[R] handling recursion relation

[jim holtman]

Look at your first function:

Grx<-function(x,r)
{
G0=Grx(x,0)
G0=1;
fu1<-function(t){exp(-t^2/(2*r*(r+1)))*Grx(x,r-1)}
return(integrate(fu1,0,x)$value)
}

It immediately calls itself for infinite recursion.  How did you
expect to stop it?  I would have expected some type of test before the
call.  I put a counter in and it was 1661 levels down in the call at
the error.

On Fri, Aug 20, 2010 at 9:33 AM, Shant Ch <sha1one at yahoo.com> wrote:
> Hi,
>
> I wanted to compute the value of the function ifn at certain values of n. But I
> am receiving the following error when I was using the following code(given at
> the end).
>
> Error: evaluation nested too deeply: infinite recursion / options(expressions=)?
>
> I feel that since the function Grx is recursively related, perhaps making the
> code too complicated too handle. Can anyone let me know if there is any other
> way to handle this problem?
>
>
> d1=10.5
> Grx<-function(x,r)
> {
> G0=Grx(x,0)
> G0=1;
> fu1<-function(t){exp(-t^2/(2*r*(r+1)))*Grx(x,r-1)}
> return(integrate(fu1,0,x)$value)
> }
>
> grx<-function(x,r)
> {
> Grx(x)*exp(-x^2/(2*(r+1)))
> }
>
> ifn<-function(n)
> {
> w=n*d1/2;S1=0;
> for(k in 1:(n-1))
> {
>  S1=S1+choose(n,k)*grx(w,k)*grx(w,n-k-1)
> }
> return(S1);
> }
>
> ifn(5)
>
> Thanks in advance.
>
> Shant
>
>
>
>
>        [[alternative HTML version deleted]]
>
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>



-- 
Jim Holtman
Cincinnati, OH
+1 513 646 9390

What is the problem that you are trying to solve?