Re: Question (Recurrence)
- To: mathgroup at smc.vnet.net
- Subject: [mg9407] Re: [mg9390] Question (Recurrence)
- From: Olivier Gerard <jacquesg at pratique.fr>
- Date: Wed, 5 Nov 1997 01:56:26 -0500
- Sender: owner-wri-mathgroup at wolfram.com
Czech Boguslaw !
The message "reclim" means that Mathematica in the process of evaluating
your input exceeded the recursion depth that is fixed. In your case,
this is because your reccurence formula uses terms 2 and 4 steps aback
and you have defined only the first two terms when you need the first
four terms (you need two initial terms for the odd integers, two for
the even integers).
In[1]:=
Clear [a,n,b]
a[n_] := a[n]= 1/(b^2) ( b/2 a[n-2] + (n-2) (n-3)/4 a[n-4] ); a[0]=a0;
a[1]=a1; a[2]=a2; a[3]=a3;
In[2]:=
TableForm[ Table[{n, a[n]}, {n,0,12}]] Out[2]=
(*** result skipped ***)
won't give you any trouble.
You can also redefine your recurrence to have separately the odd and the
even case since these two subsequences are independent.
do widzenia
Olivier
At 08:02 +0200 97.11.02, Boguslaw Ptaszynski wrote:
> Hello Mathematica (v.3,0 for Windows) Users,
> I have a question that I hope someone has an answer for. I have the
> following recurrence relation:
>
> a[n+2]= 1/(b^2) ( b/2 a[n] + n (n-1)/4 a[n-2] )
>
> for the indices in the series n>=2.
> I want to use the formula to determine the values of a[n] for
> n=2,3,4,...12 and give these values in the table
>
> I have written :
>
> Clear [a,n,b]
> a[n_] := a[n]= 1/(b^2) ( b/2 a[n-2] + (n-2) (n-3)/4 a[n-4] ); a[0]=a0;
> a[1]=a1;
> TableForm[ Table[{n, a[n]}, {n,0,12}]]
>
> an I have got the following message:
>
> $RecursionLimit::"reclim": "Recursion depth of \!\(256\) exceeded."
> $RecursionLimit::"reclim": "Recursion depth of \!\(256\) exceeded."
> $RecursionLimit::"reclim": "Recursion depth of \!\(256\) exceeded."
> General::"stop":
> "Further output of \!\($RecursionLimit :: \"reclim\"\) will be
> suppressed \
> during this calculation."
>
> What does the message mean? I will be happy to get any information
> abaout this problem.
>
> Boguslaw Ptaszynski