Re: how many times nestwhile repeats calculations?

*To*: mathgroup at smc.vnet.net*Subject*: [mg71964] Re: how many times nestwhile repeats calculations?*From*: "dimitris" <dimmechan at yahoo.com>*Date*: Wed, 6 Dec 2006 06:03:47 -0500 (EST)*References*: <el3k8b$r61$1@smc.vnet.net>

Use NestWhileList FrontEndExecute[{HelpBrowserLookup["MainBook","NestWhileList"]}] or http://documents.wolfram.com/mathematica/functions/NestWhileList Also there is relevant material in Alan Hayes's How and Why column. You can download it here: http://library.wolfram.com/infocenter/Articles/3162/ Regards Dimitris Arkadiusz.Majka at gmail.com wrote: > Hi, > > >From Help Browser we read > > NestWhile[f, expr, test] starts with expr, then repeatedly applies f > until applying test to the result no longer yields True. > > I would like to know how many times f is applied till test stops > everything. I read already a post in which the following example was > presented > > 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} > > > Do you know any other method? I don't want to influence to NestWhile > (by inserting a "counting" element #[[1]]+1 ) > > Thanks, > > Arek