM_API SCM scm_var_random_state;
  93 SCM_API SCM scm_random (SCM n, SCM state);
  94 SCM_API SCM scm_copy_random_state (SCM state);
  95 SCM_API SCM scm_seed_to_random_state (SCM seed);
  96 SCM_API SCM scm_random_uniform (SCM state);
  97 SCM_API SCM scm_random_solid_sphere_x (SCM v, SCM state);
  98 SCM_API SCM scm_random_hollow_sphere_x (SCM v, SCM state);
  99 SCM_API SCM scm_random_normal (SCM state);
 100 SCM_API SCM scm_random_normal_vector_x (SCM v, SCM state);
 101 SCM_API SCM scm_random_exp (SCM state);
 102 SCM_API void scm_init_random (void);
 103
 104 #endif  /* SCM_RANDOM_H */
 105
 106 /*
 107   Local Variables:
 108   c-file-style: "gnu"
 109   End:
 110 */