On Sun, Jun 8, 2008 at 6:42 PM, Steinar H. Gunderson <[EMAIL PROTECTED]> wrote: > On Sun, Jun 08, 2008 at 04:24:43PM -0400, Antonio Cangiano wrote: > > As I said above, you may have implemented a relatively fast sieve, but > > it isn't useful at all when it comes to trying to find new Mersenne primes. > > Actually, looking at the code, I'd guess it's quite a lot slower than the > Sieve of Atkins if you implemented both in C or another similarly > machine-near language.
Yes, "may" was the keyword. As I suggested to him via email, a formal mathematical approach is required in order to compare the computational complexity of two algorithms (and of course, their correctness), as opposed to comparing the execution time of their implementations in Ruby. His enthusiasm is admirable, but as I told him, extraordinary claims demand extraordinary proof - or it's easy to be discarded merely as a 'crackpot'. :) As a matter of fact, a non-optimized version of Atkin's sieve can be slower than a naive implementation of Erathosthenes' sieve. I tried using it for primes up to a few million, and noticed that Erathosthenes' sieve was as fast, and in same instances faster, than his Atkin implementation, which further confirms that benchmarking against it doesn't provide any basic evidence of his claims nor warrants, I'm afraid, any further investigation. Cheers, Antonio -- http://antoniocangiano.com - Zen and the Art of Programming http://stacktrace.it - Aperiodico di resistenza informatica. http://math-blog.com - Math Blog: Mathematics is wonderful! _______________________________________________ Prime mailing list [email protected] http://hogranch.com/mailman/listinfo/prime
