Re: NestWhile iterator.
- To: mathgroup at smc.vnet.net
- Subject: [mg66534] Re: NestWhile iterator.
- From: "Ray Koopman" <koopman at sfu.ca>
- Date: Fri, 19 May 2006 03:39:37 -0400 (EDT)
- References: <e4bivp$1ap$1@smc.vnet.net>
- Sender: owner-wri-mathgroup at wolfram.com
I too remember seeing the post you're talking about but don't remember
its subject, so here's a routine that counts the Newton iterations for
a square root.
In[1]:= mysqrt[a_] := NestWhile[{#[[1]]+1, .5(#[[2]]+a/#[[2]])}&,
{0, Max[1.,N@a]}, #[[2]]^2 > a&]
In[2]:= mysqrt[2]
Out[2]= {5, 1.41421}