Re: Creating List of Sequence Iterates
- To: mathgroup at smc.vnet.net
- Subject: [mg33399] Re: Creating List of Sequence Iterates
- From: "Allan Hayes" <hay at haystack.demon.co.uk>
- Date: Wed, 20 Mar 2002 01:53:02 -0500 (EST)
- References: <a76g2a$gm0$1@smc.vnet.net>
- Sender: owner-wri-mathgroup at wolfram.com
Bob:
NestList[F,F[1],3]
{F[1],F[F[1]],F[F[F[1]]],F[F[F[F[1]]]]}
--
Allan
---------------------
Allan Hayes
Mathematica Training and Consulting
Leicester UK
www.haystack.demon.co.uk
hay at haystack.demon.co.uk
Voice: +44 (0)116 271 4198
Fax: +44 (0)870 164 0565
"Bob Harris" <nitlion at mindspring.com> wrote in message
news:a76g2a$gm0$1 at smc.vnet.net...
> Howdy,
>
> I'm trying to figure out how, with a single expression, I can create a
list
> of iterates of some sequence.
>
> For example, suppose I have defined F[x_] := 3x+2 and I want to get a list
> that contains F[1], F[F[1]], F[F[F[1]]], etc. It seems like I could do
> something like
>
> iterates = Table [F[ iterates[[n-1]] ] , {n,1,20}]
>
> to get a list of the first 20 iterations of this function (assuming I had
> some way to define interates[[1]]).
>
> Anyone know how I can do that, short of writing the following function?
>
> Iterate[func_ , first_ , iterations_] := Module[ {v, ix},
> v = Table[0, {n, 1, iterations}];
> v[[1]] = first;
>
> For[ix=2, ix<=iterations, ix++, v[[ix]] = func[v[[ix-1]]] ];
>
> v
> ]
>
> Any help would be appreciated. I'm mostly interested in being pointed in
> the right direction.
>
> Thanks,
> Bob H
>
>