RNGE64

Retrieves the current table used in the 64-bit Mersenne Twister generator.

Required Arguments

MTABLE — Integer(kind=8) array of length 313 containing the table used in the 64-bit Mersenne Twister  generator. (Output)

FORTRAN 90 Interface

Generic:                              CALL RNGE64 (MTABLE)

Specific:                             The specific interface name is RNGE64

FORTRAN 77 Interface

Single:                                CALL RNGE64 (MTABLE)

Description

The values in the table contain the state of the 64-bit Mersenne Twister random number generator. The table can be used by RNSE64 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 first and fourth streams are therefore the same.

 

      USE RNIN64_INT

      USE RNGE64_INT

      USE RNSET_INT

      USE UMACH_INT

      USE RNUN_INT

      IMPLICIT   NONE

      INTEGER    I, ISEED, NOUT

      INTEGER(KIND=8) INIT(4)

      DATA INIT/291,564,837,1110/

      DATA ISEED/123457/

      INTEGER NR

      REAL R(5)

      INTEGER(KIND=8) MTABLE(313)

      CHARACTER CLABEL(5)*5, FMT*8, RLABEL(3)*5

      RLABEL(1)='NONE'

      CLABEL(1)='NONE'

      DATA FMT/'(W10.4)'/

      NR=5

      CALL UMACH (2, NOUT)

      ISEED = 123457

      CALL RNOPT(9)

      CALL RNSET(ISEED)

      CALL RNUN(R)

      CALL WRRRL('FIRST STREAM OUTPUT',1,5,R,1,0, &

                  FMT, RLABEL, CLABEL)

!     REINITIALIZE MERSENNE TWISTER SERIES WITH AN ARRAY

      CALL RNIN64(INIT)

!     SAVE THE STATE OF THE SERIES

      CALL RNGE64(MTABLE)

      CALL RNUN(R)

      CALL WRRRL('SECOND STREAM OUTPUT',1,5,R,1,0, &

                   FMT, RLABEL, CLABEL)

!     RESTORE THE STATE OF THE TABLE

      CALL RNSE64(MTABLE)

      CALL RNUN(R)

      CALL WRRRL('THIRD STREAM OUTPUT',1,5,R,1,0, &

                   FMT, RLABEL, CLABEL)

!     RESET THE SERIES - IT WILL REINITIALIZE FROM THE SEED

      MTABLE(1)=1000

      CALL RNSE64(MTABLE)

      CALL RNUN(R)

      CALL WRRRL('FOURTH STREAM OUTPUT',1,5,R,1,0, &

                   FMT, RLABEL, CLABEL)

      END

Output

 

                     First stream output

     0.5799      0.9401      0.7102      0.1640      0.5457

                    Second stream output

     0.4894      0.7397      0.5725      0.0863      0.7588

                     Third stream output

     0.4894      0.7397      0.5725      0.0863      0.7588

                    Fourth stream output

     0.5799      0.9401      0.7102      0.1640      0.5457


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