Re: an easy one?
- To: mathgroup at smc.vnet.net
- Subject: [mg88897] Re: an easy one?
- From: dh <dh at metrohm.ch>
- Date: Tue, 20 May 2008 06:54:14 -0400 (EDT)
- References: <g0tr2f$mn5$1@smc.vnet.net>
Hi Francisco,
as you do not give an explicite example, I make one up: calculation of
Sqrt[2] using Newtons method: xnew= xold+ f[xold]/f'[xold] starting with
1.. Where f[x]= x^2-2 and we want an error <10^-6:
NestWhileList[#+(2-#^2)/(2#)&,1.,Abs[#^2-2]>10^-6&]
hope this helps, Daniel
Francisco Gutierrez wrote:
> I have a code (for clustering) that works well with FixedPointList.
> It takes the following form:
> FixedPointList[veamos[dataset,#]&, prototipos,10]
>
> where veamos is a function that acts on the dataset and prototipos,
> and prototipos is also a list of lists (for example {{5,5},{10,10}} )
>
> But of course using FixedPointList is imperfect. I want to use NestWhileList instead, with a criterion of termination acting on prototipos (i.e., if the absolute value of the substraction of the penultimate prototipos and the last prototipos is less than a certain amount, say 0.01, then stop).
>
> But I haven´t been able.
> Can somebody help me?
> Thanks
> Francisco Gutiérrez
>
--
Daniel Huber
Metrohm Ltd.
Oberdorfstr. 68
CH-9100 Herisau
Tel. +41 71 353 8585, Fax +41 71 353 8907
E-Mail:<mailto:dh at metrohm.com>
Internet:<http://www.metrohm.com>
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