-/* Copyright (C) 1999,2000,2001 Free Software Foundation, Inc.
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2, or (at your option)
- * any later version.
+/* Copyright (C) 1999,2000,2001, 2003, 2005, 2006, 2009, 2010 Free Software Foundation, Inc.
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public License
+ * as published by the Free Software Foundation; either version 3 of
+ * the License, or (at your option) any later version.
*
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU General Public License for more details.
+ * This library is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * Lesser General Public License for more details.
*
- * You should have received a copy of the GNU General Public License
- * along with this software; see the file COPYING. If not, write to
- * the Free Software Foundation, Inc., 59 Temple Place, Suite 330,
- * Boston, MA 02111-1307 USA
- *
- * As a special exception, the Free Software Foundation gives permission
- * for additional uses of the text contained in its release of GUILE.
- *
- * The exception is that, if you link the GUILE library with other files
- * to produce an executable, this does not by itself cause the
- * resulting executable to be covered by the GNU General Public License.
- * Your use of that executable is in no way restricted on account of
- * linking the GUILE library code into it.
- *
- * This exception does not however invalidate any other reasons why
- * the executable file might be covered by the GNU General Public License.
- *
- * This exception applies only to the code released by the
- * Free Software Foundation under the name GUILE. If you copy
- * code from other Free Software Foundation releases into a copy of
- * GUILE, as the General Public License permits, the exception does
- * not apply to the code that you add in this way. To avoid misleading
- * anyone as to the status of such modified files, you must delete
- * this exception notice from them.
- *
- * If you write modifications of your own for GUILE, it is your choice
- * whether to permit this exception to apply to your modifications.
- * If you do not wish that, delete this exception notice. */
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+ * 02110-1301 USA
+ */
/* Author: Mikael Djurfeldt <djurfeldt@nada.kth.se> */
+#ifdef HAVE_CONFIG_H
+# include <config.h>
+#endif
+
#include "libguile/_scm.h"
+#include <gmp.h>
#include <stdio.h>
#include <math.h>
#include <string.h>
#include "libguile/numbers.h"
#include "libguile/feature.h"
#include "libguile/strings.h"
-#include "libguile/unif.h"
+#include "libguile/arrays.h"
+#include "libguile/srfi-4.h"
#include "libguile/vectors.h"
+#include "libguile/generalized-vectors.h"
#include "libguile/validate.h"
#include "libguile/random.h"
* (http://stat.fsu.edu/~geo/diehard.html)
*/
+typedef struct scm_t_i_rstate {
+ scm_t_rstate rstate;
+ scm_t_uint32 w;
+ scm_t_uint32 c;
+} scm_t_i_rstate;
+
+
#define A 2131995753UL
#ifndef M_PI
#define M_PI 3.14159265359
#endif
-#if SIZEOF_LONG > 4
-#if SIZEOF_INT > 4
-#define LONG32 unsigned short
-#else
-#define LONG32 unsigned int
-#endif
-#define LONG64 unsigned long
-#else
-#define LONG32 unsigned long
-#ifdef __MINGW32__
-#define LONG64 unsigned __int64
-#else
-#define LONG64 unsigned long long
-#endif
-#endif
-
-#if SIZEOF_LONG > 4 || defined (HAVE_LONG_LONGS)
-
-unsigned long
-scm_i_uniform32 (scm_t_i_rstate *state)
-{
- LONG64 x = (LONG64) A * state->w + state->c;
- LONG32 w = x & 0xffffffffUL;
- state->w = w;
- state->c = x >> 32L;
- return w;
-}
-
-#else
-
-/* ww This is a portable version of the same RNG without 64 bit
- * * aa arithmetic.
- * ----
- * xx It is only intended to provide identical behaviour on
- * xx platforms without 8 byte longs or long longs until
- * xx someone has implemented the routine in assembler code.
- * xxcc
- * ----
- * ccww
- */
-
-#define L(x) ((x) & 0xffff)
-#define H(x) ((x) >> 16)
-
-unsigned long
-scm_i_uniform32 (scm_t_i_rstate *state)
+static scm_t_uint32
+scm_i_uniform32 (scm_t_rstate *state)
{
- LONG32 x1 = L (A) * L (state->w);
- LONG32 x2 = L (A) * H (state->w);
- LONG32 x3 = H (A) * L (state->w);
- LONG32 w = L (x1) + L (state->c);
- LONG32 m = H (x1) + L (x2) + L (x3) + H (state->c) + H (w);
- LONG32 x4 = H (A) * H (state->w);
- state->w = w = (L (m) << 16) + L (w);
- state->c = H (x2) + H (x3) + x4 + H (m);
+ scm_t_i_rstate *istate = (scm_t_i_rstate*) state;
+ scm_t_uint64 x = (scm_t_uint64) A * istate->w + istate->c;
+ scm_t_uint32 w = x & 0xffffffffUL;
+ istate->w = w;
+ istate->c = x >> 32L;
return w;
}
-#endif
-
-void
-scm_i_init_rstate (scm_t_i_rstate *state, char *seed, int n)
+static void
+scm_i_init_rstate (scm_t_rstate *state, const char *seed, int n)
{
- LONG32 w = 0L;
- LONG32 c = 0L;
+ scm_t_i_rstate *istate = (scm_t_i_rstate*) state;
+ scm_t_uint32 w = 0L;
+ scm_t_uint32 c = 0L;
int i, m;
for (i = 0; i < n; ++i)
{
else
c += seed[i] << (8 * (m - 4));
}
- if ((w == 0 && c == 0) || (w == 0xffffffffUL && c == A - 1))
+ if ((w == 0 && c == 0) || (w == -1 && c == A - 1))
++c;
- state->w = w;
- state->c = c;
+ istate->w = w;
+ istate->c = c;
+}
+
+static scm_t_rstate *
+scm_i_copy_rstate (scm_t_rstate *state)
+{
+ scm_t_rstate *new_state;
+
+ new_state = scm_gc_malloc_pointerless (state->rng->rstate_size,
+ "random-state");
+ return memcpy (new_state, state, state->rng->rstate_size);
}
-scm_t_i_rstate *
-scm_i_copy_rstate (scm_t_i_rstate *state)
+SCM_SYMBOL(scm_i_rstate_tag, "multiply-with-carry");
+
+static void
+scm_i_rstate_from_datum (scm_t_rstate *state, SCM value)
+#define FUNC_NAME "scm_i_rstate_from_datum"
{
- scm_t_rstate *new_state = scm_malloc (scm_the_rng.rstate_size);
- if (new_state == 0)
- scm_memory_error ("rstate");
- return memcpy (new_state, state, scm_the_rng.rstate_size);
+ scm_t_i_rstate *istate = (scm_t_i_rstate*) state;
+ scm_t_uint32 w, c;
+ long length;
+
+ SCM_VALIDATE_LIST_COPYLEN (SCM_ARG1, value, length);
+ SCM_ASSERT (length == 3, value, SCM_ARG1, FUNC_NAME);
+ SCM_ASSERT (scm_is_eq (SCM_CAR (value), scm_i_rstate_tag),
+ value, SCM_ARG1, FUNC_NAME);
+ SCM_VALIDATE_UINT_COPY (SCM_ARG1, SCM_CADR (value), w);
+ SCM_VALIDATE_UINT_COPY (SCM_ARG1, SCM_CADDR (value), c);
+
+ istate->w = w;
+ istate->c = c;
+}
+#undef FUNC_NAME
+
+static SCM
+scm_i_rstate_to_datum (scm_t_rstate *state)
+{
+ scm_t_i_rstate *istate = (scm_t_i_rstate*) state;
+ return scm_list_3 (scm_i_rstate_tag,
+ scm_from_uint32 (istate->w),
+ scm_from_uint32 (istate->c));
}
\f
*/
scm_t_rstate *
-scm_c_make_rstate (char *seed, int n)
+scm_c_make_rstate (const char *seed, int n)
{
- scm_t_rstate *state = scm_malloc (scm_the_rng.rstate_size);
- if (state == 0)
- scm_memory_error ("rstate");
- state->reserved0 = 0;
- scm_the_rng.init_rstate (state, seed, n);
+ scm_t_rstate *state;
+
+ state = scm_gc_malloc_pointerless (scm_the_rng.rstate_size,
+ "random-state");
+ state->rng = &scm_the_rng;
+ state->normal_next = 0.0;
+ state->rng->init_rstate (state, seed, n);
return state;
}
+scm_t_rstate *
+scm_c_rstate_from_datum (SCM datum)
+{
+ scm_t_rstate *state;
+
+ state = scm_gc_malloc_pointerless (scm_the_rng.rstate_size,
+ "random-state");
+ state->rng = &scm_the_rng;
+ state->normal_next = 0.0;
+ state->rng->from_datum (state, datum);
+ return state;
+}
scm_t_rstate *
scm_c_default_rstate ()
#define FUNC_NAME "scm_c_default_rstate"
{
- SCM state = SCM_CDR (scm_var_random_state);
+ SCM state = SCM_VARIABLE_REF (scm_var_random_state);
if (!SCM_RSTATEP (state))
SCM_MISC_ERROR ("*random-state* contains bogus random state", SCM_EOL);
return SCM_RSTATE (state);
#undef FUNC_NAME
-inline double
+double
scm_c_uniform01 (scm_t_rstate *state)
{
- double x = (double) scm_the_rng.random_bits (state) / (double) 0xffffffffUL;
- return ((x + (double) scm_the_rng.random_bits (state))
+ double x = (double) state->rng->random_bits (state) / (double) 0xffffffffUL;
+ return ((x + (double) state->rng->random_bits (state))
/ (double) 0xffffffffUL);
}
double
scm_c_normal01 (scm_t_rstate *state)
{
- if (state->reserved0)
+ if (state->normal_next != 0.0)
{
- state->reserved0 = 0;
- return state->reserved1;
+ double ret = state->normal_next;
+
+ state->normal_next = 0.0;
+
+ return ret;
}
else
{
a = 2.0 * M_PI * scm_c_uniform01 (state);
n = r * sin (a);
- state->reserved1 = r * cos (a);
- state->reserved0 = 1;
+ state->normal_next = r * cos (a);
return n;
}
unsigned char scm_masktab[256];
-unsigned long
-scm_c_random (scm_t_rstate *state, unsigned long m)
+static inline scm_t_uint32
+scm_i_mask32 (scm_t_uint32 m)
{
- unsigned int r, mask;
- mask = (m < 0x100
+ return (m < 0x100
? scm_masktab[m]
: (m < 0x10000
? scm_masktab[m >> 8] << 8 | 0xff
: (m < 0x1000000
? scm_masktab[m >> 16] << 16 | 0xffff
: scm_masktab[m >> 24] << 24 | 0xffffff)));
- while ((r = scm_the_rng.random_bits (state) & mask) >= m);
+}
+
+scm_t_uint32
+scm_c_random (scm_t_rstate *state, scm_t_uint32 m)
+{
+ scm_t_uint32 r, mask = scm_i_mask32 (m);
+ while ((r = state->rng->random_bits (state) & mask) >= m);
return r;
}
+scm_t_uint64
+scm_c_random64 (scm_t_rstate *state, scm_t_uint64 m)
+{
+ scm_t_uint64 r;
+ scm_t_uint32 mask;
+
+ if (m <= SCM_T_UINT32_MAX)
+ return scm_c_random (state, (scm_t_uint32) m);
+
+ mask = scm_i_mask32 (m >> 32);
+ while ((r = ((scm_t_uint64) (state->rng->random_bits (state) & mask) << 32)
+ | state->rng->random_bits (state)) >= m)
+ ;
+ return r;
+}
+
+/*
+ SCM scm_c_random_bignum (scm_t_rstate *state, SCM m)
+
+ Takes a random state (source of random bits) and a bignum m.
+ Returns a bignum b, 0 <= b < m.
+
+ It does this by allocating a bignum b with as many base 65536 digits
+ as m, filling b with random bits (in 32 bit chunks) up to the most
+ significant 1 in m, and, finally checking if the resultant b is too
+ large (>= m). If too large, we simply repeat the process again. (It
+ is important to throw away all generated random bits if b >= m,
+ otherwise we'll end up with a distorted distribution.)
+
+*/
+
SCM
scm_c_random_bignum (scm_t_rstate *state, SCM m)
{
- SCM b;
- int i, nd;
- LONG32 *bits, mask, w;
- nd = SCM_NUMDIGS (m);
- /* calculate mask for most significant digit */
-#if SIZEOF_INT == 4
- /* 16 bit digits */
- if (nd & 1)
- {
- /* fix most significant 16 bits */
- unsigned short s = SCM_BDIGITS (m)[nd - 1];
- mask = s < 0x100 ? scm_masktab[s] : scm_masktab[s >> 8] << 8 | 0xff;
- }
- else
-#endif
- {
- /* fix most significant 32 bits */
-#if SIZEOF_INT == 4
- w = SCM_BDIGITS (m)[nd - 1] << 16 | SCM_BDIGITS (m)[nd - 2];
-#else
- w = SCM_BDIGITS (m)[nd - 1];
-#endif
- mask = (w < 0x10000
- ? (w < 0x100
- ? scm_masktab[w]
- : scm_masktab[w >> 8] << 8 | 0xff)
- : (w < 0x1000000
- ? scm_masktab[w >> 16] << 16 | 0xffff
- : scm_masktab[w >> 24] << 24 | 0xffffff));
- }
- b = scm_i_mkbig (nd, 0);
- bits = (LONG32 *) SCM_BDIGITS (b);
+ SCM result = scm_i_mkbig ();
+ const size_t m_bits = mpz_sizeinbase (SCM_I_BIG_MPZ (m), 2);
+ /* how many bits would only partially fill the last scm_t_uint32? */
+ const size_t end_bits = m_bits % (sizeof (scm_t_uint32) * SCM_CHAR_BIT);
+ scm_t_uint32 *random_chunks = NULL;
+ const scm_t_uint32 num_full_chunks =
+ m_bits / (sizeof (scm_t_uint32) * SCM_CHAR_BIT);
+ const scm_t_uint32 num_chunks = num_full_chunks + ((end_bits) ? 1 : 0);
+
+ /* we know the result will be this big */
+ mpz_realloc2 (SCM_I_BIG_MPZ (result), m_bits);
+
+ random_chunks =
+ (scm_t_uint32 *) scm_gc_calloc (num_chunks * sizeof (scm_t_uint32),
+ "random bignum chunks");
+
do
{
- i = nd;
- /* treat most significant digit specially */
-#if SIZEOF_INT == 4
- /* 16 bit digits */
- if (i & 1)
- {
- ((SCM_BIGDIG*) bits)[i - 1] = scm_the_rng.random_bits (state) & mask;
- i /= 2;
- }
- else
-#endif
- {
- /* fix most significant 32 bits */
-#if SIZEOF_INT == 4
- w = scm_the_rng.random_bits (state) & mask;
- ((SCM_BIGDIG*) bits)[i - 2] = w & 0xffff;
- ((SCM_BIGDIG*) bits)[i - 1] = w >> 16;
- i = i / 2 - 1;
-#else
- i /= 2;
- bits[--i] = scm_the_rng.random_bits (state) & mask;
-#endif
- }
- /* now fill up the rest of the bignum */
- while (i)
- bits[--i] = scm_the_rng.random_bits (state);
- b = scm_i_normbig (b);
- if (SCM_INUMP (b))
- return b;
- } while (scm_bigcomp (b, m) <= 0);
- return b;
+ scm_t_uint32 *current_chunk = random_chunks + (num_chunks - 1);
+ scm_t_uint32 chunks_left = num_chunks;
+
+ mpz_set_ui (SCM_I_BIG_MPZ (result), 0);
+
+ if (end_bits)
+ {
+ /* generate a mask with ones in the end_bits position, i.e. if
+ end_bits is 3, then we'd have a mask of ...0000000111 */
+ const scm_t_uint32 rndbits = state->rng->random_bits (state);
+ int rshift = (sizeof (scm_t_uint32) * SCM_CHAR_BIT) - end_bits;
+ scm_t_uint32 mask = ((scm_t_uint32)-1) >> rshift;
+ scm_t_uint32 highest_bits = rndbits & mask;
+ *current_chunk-- = highest_bits;
+ chunks_left--;
+ }
+
+ while (chunks_left)
+ {
+ /* now fill in the remaining scm_t_uint32 sized chunks */
+ *current_chunk-- = state->rng->random_bits (state);
+ chunks_left--;
+ }
+ mpz_import (SCM_I_BIG_MPZ (result),
+ num_chunks,
+ -1,
+ sizeof (scm_t_uint32),
+ 0,
+ 0,
+ random_chunks);
+ /* if result >= m, regenerate it (it is important to regenerate
+ all bits in order not to get a distorted distribution) */
+ } while (mpz_cmp (SCM_I_BIG_MPZ (result), SCM_I_BIG_MPZ (m)) >= 0);
+ scm_gc_free (random_chunks,
+ num_chunks * sizeof (scm_t_uint32),
+ "random bignum chunks");
+ return scm_i_normbig (result);
}
/*
SCM_RETURN_NEWSMOB (scm_tc16_rstate, state);
}
-static size_t
-rstate_free (SCM rstate)
-{
- free (SCM_RSTATE (rstate));
- return 0;
-}
/*
* Scheme level interface.
*/
-SCM_GLOBAL_VARIABLE_INIT (scm_var_random_state, "*random-state*", scm_seed_to_random_state (scm_makfrom0str ("URL:http://stat.fsu.edu/~geo/diehard.html")));
+SCM_GLOBAL_VARIABLE_INIT (scm_var_random_state, "*random-state*", scm_seed_to_random_state (scm_from_locale_string ("URL:http://stat.fsu.edu/~geo/diehard.html")));
SCM_DEFINE (scm_random, "random", 1, 1, 0,
(SCM n, SCM state),
if (SCM_UNBNDP (state))
state = SCM_VARIABLE_REF (scm_var_random_state);
SCM_VALIDATE_RSTATE (2, state);
- if (SCM_INUMP (n))
+ if (SCM_I_INUMP (n))
{
- unsigned long m = SCM_INUM (n);
- SCM_ASSERT_RANGE (1, n, m > 0);
- return SCM_MAKINUM (scm_c_random (SCM_RSTATE (state), m));
+ scm_t_bits m = (scm_t_bits) SCM_I_INUM (n);
+ SCM_ASSERT_RANGE (1, n, SCM_I_INUM (n) > 0);
+#if SCM_SIZEOF_UINTPTR_T <= 4
+ return scm_from_uint32 (scm_c_random (SCM_RSTATE (state),
+ (scm_t_uint32) m));
+#elif SCM_SIZEOF_UINTPTR_T <= 8
+ return scm_from_uint64 (scm_c_random64 (SCM_RSTATE (state),
+ (scm_t_uint64) m));
+#else
+#error "Cannot deal with this platform's scm_t_bits size"
+#endif
}
SCM_VALIDATE_NIM (1, n);
if (SCM_REALP (n))
- return scm_make_real (SCM_REAL_VALUE (n)
- * scm_c_uniform01 (SCM_RSTATE (state)));
- SCM_VALIDATE_SMOB (1, n, big);
+ return scm_from_double (SCM_REAL_VALUE (n)
+ * scm_c_uniform01 (SCM_RSTATE (state)));
+
+ if (!SCM_BIGP (n))
+ SCM_WRONG_TYPE_ARG (1, n);
return scm_c_random_bignum (SCM_RSTATE (state), n);
}
#undef FUNC_NAME
if (SCM_UNBNDP (state))
state = SCM_VARIABLE_REF (scm_var_random_state);
SCM_VALIDATE_RSTATE (1, state);
- return make_rstate (scm_the_rng.copy_rstate (SCM_RSTATE (state)));
+ return make_rstate (SCM_RSTATE (state)->rng->copy_rstate (SCM_RSTATE (state)));
}
#undef FUNC_NAME
"Return a new random state using @var{seed}.")
#define FUNC_NAME s_scm_seed_to_random_state
{
+ SCM res;
if (SCM_NUMBERP (seed))
seed = scm_number_to_string (seed, SCM_UNDEFINED);
SCM_VALIDATE_STRING (1, seed);
- return make_rstate (scm_c_make_rstate (SCM_STRING_CHARS (seed),
- SCM_STRING_LENGTH (seed)));
+ res = make_rstate (scm_c_make_rstate (scm_i_string_chars (seed),
+ scm_i_string_length (seed)));
+ scm_remember_upto_here_1 (seed);
+ return res;
+
+}
+#undef FUNC_NAME
+
+SCM_DEFINE (scm_datum_to_random_state, "datum->random-state", 1, 0, 0,
+ (SCM datum),
+ "Return a new random state using @var{datum}, which should have\n"
+ "been obtained from @code{random-state->datum}.")
+#define FUNC_NAME s_scm_datum_to_random_state
+{
+ return make_rstate (scm_c_rstate_from_datum (datum));
+}
+#undef FUNC_NAME
+
+SCM_DEFINE (scm_random_state_to_datum, "random-state->datum", 1, 0, 0,
+ (SCM state),
+ "Return a datum representation of @var{state} that may be\n"
+ "written out and read back with the Scheme reader.")
+#define FUNC_NAME s_scm_random_state_to_datum
+{
+ SCM_VALIDATE_RSTATE (1, state);
+ return SCM_RSTATE (state)->rng->to_datum (SCM_RSTATE (state));
}
#undef FUNC_NAME
if (SCM_UNBNDP (state))
state = SCM_VARIABLE_REF (scm_var_random_state);
SCM_VALIDATE_RSTATE (1, state);
- return scm_make_real (scm_c_uniform01 (SCM_RSTATE (state)));
+ return scm_from_double (scm_c_uniform01 (SCM_RSTATE (state)));
}
#undef FUNC_NAME
if (SCM_UNBNDP (state))
state = SCM_VARIABLE_REF (scm_var_random_state);
SCM_VALIDATE_RSTATE (1, state);
- return scm_make_real (scm_c_normal01 (SCM_RSTATE (state)));
+ return scm_from_double (scm_c_normal01 (SCM_RSTATE (state)));
}
#undef FUNC_NAME
-#ifdef HAVE_ARRAYS
-
static void
-vector_scale (SCM v, double c)
+vector_scale_x (SCM v, double c)
{
- int n = SCM_INUM (scm_uniform_vector_length (v));
- if (SCM_VECTORP (v))
- while (--n >= 0)
- SCM_REAL_VALUE (SCM_VELTS (v)[n]) *= c;
+ size_t n;
+ if (scm_is_simple_vector (v))
+ {
+ n = SCM_SIMPLE_VECTOR_LENGTH (v);
+ while (n-- > 0)
+ SCM_REAL_VALUE (SCM_SIMPLE_VECTOR_REF (v, n)) *= c;
+ }
else
- while (--n >= 0)
- ((double *) SCM_VELTS (v))[n] *= c;
+ {
+ /* must be a f64vector. */
+ scm_t_array_handle handle;
+ size_t i, len;
+ ssize_t inc;
+ double *elts;
+
+ elts = scm_f64vector_writable_elements (v, &handle, &len, &inc);
+
+ for (i = 0; i < len; i++, elts += inc)
+ *elts *= c;
+
+ scm_array_handle_release (&handle);
+ }
}
static double
vector_sum_squares (SCM v)
{
double x, sum = 0.0;
- int n = SCM_INUM (scm_uniform_vector_length (v));
- if (SCM_VECTORP (v))
- while (--n >= 0)
- {
- x = SCM_REAL_VALUE (SCM_VELTS (v)[n]);
- sum += x * x;
- }
+ size_t n;
+ if (scm_is_simple_vector (v))
+ {
+ n = SCM_SIMPLE_VECTOR_LENGTH (v);
+ while (n-- > 0)
+ {
+ x = SCM_REAL_VALUE (SCM_SIMPLE_VECTOR_REF (v, n));
+ sum += x * x;
+ }
+ }
else
- while (--n >= 0)
- {
- x = ((double *) SCM_VELTS (v))[n];
- sum += x * x;
- }
+ {
+ /* must be a f64vector. */
+ scm_t_array_handle handle;
+ size_t i, len;
+ ssize_t inc;
+ const double *elts;
+
+ elts = scm_f64vector_elements (v, &handle, &len, &inc);
+
+ for (i = 0; i < len; i++, elts += inc)
+ {
+ x = *elts;
+ sum += x * x;
+ }
+
+ scm_array_handle_release (&handle);
+ }
return sum;
}
*/
SCM_DEFINE (scm_random_solid_sphere_x, "random:solid-sphere!", 1, 1, 0,
(SCM v, SCM state),
- "Fills vect with inexact real random numbers\n"
- "the sum of whose squares is less than 1.0.\n"
- "Thinking of vect as coordinates in space of\n"
- "dimension n = (vector-length vect), the coordinates\n"
- "are uniformly distributed within the unit n-sphere.\n"
- "The sum of the squares of the numbers is returned.")
+ "Fills @var{vect} with inexact real random numbers the sum of\n"
+ "whose squares is less than 1.0. Thinking of @var{vect} as\n"
+ "coordinates in space of dimension @var{n} @math{=}\n"
+ "@code{(vector-length @var{vect})}, the coordinates are\n"
+ "uniformly distributed within the unit @var{n}-sphere.")
#define FUNC_NAME s_scm_random_solid_sphere_x
{
- SCM_VALIDATE_VECTOR_OR_DVECTOR (1, v);
if (SCM_UNBNDP (state))
state = SCM_VARIABLE_REF (scm_var_random_state);
SCM_VALIDATE_RSTATE (2, state);
scm_random_normal_vector_x (v, state);
- vector_scale (v,
- pow (scm_c_uniform01 (SCM_RSTATE (state)),
- 1.0 / SCM_INUM (scm_uniform_vector_length (v)))
- / sqrt (vector_sum_squares (v)));
+ vector_scale_x (v,
+ pow (scm_c_uniform01 (SCM_RSTATE (state)),
+ 1.0 / scm_c_generalized_vector_length (v))
+ / sqrt (vector_sum_squares (v)));
return SCM_UNSPECIFIED;
}
#undef FUNC_NAME
"unit n-sphere.")
#define FUNC_NAME s_scm_random_hollow_sphere_x
{
- SCM_VALIDATE_VECTOR_OR_DVECTOR (1, v);
if (SCM_UNBNDP (state))
state = SCM_VARIABLE_REF (scm_var_random_state);
SCM_VALIDATE_RSTATE (2, state);
scm_random_normal_vector_x (v, state);
- vector_scale (v, 1 / sqrt (vector_sum_squares (v)));
+ vector_scale_x (v, 1 / sqrt (vector_sum_squares (v)));
return SCM_UNSPECIFIED;
}
#undef FUNC_NAME
"(i.e., with mean 0 and variance 1).")
#define FUNC_NAME s_scm_random_normal_vector_x
{
- int n;
- SCM_VALIDATE_VECTOR_OR_DVECTOR (1, v);
+ long i;
+ scm_t_array_handle handle;
+ scm_t_array_dim *dim;
+
if (SCM_UNBNDP (state))
state = SCM_VARIABLE_REF (scm_var_random_state);
SCM_VALIDATE_RSTATE (2, state);
- n = SCM_INUM (scm_uniform_vector_length (v));
- if (SCM_VECTORP (v))
- while (--n >= 0)
- SCM_VECTOR_SET (v, n, scm_make_real (scm_c_normal01 (SCM_RSTATE (state))));
+
+ scm_generalized_vector_get_handle (v, &handle);
+ dim = scm_array_handle_dims (&handle);
+
+ if (scm_is_vector (v))
+ {
+ SCM *elts = scm_array_handle_writable_elements (&handle);
+ for (i = dim->lbnd; i <= dim->ubnd; i++, elts += dim->inc)
+ *elts = scm_from_double (scm_c_normal01 (SCM_RSTATE (state)));
+ }
else
- while (--n >= 0)
- ((double *) SCM_VELTS (v))[n] = scm_c_normal01 (SCM_RSTATE (state));
+ {
+ /* must be a f64vector. */
+ double *elts = scm_array_handle_f64_writable_elements (&handle);
+ for (i = dim->lbnd; i <= dim->ubnd; i++, elts += dim->inc)
+ *elts = scm_c_normal01 (SCM_RSTATE (state));
+ }
+
+ scm_array_handle_release (&handle);
+
return SCM_UNSPECIFIED;
}
#undef FUNC_NAME
-#endif /* HAVE_ARRAYS */
-
SCM_DEFINE (scm_random_exp, "random:exp", 0, 1, 0,
(SCM state),
"Return an inexact real in an exponential distribution with mean\n"
if (SCM_UNBNDP (state))
state = SCM_VARIABLE_REF (scm_var_random_state);
SCM_VALIDATE_RSTATE (1, state);
- return scm_make_real (scm_c_exp1 (SCM_RSTATE (state)));
+ return scm_from_double (scm_c_exp1 (SCM_RSTATE (state)));
+}
+#undef FUNC_NAME
+
+/* Return a new random-state seeded from the time, date, process ID, an
+ address from a freshly allocated heap cell, an address from the local
+ stack frame, and a high-resolution timer if available. This is only
+ to be used as a last resort, when no better source of entropy is
+ available. */
+static SCM
+random_state_of_last_resort (void)
+{
+ SCM state;
+ SCM time_of_day = scm_gettimeofday ();
+ SCM sources = scm_list_n
+ (scm_from_unsigned_integer (SCM_UNPACK (time_of_day)), /* heap addr */
+ scm_getpid (), /* process ID */
+ scm_get_internal_real_time (), /* high-resolution process timer */
+ scm_from_unsigned_integer ((scm_t_bits) &time_of_day), /* stack addr */
+ scm_car (time_of_day), /* seconds since midnight 1970-01-01 UTC */
+ scm_cdr (time_of_day), /* microsecond component of the above clock */
+ SCM_UNDEFINED);
+
+ /* Concatenate the sources bitwise to form the seed */
+ SCM seed = SCM_INUM0;
+ while (scm_is_pair (sources))
+ {
+ seed = scm_logxor (seed, scm_ash (scm_car (sources),
+ scm_integer_length (seed)));
+ sources = scm_cdr (sources);
+ }
+
+ /* FIXME The following code belongs in `scm_seed_to_random_state',
+ and here we should simply do:
+
+ return scm_seed_to_random_state (seed);
+
+ Unfortunately, `scm_seed_to_random_state' only preserves around 32
+ bits of entropy from the provided seed. I don't know if it's okay
+ to fix that in 2.0, so for now we have this workaround. */
+ {
+ int i, len;
+ unsigned char *buf;
+ len = scm_to_int (scm_ceiling_quotient (scm_integer_length (seed),
+ SCM_I_MAKINUM (8)));
+ buf = (unsigned char *) malloc (len);
+ for (i = len-1; i >= 0; --i)
+ {
+ buf[i] = scm_to_int (scm_logand (seed, SCM_I_MAKINUM (255)));
+ seed = scm_ash (seed, SCM_I_MAKINUM (-8));
+ }
+ state = make_rstate (scm_c_make_rstate ((char *) buf, len));
+ free (buf);
+ }
+ return state;
+}
+
+/* Attempt to fill buffer with random bytes from /dev/urandom.
+ Return 1 if successful, else return 0. */
+static int
+read_dev_urandom (unsigned char *buf, size_t len)
+{
+ size_t res = 0;
+ FILE *f = fopen ("/dev/urandom", "r");
+ if (f)
+ {
+ res = fread(buf, 1, len, f);
+ fclose (f);
+ }
+ return (res == len);
+}
+
+/* Fill a buffer with random bytes seeded from a platform-specific
+ source of entropy. /dev/urandom is used if available. Note that
+ this function provides no guarantees about the amount of entropy
+ present in the returned bytes. */
+void
+scm_i_random_bytes_from_platform (unsigned char *buf, size_t len)
+{
+ if (read_dev_urandom (buf, len))
+ return;
+ else /* FIXME: support other platform sources */
+ {
+ /* When all else fails, use this (rather weak) fallback */
+ SCM random_state = random_state_of_last_resort ();
+ int i;
+ for (i = len-1; i >= 0; --i)
+ buf[i] = scm_to_int (scm_random (SCM_I_MAKINUM (256), random_state));
+ }
+}
+
+SCM_DEFINE (scm_random_state_from_platform, "random-state-from-platform", 0, 0, 0,
+ (void),
+ "Construct a new random state seeded from a platform-specific\n\
+source of entropy, appropriate for use in non-security-critical applications.")
+#define FUNC_NAME s_scm_random_state_from_platform
+{
+ unsigned char buf[32];
+ if (read_dev_urandom (buf, sizeof(buf)))
+ return make_rstate (scm_c_make_rstate ((char *) buf, sizeof(buf)));
+ else
+ return random_state_of_last_resort ();
}
#undef FUNC_NAME
scm_t_rng rng =
{
sizeof (scm_t_i_rstate),
- (unsigned long (*)()) scm_i_uniform32,
- (void (*)()) scm_i_init_rstate,
- (scm_t_rstate *(*)()) scm_i_copy_rstate
+ scm_i_uniform32,
+ scm_i_init_rstate,
+ scm_i_copy_rstate,
+ scm_i_rstate_from_datum,
+ scm_i_rstate_to_datum
};
scm_the_rng = rng;
scm_tc16_rstate = scm_make_smob_type ("random-state", 0);
- scm_set_smob_free (scm_tc16_rstate, rstate_free);
for (m = 1; m <= 0x100; m <<= 1)
for (i = m >> 1; i < m; ++i)
#include "libguile/random.x"
- /* Check that the assumptions about bits per bignum digit are correct. */
-#if SIZEOF_INT == 4
- m = 16;
-#else
- m = 32;
-#endif
- if (m != SCM_BITSPERDIG)
- {
- fprintf (stderr, "Internal inconsistency: Confused about bignum digit size in random.c\n");
- exit (1);
- }
-
scm_add_feature ("random");
}
HCoop / bpt / guile.git / blobdiff