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80591652ff
Fri Dec 19 11:49:21 2003 George Lebl <jirka@5z.com>
* glib/grand.c
glib/grand.h (g_rand_new) (g_rand_new_with_seed)
(g_rand_new_with_seed_array) (g_rand_set_seed_array): Add
the init_by_array functionality from the reference implementation
of the mersenne twister (mt19937ar.c) and change the naming
to fit with the rest of the grand API. New functions are
g_rand_new_with_seed_array, g_rand_set_seed_array. This is only
reliable/tested for the 2.2 version of the seeding as that's what
the reference implementation uses. Also modify g_rand_new to
get 4 longs from /dev/urandom since that will always be available
anyway and we get more entropy and if /dev/urandom is unavailable
use also 4 longs for seeding using secs, usecs, getpid and getppid.
For version 2.0 use only a simple seed again but be more careful
about seeding with secs/usecs in this case.
* glib/grand.c
glib/grand.h (g_rand_copy): Add g_rand_copy function to copy the
current state of the random number generator.
* glib/grand.c (g_rand_new): Add testing for EINTR when reading
from /dev/urandom
* tests/rand-test.c: add testing of the array seeding stuff against
the reference implementation, plus add statistical sanity check
to see that the values outputted are truly kind of random. And
check that g_rand_copy truly copies the state by checking a few
terms.
136 lines
2.8 KiB
C
136 lines
2.8 KiB
C
#undef G_DISABLE_ASSERT
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#undef G_LOG_DOMAIN
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#include <glib.h>
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/* Outputs tested against the reference implementation mt19937ar.c from
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http://www.math.keio.ac.jp/~matumoto/MT2002/emt19937ar.html */
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/* Tests for a simple seed, first number is the seed */
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const guint32 first_numbers[] =
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{
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0x7a7a7a7a,
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0xfdcc2d54,
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0x3a279ceb,
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0xc4d39c33,
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0xf31895cd,
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0x46ca0afc,
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0x3f5484ff,
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0x54bc9557,
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0xed2c24b1,
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0x84062503,
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0x8f6404b3,
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0x599a94b3,
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0xe46d03d5,
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0x310beb78,
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0x7bee5d08,
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0x760d09be,
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0x59b6e163,
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0xbf6d16ec,
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0xcca5fb54,
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0x5de7259b,
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0x1696330c,
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};
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/* array seed */
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const guint32 seed_array[] =
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{
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0x6553375f,
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0xd6b8d43b,
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0xa1e7667f,
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0x2b10117c
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};
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/* tests for the array seed */
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const guint32 array_outputs[] =
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{
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0xc22b7dc3,
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0xfdecb8ae,
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0xb4af0738,
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0x516bc6e1,
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0x7e372e91,
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0x2d38ff80,
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0x6096494a,
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0xd162d5a8,
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0x3c0aaa0d,
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0x10e736ae
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};
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const gint length = sizeof (first_numbers) / sizeof (first_numbers[0]);
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const gint seed_length = sizeof (seed_array) / sizeof (seed_array[0]);
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const gint array_length = sizeof (array_outputs) / sizeof (array_outputs[0]);
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int main()
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{
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guint n;
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guint ones;
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double proportion;
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GRand* rand = g_rand_new_with_seed (first_numbers[0]);
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GRand* copy;
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for (n = 1; n < length; n++)
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g_assert (first_numbers[n] == g_rand_int (rand));
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g_rand_set_seed (rand, 2);
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g_rand_set_seed_array (rand, seed_array, seed_length);
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for (n = 0; n < array_length; n++)
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g_assert (array_outputs[n] == g_rand_int (rand));
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copy = g_rand_copy (rand);
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for (n = 0; n < 100; n++)
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g_assert (g_rand_int (copy) == g_rand_int (rand));
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for (n = 1; n < 100000; n++)
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{
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gint32 i;
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gdouble d;
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gboolean b;
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i = g_rand_int_range (rand, 8,16);
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g_assert (i >= 8 && i < 16);
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i = g_random_int_range (8,16);
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g_assert (i >= 8 && i < 16);
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d = g_rand_double (rand);
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g_assert (d >= 0 && d < 1);
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d = g_random_double ();
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g_assert (d >= 0 && d < 1);
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d = g_rand_double_range (rand, -8, 32);
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g_assert (d >= -8 && d < 32);
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d = g_random_double_range (-8, 32);
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g_assert (d >= -8 && d < 32);
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b = g_random_boolean ();
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g_assert (b == TRUE || b == FALSE);
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b = g_rand_boolean (rand);
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g_assert (b == TRUE || b == FALSE);
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}
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/* Statistical sanity check, count the number of ones
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* when getting random numbers in range [0,3) and see
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* that it must be semi-close to 0.25 with a VERY large
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* probability */
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ones = 0;
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for (n = 1; n < 100000; n++)
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{
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if (g_random_int_range (0, 4) == 1)
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ones ++;
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}
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proportion = (double)ones / (double)100000;
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/* 0.025 is overkill, but should suffice to test for some unreasonability */
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g_assert (ABS (proportion - 0.25) < 0.025);
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g_rand_free (rand);
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g_rand_free (copy);
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return 0;
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}
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