Re: Recursion on a list

*To*: mathgroup at smc.vnet.net*Subject*: [mg28908] Re: Recursion on a list*From*: "Stephen P Luttrell" <luttrell at signal.dra.hmg.gb>*Date*: Fri, 18 May 2001 01:13:10 -0400 (EDT)*References*: <9e02kg$305@smc.vnet.net>*Sender*: owner-wri-mathgroup at wolfram.com

"msc" <mscmsc at mediaone.net> wrote in message news:9e02kg$305 at smc.vnet.net... > Greetings, > > I'm looking for an efficient method (i.e., with the use of an explicit loop) > for the following problem. I am working with large lists (several thousand > elements) of data. Denote one such list r. I would like to define a new list > x such that: > > > x[0] = 1.0 > > x[t] = x[t-1]*(1.0 + r[t]) > > Can anyone suggest an efficient way? This does what you want: FoldList[#1(1+#2)&,1,r] where r is the list of r-values, which would have been {r[1],r[2],r[3],..} in your notation. -- Stephen P Luttrell DERA, Malvern, U.K. luttrell at signal.dera.gov.uk