Re: The most efficient Fibonacci algorithim?

*To*: mathgroup at smc.vnet.net*Subject*: [mg23405] Re: The most efficient Fibonacci algorithim?*From*: "Peter Tolksdorf" <Peter.Tolksdorf at gmx.de>*Date*: Sat, 6 May 2000 19:14:14 -0400 (EDT)*References*: <8er92l$hdq@smc.vnet.net>*Sender*: owner-wri-mathgroup at wolfram.com

Try http://www.freenet.de/Tolksdorf <zeno at magicnet.net> schrieb in im Newsbeitrag: 8er92l$hdq at smc.vnet.net... > On page 128 of the book "The Mathematica Programmer" by Roman Maeder (the > Mathematic 2.2 edition) is this Mathematica program to compute Fibonacci > numbers... > > fibj[n_]:= > Module[{r11=1,r12=0,r22=1,digits=IntegerDigits[n-1,2],i,t}, > Do[If[digits[[i]]==1, > {r11,r22}={r11(r11+2r12),r12(r11+r22)}; > r12=r11-r22, > t=r12(r11+r22); > {r11,r12}={r11(r11+2r12)-t,t}; > r22=r11-r12], > {i,Length[digits]-1}]; > If[digits[[-1]]==1, > r11(r11+2r12), > r11(r11+r22)-(-1)^((n-1)/2)]] > > The book says this is the most efficient one of a few mentioned in the book. > Does anyone know of any other programs that are faster? This one really > screams...I am curious if anyone has done anything even better. >