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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