R help - Mar 2009 - modifying a built in function from the stats package (fixing arima)

Dear members of the list,

I''m a beginner in R and I''m having some trouble with:
"Error in
optim(init[mask], armafn, method = "BFGS", hessian = TRUE, control
optim.control,  :
  non-finite finite-difference value [8]"

when running "arima".

I''ve seen that some people have come accross the same problem:
https://stat.ethz.ch/pipermail/r-help/2008-August/169660.html

So I''d like to modify the code of arima to change the optimization
function
with another one that handles these problems automatically , however I
don''t
find the way to do it and
http://tolstoy.newcastle.edu.au/R/e6/help/09/01/2476.html points out a way
that doesn''t work for me:

* If I type edit(arima) and I modify it, changes are not saved,
* If I copy the code and I save it like a different function, I get the hard
error: "Error in Delta %+% c(1, -1) : object "R_TSconv" not
found"

Anybody can give me a hint? I miss matlab''s easy way of doing this
("edit
function.m").

Thanks in advance

MarC (AleaSoft)

	[[alternative HTML version deleted]]

On 5/03/2009, at 10:00 PM, Marc Anonym wrote:
> It is quite exagerated that I have to build R in order to modify an  
> R file
> without messing with dlls, and I think it would be interesting to  
> make this
> process easier, but for now I'm happy to be productive again.
There is probably (almost surely?) an easier way, but I'm too much of  
a naif
to know about it.

	cheers,

		Rolf

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