See also: http://www.jsoftware.com/jwiki/Essays/Primes_Less_Than_n
----- Original Message ----- From: Geoff Canyon <[EMAIL PROTECTED]> Date: Sunday, March 4, 2007 10:04 pm Subject: Re: [Jprogramming] Truncating > Wow -- that's great stuff. I tried it, and it worked a treat. If I > > understand correctly, the &. command joins the i. and the > (p:^:_1), > which is the inverse of p:. So this command says: apply the > inverse > of the prime function to 10000 to find what the order of that > prime > is, then iterate up to that number, then get the primes up to that > > index. I'm curious -- how is the use of &. better than just > writing > out what is needed. As far as I can see these are equivalent: > > i.&.(p:^:_1)10000 > p:i.(p:^:_1)10000 > > They take the same number of characters to type, so why is the > former > preferred to the latter? > > regards, > > Geoff > > On Mar 4, 2007, at 12:42 AM, Raul Miller wrote: > > > On 3/4/07, Geoff Canyon <[EMAIL PROTECTED]> wrote: > >> based on a calculation? For example, suppose I want to generate all > >> the primes < 10,000. > > > > i.&.(p:^:_1)10000 ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
