Re: Recursion

*To*: mathgroup at smc.vnet.net*Subject*: [mg54965] Re: Recursion*From*: dh <dh at metrohm.ch>*Date*: Tue, 8 Mar 2005 05:03:51 -0500 (EST)*References*: <d0guu7$7jn$1@smc.vnet.net>*Sender*: owner-wri-mathgroup at wolfram.com

Hello Chris, You are looking for a fix point of your function Wo. The easiest way to do this is to use the function: FixedPoint (see the help): FixedPoint[Wo,startingvalue] where Wo[x_Number] must return a number and startingvalue is a suitable numerical starting value. However, this lets you not control the accuracy (only the max. number of steps) If you want control using the accuracy, use NestWhile.g.: NestWhile[Wo, 0.1, (Abs[#1 - #2] > 10^-5) &, 2] (see help) good luck, Daniel Christopher Grinde wrote: > Hi. > I am quite new to mathematica and need help to set up a recursion loop: > > > \!\(W\_0[T_] := \@\(\(\(12\ \[CurlyEpsilon]\_Si\)\/\(q\ a\)\) \(\(2\ > \(k\_B\) \ > T\)\/q\) Log[\(a\ W\_0[T]\)\/\(2\ n\_i[T]\)]\)\%3\) > > How do I make this a recursive function which i can supply a start value for > W0 and a limit for accuracy (W0[n]-W0[n+1]< some limit) > > Any help would be highly appreciated