fortran & random_seed

       program test_seed

       implicit none

       real x

       integer jj

       call init_random_seed()

       do jj=1,10

       call random_number(x)  ! initial 之後 再call 即為 random ~~@@

       write(*,*) x

       enddo

       end program

       subroutine init_random_seed()

       INTEGER :: i, n, clock

       INTEGER,  ALLOCATABLE :: seed(:)

       CALL RANDOM_SEED(size = n)

       ALLOCATE(seed(n))

       CALL SYSTEM_CLOCK(COUNT=clock)

       seed = clock - 2047 * (/ (i - 1, i = 1, n) /)

       seed = seed * 1103515245 + 2531011

       CALL RANDOM_SEED(PUT = seed)

       DEALLOCATE(seed)

       end subroutine

----------------------------------------

program random_test

implicit none

  real*8 :: x(10)

!  call random_seed()

 call init_random_seed() !<- this line is for GFortran

  call random_number(x)

  write(*,'(F21.18)') x

end program