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  • Modified a comment on discussion Open Discussion on Practically Random

    It's clear that mm32 fails statistical tests such as the binary rank test. There are theoretical results claiming Lagged Fibonacci generators with addition modulo 2 must fail the binary rank test. (See "Matrices and the Structure of Random Number Sequences" by George Marsaglia and Liang-Huei Tsay, 1985.) But these Lagged Fibonacci generators with addition modulo 2 are not mm32. The generator mm32 implemented in PractRand is actually F(24, 55, +) in Marsaglia and Tsay's notation. Knuth [section 3.2.2,...

  • Posted a comment on discussion Open Discussion on Practically Random

    It's clear that mm32 fails statistical tests such as the binary rank test. There are theoretical results claiming Lagged Fibonacci generators with addition modulo 2 must fail the binary rank test. (See "Matrices and the Structure of Random Number Sequences" by George Marsaglia and Liang-Huei Tsay, 1985.) But these Lagged Fibonacci generators with addition modulo 2 are not mm32. The generator mm32 implemented in PractRand is actually F(24, 55, +) in Marsaglia and Tsay's notation. Knuth [section 3.2.2,...

  • Modified a comment on discussion Open Discussion on Practically Random

    mm32 is short for Mitchell-Moore algorithm on 32 bit integers. Unfortunately, there are actually multiple different (largely unrelated) algorithms I've seen referred to by that name, apparently those two published a bit. It's basically a medium-large lagged sum PRNG. I think I might have gotten if from an early eddition of Knuth? Very possible as Knuth does mention it. Section 3.2.2, page 26, chapter 3, volume 2, 2nd edition. It seems that X_{n + 1} = (X_n + X_{n - k} mod m where k is "a comparatively...

  • Posted a comment on discussion Open Discussion on Practically Random

    mm32 is short for Mitchell-Moore algorithm on 32 bit integers. Unfortunately, there are actually multiple different (largely unrelated) algorithms I've seen referred to by that name, apparently those two published a bit. It's basically a medium-large lagged sum PRNG. I think I might have gotten if from an early eddition of Knuth? Very possible as Knuth does mention it. Section 3.2.2, page 26, chapter 3, volume 2, 3rd edition. It seems that X_{n + 1} = (X_n + X_{n - k} mod m where k is "a comparatively...

  • Modified a comment on discussion Open Discussion on Practically Random

    I'm about to end my search as I'm not sure I'm going to wait for an STS run of 1 or 2 gigabits. I'm running a 1 gigabit sample size now, but I don't know if this will take just 16 hours or less. Can't run it with sample size 1073741824. It core-dumps. So typical. %gdb assess core GNU gdb (Ubuntu 8.1-0ubuntu3.1) 8.1.0.20180409-git [...] Reading symbols from assess...done. [New LWP 32403] Core was generated by `./assess 1073741824'. Program terminated with signal SIGSEGV, Segmentation fault. #0 0x0000556566812514...

  • Posted a comment on discussion Open Discussion on Practically Random

    I'm about to end my search as I'm not sure I'm going to wait for an STS run of 1 or 2 gigabits. I'm running a 1 gigabit sample size now, but I don't know if this will take just 16 hours or less. Can't run that sample size. It core-dumps. So typical. %gdb assess core GNU gdb (Ubuntu 8.1-0ubuntu3.1) 8.1.0.20180409-git [...] Reading symbols from assess...done. [New LWP 32403] Core was generated by `./assess 1073741824'. Program terminated with signal SIGSEGV, Segmentation fault. #0 0x0000556566812514...

  • Posted a comment on discussion Open Discussion on Practically Random

    Good morning. Confirming your notes, mm32 seems to be a false negative by STS. https://pastebin.com/raw/xCDSrQLL (I'm considering the OverlappingTemplate as broken at this sample size.) Let's do some calculations to make sure the comparison has a minimum of fairness. STS is analysing 256 megabits for each of the 32 samples, so that's 256 * 32 * 2^20 bits which is 8 gigabits. Under the analysis of PractRand, mm2 fails at 256 megabytes which is 2 gigabits. SmallCrush consumes roughly 908004792 bytes...

  • Posted a comment on discussion Open Discussion on Practically Random

    I finally completed the STS run of ranrot32 with seed 0. Here is the results: STS on ranrot32: https://pastebin.com/raw/aMAb7w9a It also passes SmallCrush and Crush: ========= Summary results of SmallCrush ========= Version: TestU01 1.2.3 Generator: ranrot32-seed-0 Number of statistics: 15 Total CPU time: 00:00:07.38 All tests were passed ========= Summary results of Crush ========= Version: TestU01 1.2.3 Generator: reports/ranrot32-seed-0-medium.txt Number of statistics: 144 Total CPU time: 00:35:23.19...

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