For example: ] xy=: _4 4 p:"0 ] 2^64x 18446744073709551557 18446744073709551629 ] x=: */ xy 340282366920938462614824380041128836353 q: x |break | q:x (No answer after 60 seconds.)
In contrast, after entering x into http://www.alpertron.com.ar/ecm.htm the answer came back instantaneously. ----- Original Message ----- From: Roger Hui <[EMAIL PROTECTED]> Date: Wednesday, February 7, 2007 9:28 am Subject: Re: [Jgeneral] speeding up J > The q: algorithm in J is not the best known. > (I am not a factoring expert.) It uses > elliptic curves together with Miller-Rabin to > test for primes. You may want to try > http://www.alpertron.com.ar/ecm.htm > > > > ----- Original Message ----- > From: Devon McCormick <[EMAIL PROTECTED]> > Date: Wednesday, February 7, 2007 9:14 am > Subject: Re: [Jgeneral] speeding up J > > ... > > Having made the case against attempting to > parallelize most J primitives on a multi-core > architecture, I am currently running something > in J which could potentially benefit from this > though I don't know the details of the Miller-Rabin > factoring algorithm (which I believe underlies q:) > sufficiently well to say this for certain: I've > been running q: on an 88-digit number for about > the past two days. Until it finishes, I'm > reluctant to shut down my machine. A potentially > long-running algorithm like this is one of the few > that might benefit from the current multi-core > trends. ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
