[R] Questions for package ts prediction

[zhu wang]

On Mon, 2003-06-09 at 03:56, Prof Brian Ripley wrote:
> You have a scoping problem: the predict method needs to find the data:
> please supply an explicit newdata argument.  Your first example works
> because `y' happens to be globally visible and be the right object.
> 
Thanks. That makes sense.

> On 9 Jun 2003, zhu wang wrote:
> 
> > I am trying to write a function to return prediction values using
> > package ts. I have written three different versions since I am not sure
> > what's wrong with my func2. func and func1 return the same results.But
> > func1 and func2 don't. In particular, the only difference between
> > "func1" and "func2" is the function variable name being y and data,
> > respectively.  But running the last line of the following script will
> > give the message:
> > 
> > Error in ts(x): object is not a matrix.
> > 
> > I am confused. Also, could somebody kindly let me what's the answer if
> > any for the following sunspot example from the package help:
> > 
> > data(sunspot)
> > (sunspot.ar <- ar(sunspot.year)) 
> > # why not just sunspot.ar <- ar(sunspot.year) ?
> 
> Have you tried it?  Please do so, and you will learn the difference!
> This idiom is widely used in the R help files.
> 
I have tried it before but now I know the trick here.

> > predict(sunspot.ar, n.ahead=25)
-- 
zhu wang <zhuw at mail.smu.edu>