[R] help(arima) return value typo?

[Prof Brian Ripley]

On Mon, 2 Aug 2004, Rolf Turner wrote:

> Hiroyuki Kawakatsu wrote:
> 
> > in ?arima (R-1.9.1), the return value component 'convergence' should
> > be 'code'?
> 
> 	By my reading of the code of arima() --- yes, you're right.
> 
> > (it's a pity there is no reliable way to check return value documentation
> > consistency with the code, or is there?)
> 
> 	Well, looking at the code is ***pretty*** reliable!

Depends if the reader understands the code, of course. See below.

> BTW:  R core might like to note that while I was looking at the code
> I noticed the following lines:
> 
>         .
>         .
>         .
> 	trarma <- .Call("ARIMA_transPars", coef, arma, FALSE,
>             PACKAGE = "stats")
>         mod <- makeARIMA(trarma[[1]], trarma[[2]], Delta, kappa)
>         if (ncxreg > 0)
>             x <- x - xreg %*% coef[narma + (1:ncxreg)]
> ------> arimaSS(x, mod)
>         val <- .Call("ARIMA_CSS", x, arma, trarma[[1]], trarma[[2]],
>             as.integer(ncond), TRUE, PACKAGE = "stats")
>         sigma2 <- val[[1]]
>         .
>         .
>         .
> 
> The line indicated above seems to be hanging there, doing nothing.
> Should ``arimaSS(x, mod)'' get assigned to some variable here, or
> should that line simply be removed?  (If the former, it's a bug;
> if the latter, a typo.)

There are other possibilities, and it is neither.

Hint: you don't think all unassigned calls to options() or 
library.dynam() are bugs or typos, do you?

-- 
Brian D. Ripley,                  ripley at stats.ox.ac.uk
Professor of Applied Statistics,  http://www.stats.ox.ac.uk/~ripley/
University of Oxford,             Tel:  +44 1865 272861 (self)
1 South Parks Road,                     +44 1865 272866 (PA)
Oxford OX1 3TG, UK                Fax:  +44 1865 272595