Users might occasionally see notes in the SAS log about random number generation changes in the BCHOICE, GENMOD, MCMC, MULTTEST, NLIN, PHREG, SURVEYIMPUTE, and SURVEYSELECT procedures. For a very small number of seeds, the Mersenne twister algorithm that is used is changed as discussed in Matsumoto and Nishimura (2002). To revert to the former (1998) version of the Mersenne twister algorithm, submit the following statement:
OPTIONS SET=SAS_RNG_METHOD=MT1998;
Note that in the case of the SURVEYSELECT procedure, this message might be printed as a result of an internal stratum seed, not the initial seed that the user specifies. See SAS Language Reference: Dictionary for a description of the OPTIONS statement.