topic Re: Random number issue in Statistical Procedures

Random number issue

DCL — Thu, 08 Jun 2017 06:12:46 GMT

Hi,

Ever since I migrated to a new SAS server, i notice that random number generation for a seed value [334766080] gets different in this new server.

Code

data A(drop=i);

call streaminit(334766080);

do i = 1 to 5;

x123 = rand("uniform"); output;

end;

run;

Results In OLD server

x123

0.7852188905
0.1264403092
0.5529167121
0.8073481501
0.3563103683

Results in NEW Server

x123

0.9406947785
0.9712292252
0.0413521428
0.5594002416
0.1823783112

Seed value is exactly the same. Is there something else which affects the random number generation process?

Thanks in advance!

Dilip

Kurt_Bremser — Thu, 08 Jun 2017 06:37:37 GMT

What is the difference between your "OLD" and "NEW" server?

A test with SAS 9.4 TS1M2 on AIX gave me your "OLD" results; a test with 9.2 on the same platform also.

DCL — Thu, 08 Jun 2017 06:54:15 GMT

Hi Kurt,

Sorry- i forgot to mention that.

OLD server= SAS9.3

New Server= 9.4 (TS1M3 MBCS3170)

Thanks,
Dilip

DCL — Thu, 08 Jun 2017 07:49:55 GMT

It seems that there is a change in random number generation from SAS/STAT14.1

When I added following option, I get old results 🙂

OPTIONS SET=SAS_RNG_METHOD=MT1998;

Thanks,
Dilip

Kurt_Bremser — Thu, 08 Jun 2017 08:05:48 GMT

Since it does seem to affect not only certain SAS/STAT procedures, but the random function in Base SAS, this is good to know.

It also explains why I got the "old" numbers. Our SAS/STAT is at 13.2.