pm_distUnif::setUnifRandState Interface Reference

Set the state of the Fortran default random number generator (RNG) to a random value or to an optionally deterministic, optionally processor-dependent value based on the user-specified input scalar seed and processor ID. More...

Detailed Description

Set the state of the Fortran default random number generator (RNG) to a random value or to an optionally deterministic, optionally processor-dependent value based on the user-specified input scalar seed and processor ID.

The procedures of this generic interface offer a convenient interface for the following tasks:

1. When all optional arguments are missing, this generic interface (re)sets the state of the default Fortran RNG to random values.
   
2. When the optional argument seed is present and imageID is missing, this generic interface sets the RNG state vector to a deterministic value exclusively based on the input scalar seed.
   The generated state vector is set identically on all images/processes/threads that individually call this generic interface.
   
3. When both optional arguments seed and imageID are present, this generic interface sets the RNG state vector to a deterministic value unique to each process/thread/image (based on the specified input process-unique imageID).
   

Parameters

[in]	seed	: The input scalar of type integer of default kind IK, containing a positive integer that serves as the starting point to generate the full RNG state. Specify this input argument if you wish to make random simulations reproducible, even between multiple independent runs of the program compiled by the same compiler. (optional. If missing, it is set to a value determined by the current date and time.)
[in]	imageID	: The input positive scalar integer of default kind IK containing the ID of the current image/thread/process. This can be, The Coarray image ID as returned by Fortran intrinsic this_image() within a global team of Coarray images. The MPI rank of the processor (plus one) as returned by the MPI library intrinsic mpi_comm_rank(). The OpenMP thread number as returned by the OpenMP library intrinsic omp_get_thread_num(). Any (positive) integer that uniquely identifies the current processor from other processes. The image/process/thread ID can be readily obtained by calling getImageID. This number will be used to set the RNG state uniquely on each processor. (optional. If missing, the RNG state will be set identically on all images.)

Possible calling interfaces ⛓

use pm_lkind, only: IK
use pm_distUnif, only: setUnifRandState
 
call setUnifRandState(seed = seed, imageID = imageID)

Warning

The condition 0 < imageID must hold for the corresponding input arguments.

Remarks

The procedures under discussion are impure.

See also

rngf
isHead
getUnifCDF
getUnifRand
setUnifRand
getUnifRandState
setUnifRandState
rngu_type
rngf_type
splitmix64_type
xoshiro256ssw_type
getUnifRandStateSize

Example usage ⛓

program example
 
    use pm_kind, only: SK, IK, LK
    use pm_io, only: display_type
    use pm_parallelism, only: getImageID
    use pm_distUnif, only: setUnifRandState
 
    implicit none
 
    integer(IK), allocatable :: unifRandState(:)
 
    type(display_type) :: disp
 
    disp = display_type(file = "main.out.F90")
 
    call disp%skip()
    call disp%show("!%%%%%%%%%%%%%%%%%%%%%%%%%%")
    call disp%show("! Set the current RNG seed.")
    call disp%show("!%%%%%%%%%%%%%%%%%%%%%%%%%%")
    call disp%skip()
 
    call disp%skip()
    call disp%show("call setUnifRandState()")
                    call setUnifRandState()
    call disp%skip()
 
    call disp%skip()
    call disp%show("!%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%")
    call disp%show("! Set the current RNG seed based on the input scalar `seed`.")
    call disp%show("!%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%")
    call disp%skip()
 
    call disp%skip()
    call disp%show("call setUnifRandState(seed = 12345_IK)")
                    call setUnifRandState(seed = 12345_IK)
    call disp%skip()
 
    call disp%skip()
    call disp%show("!%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%")
    call disp%show("! Set the current RNG seed on each image distinctly based on the current date and time and and the image ID.")
    call disp%show("!%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%")
    call disp%skip()
 
    call disp%skip()
    call disp%show("call setUnifRandState(imageID = getImageID())")
                    call setUnifRandState(imageID = getImageID())
    call disp%skip()
 
    call disp%skip()
    call disp%show("!%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%")
    call disp%show("! Set the current RNG seed on each image distinctly based on the input scalar `seed` and and the image ID.")
    call disp%show("!%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%")
    call disp%skip()
 
    call disp%skip()
    call disp%show("call setUnifRandState(seed = 12345_IK, imageID = getImageID())")
                    call setUnifRandState(seed = 12345_IK, imageID = getImageID())
    call disp%skip()
 
end program example

Example Unix compile command via Intel ifort compiler ⛓

#!/usr/bin/env sh
rm main.exe
ifort -fpp -standard-semantics -O3 -Wl,-rpath,../../../lib -I../../../inc main.F90 ../../../lib/libparamonte* -o main.exe
./main.exe

Example Windows Batch compile command via Intel ifort compiler ⛓

del main.exe
set PATH=..\..\..\lib;%PATH%
ifort /fpp /standard-semantics /O3 /I:..\..\..\include main.F90 ..\..\..\lib\libparamonte*.lib /exe:main.exe
main.exe

Example Unix / MinGW compile command via GNU gfortran compiler ⛓

#!/usr/bin/env sh
rm main.exe
gfortran -cpp -ffree-line-length-none -O3 -Wl,-rpath,../../../lib -I../../../inc main.F90 ../../../lib/libparamonte* -o main.exe
./main.exe

Example output ⛓

 
!%%%%%%%%%%%%%%%%%%%%%%%%%%
! Set the current RNG seed.
!%%%%%%%%%%%%%%%%%%%%%%%%%%
 
 
call setUnifRandState()
 
 
!%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
! Set the current RNG seed based on the input scalar `seed`.
!%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 
 
call setUnifRandState(seed = 12345_IK)
 
 
!%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
! Set the current RNG seed on each image distinctly based on the current date and time and and the image ID.
!%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 
 
call setUnifRandState(imageID = getImageID())
 
 
!%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
! Set the current RNG seed on each image distinctly based on the input scalar `seed` and and the image ID.
!%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 
 
call setUnifRandState(seed = 12345_IK, imageID = getImageID())
 
 

Test:

test_pm_distUnif

Final Remarks ⛓

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For details on the naming abbreviations, see this page.
For details on the naming conventions, see this page.
This software is distributed under the MIT license with additional terms outlined below.

1. If you use any parts or concepts from this library to any extent, please acknowledge the usage by citing the relevant publications of the ParaMonte library.
   
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Help us justify its continued development and maintenance by acknowledging its benefit to society, distributing it, and contributing to it.

Copyright

Computational Data Science Lab

Author:

Amir Shahmoradi, September 1, 2017, 12:00 AM, Institute for Computational Engineering and Sciences (ICES), The University of Texas Austin

Definition at line 3993 of file pm_distUnif.F90.

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The documentation for this interface was generated from the following file:

• src/fortran/main/pm_distUnif.F90