[Jprogramming] Truncating

[Roger Hui]

The point is not the number of characters but a
pattern that is useful in other areas.  In this case
the pattern is duality.  For other examples of 
duality, please see:
http://www.jsoftware.com/jwiki/Essays/Under



----- Original Message -----
From: Geoff Canyon <geoffc at inspiredlogic.com>
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 <geoffc at inspiredlogic.com> wrote:
> >> based on a calculation? For example, suppose I want to generate all
> >> the primes < 10,000.
> >
> >   i.&.(p:^:_1)10000