I'm playing with predict.Arima in the 3/19/02 development snapshot of
R-devel.
The following produces an error message because x is not of class
"ts":
R> x <- rnorm(20)
R> obj <- arima(x, c(2,0,0))
R> predict(obj)
Error in round(x, digits) : Non-numeric argument to mathematical function
Granted the documentation for arima says x should be a time-series, but why not
accommodate simple vectors? I think it would suffice to change this line:
xtsp <- tsp(data)
in predict.Arima to this:
xtsp <- tsp(hasTsp(data))
Also, a minor documentation typo: the help file for predict.Arima refers to the
function as "predict.arima" at one point.
--
-- David Brahm (brahm@alum.mit.edu)
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Prof Brian D Ripley
2002-Apr-04 05:35 UTC
[Rd] Re: predict.Arima fails when x is not a time-series
On Wed, 3 Apr 2002, David Brahm wrote:> I'm playing with predict.Arima in the 3/19/02 development snapshot of R-devel.That's quite old.> The following produces an error message because x is not of class "ts": > R> x <- rnorm(20) > R> obj <- arima(x, c(2,0,0)) > R> predict(obj) > Error in round(x, digits) : Non-numeric argument to mathematical function > > Granted the documentation for arima says x should be a time-series, but why not > accommodate simple vectors?Because it is not possible to specify the time base correctly when predicting.> I think it would suffice to change this line: > xtsp <- tsp(data) > in predict.Arima to this: > xtsp <- tsp(hasTsp(data)) > > Also, a minor documentation typo: the help file for predict.Arima refers to the > function as "predict.arima" at one point.Not any more it doesn't.> -- > -- David Brahm (brahm@alum.mit.edu) >-- Brian D. Ripley, ripley@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 272860 (secr) Oxford OX1 3TG, UK Fax: +44 1865 272595 -.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.- r-devel mailing list -- Read http://www.ci.tuwien.ac.at/~hornik/R/R-FAQ.html Send "info", "help", or "[un]subscribe" (in the "body", not the subject !) To: r-devel-request@stat.math.ethz.ch _._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._