On Wed, Sep 21, 2011 at 10:12:39AM -0400, Andy Choens wrote: > If I set a set to a consitent value, say 123, and create a sample in PSPP > will it match the sample created by SPSS?
I doubt it, but can't be sure becaus the source code to SPSS is kept secret. > If someone > knows which pseudo number generator is being used by PSPP and SPSS > respectively that would also be a big help so I could > replicate / confirm output indpenedently. As of about 10 years ago, most of SPSS used a multiplicative congruential random number generator. It had a period of either 2^31 - 1 or 2^32 - 1. They may still use such a generator, since changing it would cause users' old syntax to give different answers. PSPP uses the Mersenne Twister, which has a period of 2^19937 - 1, as implemented in GSL. You can see the code for it in src/math/random.c. -Jason _______________________________________________ Pspp-users mailing list Pspp-users@gnu.org https://lists.gnu.org/mailman/listinfo/pspp-users
