glib/tests/rand-test.c
George Lebl 80591652ff Add the init_by_array functionality from the reference implementation of
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.
2004-01-10 01:38:55 +00:00

136 lines
2.8 KiB
C

#undef G_DISABLE_ASSERT
#undef G_LOG_DOMAIN
#include <glib.h>
/* Outputs tested against the reference implementation mt19937ar.c from
http://www.math.keio.ac.jp/~matumoto/MT2002/emt19937ar.html */
/* Tests for a simple seed, first number is the seed */
const guint32 first_numbers[] =
{
0x7a7a7a7a,
0xfdcc2d54,
0x3a279ceb,
0xc4d39c33,
0xf31895cd,
0x46ca0afc,
0x3f5484ff,
0x54bc9557,
0xed2c24b1,
0x84062503,
0x8f6404b3,
0x599a94b3,
0xe46d03d5,
0x310beb78,
0x7bee5d08,
0x760d09be,
0x59b6e163,
0xbf6d16ec,
0xcca5fb54,
0x5de7259b,
0x1696330c,
};
/* array seed */
const guint32 seed_array[] =
{
0x6553375f,
0xd6b8d43b,
0xa1e7667f,
0x2b10117c
};
/* tests for the array seed */
const guint32 array_outputs[] =
{
0xc22b7dc3,
0xfdecb8ae,
0xb4af0738,
0x516bc6e1,
0x7e372e91,
0x2d38ff80,
0x6096494a,
0xd162d5a8,
0x3c0aaa0d,
0x10e736ae
};
const gint length = sizeof (first_numbers) / sizeof (first_numbers[0]);
const gint seed_length = sizeof (seed_array) / sizeof (seed_array[0]);
const gint array_length = sizeof (array_outputs) / sizeof (array_outputs[0]);
int main()
{
guint n;
guint ones;
double proportion;
GRand* rand = g_rand_new_with_seed (first_numbers[0]);
GRand* copy;
for (n = 1; n < length; n++)
g_assert (first_numbers[n] == g_rand_int (rand));
g_rand_set_seed (rand, 2);
g_rand_set_seed_array (rand, seed_array, seed_length);
for (n = 0; n < array_length; n++)
g_assert (array_outputs[n] == g_rand_int (rand));
copy = g_rand_copy (rand);
for (n = 0; n < 100; n++)
g_assert (g_rand_int (copy) == g_rand_int (rand));
for (n = 1; n < 100000; n++)
{
gint32 i;
gdouble d;
gboolean b;
i = g_rand_int_range (rand, 8,16);
g_assert (i >= 8 && i < 16);
i = g_random_int_range (8,16);
g_assert (i >= 8 && i < 16);
d = g_rand_double (rand);
g_assert (d >= 0 && d < 1);
d = g_random_double ();
g_assert (d >= 0 && d < 1);
d = g_rand_double_range (rand, -8, 32);
g_assert (d >= -8 && d < 32);
d = g_random_double_range (-8, 32);
g_assert (d >= -8 && d < 32);
b = g_random_boolean ();
g_assert (b == TRUE || b == FALSE);
b = g_rand_boolean (rand);
g_assert (b == TRUE || b == FALSE);
}
/* Statistical sanity check, count the number of ones
* when getting random numbers in range [0,3) and see
* that it must be semi-close to 0.25 with a VERY large
* probability */
ones = 0;
for (n = 1; n < 100000; n++)
{
if (g_random_int_range (0, 4) == 1)
ones ++;
}
proportion = (double)ones / (double)100000;
/* 0.025 is overkill, but should suffice to test for some unreasonability */
g_assert (ABS (proportion - 0.25) < 0.025);
g_rand_free (rand);
g_rand_free (copy);
return 0;
}