Displaying 8 results from an estimated 8 matches for "ncxreg".
2009 Mar 06
0
modifying a built in function from the stats package (fixing arima) (CONCLUSIONS)
...od$theta, mod$Delta,
mod$a, mod$P, mod$Pn, as.integer(0), TRUE)
}
armafn <- function(p, trans) {
par <- coef
par[mask] <- p
trarma <- .Call(R_ARIMA_transPars, par, arma, trans)
Z <- upARIMA(mod, trarma[[1]], trarma[[2]])
if (ncxreg > 0)
x <- x - xreg %*% par[narma + (1:ncxreg)]
res <- .Call(R_ARIMA_Like, x, Z$phi, Z$theta, Z$Delta,
Z$a, Z$P, Z$Pn, as.integer(0), FALSE)
s2 <- res[1]/res[3]
0.5 * (log(s2) + res[2]/res[3])
}
armaCSS <- function(p) {
p...
2013 Mar 22
0
predict.Arima error "'xreg' and 'newxreg' have different numbers of columns"
...own in (*)).
(*):
debugging in: predict.Arima(fit, newxreg = indep, n.ahead = 1)
debug: {
myNCOL <- function(x) if (is.null(x))
0
else NCOL(x)
rsd <- object$residuals
xr <- object$call$xreg
xreg <- if (!is.null(xr))
eval.parent(xr)
else NULL
ncxreg <- myNCOL(xreg)
if (myNCOL(newxreg) != ncxreg)
stop("'xreg' and 'newxreg' have different numbers of columns")
class(xreg) <- NULL
xtsp <- tsp(rsd)
n <- length(rsd)
arma <- object$arma
coefs <- object$coef
narma <- su...
2010 Mar 31
1
predict.Arima: warnings from xreg magic
...urce,
predict.Arima <-
function (object, n.ahead = 1, newxreg = NULL, se.fit = TRUE, ...)
{
myNCOL <- function(x) if (is.null(x)) 0 else NCOL(x)
rsd <- object$residuals
xr <- object$call$xreg
xreg <- if (!is.null(xr)) eval.parent(xr) else NULL
ncxreg <- myNCOL(xreg)
if (myNCOL(newxreg) != ncxreg)
stop("'xreg' and 'newxreg' have different numbers of columns")
class(xreg) <- NULL
xtsp <- tsp(rsd)
n <- length(rsd)
arma <- object$arma
coefs <- object$coef...
2009 Feb 17
0
What's the predict procedure of ARIMA in R?
...t;Arima")
function (object, n.ahead = 1, newxreg = NULL, se.fit = TRUE,
...)
{
myNCOL <- function(x) if (is.null(x))
0
else NCOL(x)
rsd <- object$residuals
xr <- object$call$xreg
xreg <- if (!is.null(xr))
eval.parent(xr)
else NULL
ncxreg <- myNCOL(xreg)
if (myNCOL(newxreg) != ncxreg)
stop("'xreg' and 'newxreg' have different numbers of columns")
class(xreg) <- NULL
xtsp <- tsp(rsd)
n <- length(rsd)
arma <- object$arma
coefs <- object$coef
narma <- s...
2004 Aug 02
3
help(arima) return value typo?
in ?arima (R-1.9.1), the return value component 'convergence' should be
'code'?
(it's a pity there is no reliable way to check return value documentation
consistency with the code, or is there?)
h.
----------------------------------
Hiroyuki Kawakatsu
School of Management and Economics
25 University Square
Queen's University, Belfast
Belfast BT7 1NN
Northern Ireland
2004 Aug 02
3
help(arima) return value typo?
in ?arima (R-1.9.1), the return value component 'convergence' should be
'code'?
(it's a pity there is no reliable way to check return value documentation
consistency with the code, or is there?)
h.
----------------------------------
Hiroyuki Kawakatsu
School of Management and Economics
25 University Square
Queen's University, Belfast
Belfast BT7 1NN
Northern Ireland
2009 Mar 26
1
arima, xreg, and the armax model
Hello all,
I''m having fun again with the arima function. This time I read in:
http://www.stat.pitt.edu/stoffer/tsa2/R_time_series_quick_fix.htm
<<It has recently been suggested (by a reliable source) that using xreg in
arima() does NOT fit an ARMAX model [insert slap head icon here]. This will
be investigated as soon as time permits.>>
(by R.H. Shumway & D.S. Stoffer)
2009 Mar 01
0
Variable scope.
...also passed as reference hence changes to Z$a should also be seen in mod$a? In the arima code the references to x and mod seem to be essentially global variables as armafn is 'nested' in arima. Will changes to x also be reflected in the original x? (Like x <- x - (xreg %*% par[narma + (1:ncxreg)))
Thank you.
Kevin