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>

**Follow-Ups**:**Re: Re: an easy one?***From:*Murray Eisenberg <murray@math.umass.edu>