random number generator vsrnggaussian used in subroutine

[fymaterials]

Hi, guys:
I want to create a random number with Gaussian distribution probability by function vsrnggaussian.

The subroutine is:
INCLUDE '/home/fengy/mkl/10.0.3.020/include/mkl_vsl.fi'
INCLUDE '/home/fengy/mkl/10.0.3.020/examples/vslf/source/errcheck.inc'



SUBROUTINE test_sub1
USE MKL_VSL_TYPE
USE MKL_VSL

IMPLICIT NONE

REAL, DIMENSION(1) :: r

INTEGER(KIND=4) i, nn
INTEGER n
INTEGER(KIND=4) errcode

INTEGER brng, method, seed

TYPE(VSL_STREAM_STATE) :: stream
REAL a, sigma



n=1
brng = VSL_BRNG_MCG31
method = 0
seed = 777
a = 0.0
sigma = 1.0

errcode = vslnewstream(stream, brng, seed)
CALL CheckVslError(errcode)


errcode = vsrnggaussian(method, stream, n, r, a, sigma)
CALL CheckVslError(errcode)

WRITE(*,*) 'now r is: ', r(1)






END SUBROUTINE test_sub1

The main program is:
PROGRAM test_g_r


IMPLICIT NONE


INTEGER n

REAL, DIMENSION(1) :: r





DO n=1, 10
CALL test_sub1
ENDDO



END PROGRAM test_g_r

However, the output of r(1) does not change. It is a intrinsic problem for function vsrnggaussian? What can I do so that each time test_sub1 is called, it will give a random number which has Gaussian distribution density?

Thanks!
Arthur

[Andrey_N_Intel]

Your program creates and initializes random stream with the same basic random generator and seed 10 times in subroutine test_sub1. So, output of the Gaussian generator is not changed. Can you create/initialize random stream once in your main program andpass the stream in the subroutine test_sub1? Please, do not forget to remove initialization of the stream in the sub-routine.Also, please free resources allocated for random stream in the main programwhengeneration of random numbers is completed.Routine vsldeletestream can be used for this purpose. Thanks, Andrey