mtprng_rand_real1 Function

public function mtprng_rand_real1(state) result(r)

NAME

mtprng_rand_real1(3f) - [M_random:MERSENNE TWISTER] Obtain a pseudo-random real number in the range [0.0,1.0]
(LICENSE:CUSTOM OPEN)

SYNOPSIS

function mtprng_rand_real1(state) result(r)
type(mtprng_state), intent(inout) :: state
real(IEEE64) :: r

DESCRIPTION

Obtain a pseudo-random real number in the range [0,1], i.e., a number
greater than or equal to 0 and less than or equal to 1.

OPTIONS

state  generator state initialized by mtprng_init(3f) or mtprng_init_array(3f)

RETURNS

 r      ...

EXAMPLE

Sample program:

program demo_mtprng_real1
use M_random, only : mtprng_init
use M_random, only : mtprng_state
use M_random, only : mtprng_rand_real1
use, intrinsic :: iso_fortran_env, only : int32
implicit none
integer(INT32) :: seed
type(mtprng_state) :: state
  GET_SEED: block
  integer :: count
  integer :: count_rate
     call system_clock(count, count_rate)
     seed = count
  endblock GET_SEED
  call mtprng_init(seed, state)
  write(*,*) mtprng_rand_real1(state)
end program demo_mtprng_real1

Arguments

Type IntentOptional Attributes Name
type(mtprng_state), intent(inout) :: state

Return Value real(kind=IEEE64)


Source Code

function mtprng_rand_real1(state) result(r)

! ident_13="@(#) M_random mtprng_rand_real1(3f) Obtain a pseudo-random real number .ge. 0 and .le.= 1."

! arguments
type(mtprng_state), intent(inout) :: state
! return type
real(IEEE64) :: r

   ! Local constant; precalculated to avoid division below
   real(IEEE64), parameter :: factor = 1.0_IEEE64 / 4294967295.0_IEEE64

   ! compute
   r = real(mtprng_rand64(state),IEEE64) * factor

end function mtprng_rand_real1