Re: Mersenne: Any statistics majors out there?

1999-05-11 Thread Jud McCranie
At 10:13 AM 5/11/99 +, you wrote: The theoretical distribution is most definitely not an F-distribution, though the shape may be reminiscent. If we knew what the distribution is theoretically, we could fit it. I'm a former temporary part-time adjunct instructor of statistics for a minor

Re: Mersenne: Any statistics majors out there?

1999-05-10 Thread Brian J Beesley
Yesterday I wrote Could I suggest that the maximum convolution error is likely to occur when whole blocks of bits are 1, thus forcing large integers into the transform so that rounding/truncation errors are most likely to occur. Consider the LL test algorithm x' = (x^2 - 2) (mod 2^p - 1)

Re: Mersenne: Any statistics majors out there?

1999-05-10 Thread Brian J Beesley
though. So outside about 14 sigmas you should be able to say the probability is below 10e-40. The problem is that if there are small deviations from "Gaussian-ness" way out on the wings of your distribution, the REAL probability of a certain result is not well approximated by the Error

Re: Mersenne: Any statistics majors out there?

1999-05-10 Thread Nicolau C. Saldanha
On Mon, 10 May 1999, Brian J Beesley wrote: though. So outside about 14 sigmas you should be able to say the probability is below 10e-40. The problem is that if there are small deviations from "Gaussian-ness" way out on the wings of your distribution, the REAL probability of a

Re: Mersenne: Any statistics majors out there?

1999-05-10 Thread BJ . Beesley
I am sorry, but what is kurtosis? Some measure of the speed with which the tail of the distribution falls, maybe? Or some sort of curvature? Kurtosis is the excess of the fourth moment with respect to the normal distribution. A distribution with positive kurtosis has longer "tails" than a

Re: Mersenne: Any statistics majors out there?

1999-05-08 Thread Chris Nash
though. So outside about 14 sigmas you should be able to say the probability is below 10e-40. The problem is that if there are small deviations from "Gaussian-ness" way out on the wings of your distribution, the REAL probability of a certain result is not well approximated by the Error

Re: Mersenne: Any statistics majors out there?

1999-05-08 Thread Jud McCranie
At 12:00 PM 5/8/99 -0400, Chris Nash wrote: This is a real good point - if we are assuming a Gaussian distribution, then we are assuming the best case. The worst case is given by Tchebycheff's theorem, which states that, given a probability distribution where only the mean and standard deviation

Re: Mersenne: Any statistics majors out there?

1999-05-08 Thread Jud McCranie
At 06:17 PM 5/8/99 -0500, Ken Kriesel wrote: Aren't gaussians symmetric about the mean value? What George plotted is not. Yes, but isn't too far off. But it does drop off quite a bit faster onthe left. That is why I think it may be better to chop the data at the mean, throw away that under

Mersenne: Any statistics majors out there?

1999-05-07 Thread George Woltman
Hi all, I'm working on version 19 of prime95 and I need your help. In the past, the exponents at which a larger FFT is used was picked rather haphazardly. I simply picked a few exponents trying to find one that could run a thousand or so iterations without the convolution error greatly

Re: Mersenne: Any statistics majors out there?

1999-05-07 Thread Todd Sauke
George, You indicate that that the error distribution looks "like a Bell curve". There is reasonable theoretical basis for the errors to follow a Bell curve. The sum of many random plusses and minuses combine as in the classic "random walk" problem to give a Gaussian probability distribution.