question about nest
- To: mathgroup at christensen.cybernetics.net
 - Subject: [mg1947] question about nest
 - From: Bob Hanlon <hanlonbo at sgate.com>
 - Date: Sat, 26 Aug 1995 00:09:03 -0400
 
I recommend that you use a pure function.
Bob Hanlon
_______________
Table[ Nest[ g[#, a]&, x, n], {n, 0, 4} ] // TableForm
x
g[x, a]
g[g[x, a], a]
g[g[g[x, a], a], a]
g[g[g[g[x, a], a], a], a]
f[x_, a_] := a * x * (1 - x);
f[x_, a_, n_Integer] := Nest[ f[#, a]&, x, n ];
Table[ f[x, a, n], {n, 0, 4} ] // TableForm
x
a (1 - x) x
 2
a  (1 - x) x (1 - a (1 - x) x)
 3                                   2
a  (1 - x) x (1 - a (1 - x) x) (1 - a  (1 - x) x (1 - a (1 - x) x))
 4                                   2
a  (1 - x) x (1 - a (1 - x) x) (1 - a  (1 - x) x (1 - a (1 - x) x)) 
 
        3
  (1 - a  (1 - x) x (1 - a (1 - x) x) 
 
           2
     (1 - a  (1 - x) x (1 - a (1 - x) x)))
>  Newsgroups: comp.soft-sys.math.mathematica
>  From: ORLANDO LUIS GOULART PERES <orlando at axp.ift.unesp.br>
>  Subject: question about nest
>  Message-ID: <DDsGrD.Gy6 at wri.com>
>  Date: Thu, 24 Aug 1995 00:16:24 GMT
>  
>  Dear Wizards
>  
>  I have a function with two variables
>  f[x_,a_]:=a*x*(1-x)
>  And I need the n-compose function
>  Nest[f,x,n]
>  But Mathematica look for a function f[x] and not f[x,a]
>  Is this possible to use Nest with this two variable function?
>  For example, I need
>  f[x,a], f[f[x,a],a], f[f[f[x,a],a],a] .
>  Later I will put many values for "a" .
>  Regards
>  Orlando Peres