Retrieves the current table used in the 32-bit Mersenne Twister generator.

Synopsis

#include <imsls.h>

void imsls_random_MT32_table_get (unsigned int **table, ..., 0)

Required Arguments

unsigned int **table (Output)
Address of a pointer to an array of length 625 containing the table used in the 32-bit Mersenne Twister generator. Typically,
unsigned int *table is declared and &table is used as an argument.

Synopsis with Optional Arguments

#include <imsls.h>

void imsls_random_MT32_table_get (int **table,
IMSLS_RETURN_USER, int r[],
0)

Optional Arguments

IMSLS_RETURN_USER, int r[] (Output)
User-supplied array of length 625 containing the table used in the 32-bit Mersenne Twister generator.

Description

The values in table contain the state of the 32-bit Mersenne Twister random number generator. The table can be used by imsls_random_MT32_table_set to set the generator back to this state.

Example

In this example, four simulation streams are generated. The first series is generated with the seed used for initialization. The second series is generated using an array for initialization. The third series is obtained by resetting the generator back to the state it had at the beginning of the second stream. Therefore, the second and third streams are identical. The fourth stream is obtained by resetting the generator back to its original, uninitialized state, and having it reinitialize using the seed. The fourth and first streams are therefore the same.

 

#include <imsls.h>

 

int main()

{

       const unsigned int init[] = {0x123, 0x234, 0x345, 0x456};

       float   *r;

       int     iseed = 123457;

       int     *itable;

       int     nr = 5;

 

       /* Initialize Mersenne Twister series with a seed */

       imsls_random_option (8);

       imsls_random_seed_set (iseed);

       r = imsls_f_random_uniform (nr, 0);

       imsls_f_write_matrix ("First stream output", 1, 5, r,

              IMSLS_NO_COL_LABELS,

              IMSLS_NO_ROW_LABELS,

              0);

       free(r);

 

       /* Reinitialize Mersenne Twister series with an array */

       imsls_random_option (8);

       imsls_random_MT32_init(4, init);

       /* Save the state of the series */

        imsls_random_MT32_table_get(&itable, 0);

 

       r = imsls_f_random_uniform (nr, 0);

       imsls_f_write_matrix ("Second stream output", 1, 5, r,

              IMSLS_NO_COL_LABELS,

              IMSLS_NO_ROW_LABELS,

              0);

       free(r);

 

       /* Restore the state of the series */

       imsls_random_MT32_table_set(itable);

 

       r = imsls_f_random_uniform (nr, 0);

       imsls_f_write_matrix ("Third stream output", 1, 5, r,

              IMSLS_NO_COL_LABELS,

              IMSLS_NO_ROW_LABELS,

              0);

       free(r);

 

       /* Reset the series - it will reinitialize from the seed */

       itable[0] = 1000;

       imsls_random_MT32_table_set(itable);

 

       r = imsls_f_random_uniform (nr, 0);

       imsls_f_write_matrix ("Fourth stream output", 1, 5, r,

              IMSLS_NO_COL_LABELS,

              IMSLS_NO_ROW_LABELS,

              0);

       free(r);

}

 

Output

                     First stream output

    0.4347       0.3522       0.0139       0.2091       0.4956

 

                    Second stream output

    0.2486       0.2226       0.1111       0.9563       0.9846

 

                     Third stream output

    0.2486       0.2226       0.1111       0.9563       0.9846

 

                    Fourth stream output

    0.4347       0.3522       0.0139       0.2091       0.4956

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