Displaying 20 results from an estimated 7000 matches similar to: "(1) arima.mle implementation; (2) r-newbie forum"
2001 Dec 16
3
Arima
I did a regression with ARMA errors using arima0 with
ari<-arima0(y,order=c(2,0,2),xreg=reg1,delta=-1)
or
ari<-arima0(y,order=c(2,0,2),xreg=reg1)
where reg1 is the matrix of the regressors and when I see diag(ari$var.coef)
I get negative terms. Do you know what this mean ?
I try to change transform.pars to 0 or 1 but this crash R on Windows.
Is it possible to test the significativity
2002 Mar 08
4
ARMA and ARIMA modeling
I'd like to play with ARIMA models of stock prices, but I am a complete novice.
Could some kind soul explain the relationship among packages "ts", "tseries",
"dse", "dse2", and "fracdiff"? Are they 'competing' products or does one
depend on another? Where would be the best place for a novice to begin?
Thanks for any advice.
PS. I
2000 Dec 30
3
ARIMA
Thanks,
Can't find an ARIMA in base, dse1/2 or tseries, only references to. What
package is it in?
Thanks again!
Best regards,
/fb
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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)
2003 Jan 09
2
using arima() function
HI, there,
When i use R, i tried to use function arima(), it complains:
Error: couldn't find function "arima"
But when I type "help.search("arima") ",
I got arima() poped up..
arima(ts) ARIMA Modelling of Time Series
arima.sim(ts) Simulate from an ARIMA Model
arima0(ts) ARIMA Modelling of Time Series -- Preliminary
2001 Apr 24
1
ARIMA and GARCH
Hello,
I would like to study time series with ARIMA and GARCH models.
I installed R-Plus and its libraries but when I try to execute the function
arima0, It answers that the function does not exist.
Could you help me or give me references of papers dealing with arima and garch
in R-Plus?
Thanks
Beno?t,
___________________________________
Mr. Beno?t LACHERON
Rue de l'industrie, 44,
1040
1999 Nov 07
2
arima0() (PR#314)
Full_Name: Ahmad Abu Hammour
Version: rw0651
OS: windows 95
Submission from: (NULL) (63.23.128.44)
Although I know that "ts package" is preliminary, I wanted to compare the
results from R and SPSS. I ran ARIMA(2,1,2) in both softwares. I got NaN in
standard errors of coefficients from R and real figures from SPSS. I changed
"delta" in R to match that used by SPSS, I received
2000 Apr 26
1
Factor Rotation
How does one rotate the loadings from a principal component analysis?
Help on function prcomp() from package mva mentions rotation:
Arguments
retx a logical value indicating whether the rotated
variables should be returned.
Values
rotation the matrix of variable loadings (i.e., a matrix
whose olumns contain the eigenvectors). The
function princomp returns this in the element
2003 Apr 30
2
Bug in arima?
I'm using the fixed argument in arima. Shouldn't ar4, ar5, and ar6
display as zero in the output?
Call:
arima(x = window(log(hhprice), start = c(1990, 1), end = c(2003, 3)),
order = c(7,
1, 0), xreg = window(ts.union(exa1 = lag(exa, -1), exa12 = lag(exa,
-12), exb1 = lag(exb, -1), exc1 = lag(exc, -1), exc12 = lag(exc,
-12)), start = c(1990, 1), end = c(2003, 3)),
2004 Aug 29
1
predict(arima)
Dear All,
R 1.9.1, Windows
When copying and pasting a few lines from the 'predict.Arima' help, I
get an error message:
> data(lh)
> predict(arima(lh, order = c(3,0,0)), n.ahead = 12)
Error in eval(expr, envir, enclos) : Object "xreg" not found
On the other hand, the following is OK:
> data(lh)
> predict(arima0(lh, order = c(3,0,0)), n.ahead = 12)
$pred
Time
2001 Feb 17
0
Krebs for R (was Re: canonical correspondence analysis)
R-ecologists:
Anyone wanting to create a Krebs package for R can do so using the
C-source code avalaible at:
ftp://gause.biology.ualberta.ca/pub/jbrzusto/krebs/source.zip
Barry J. Cooke Current mailing address:
Ph.D. Candidate 3971 NW 23 Circle
Environmental Biology and Ecology Gainesville, Florida, USA
Department of Biological Sciences 32605
2009 Apr 22
1
arima
Hi,
I have a suggestion for the fonction arima and arima0. I think you
should not call the constant an intercept because it creates confusion.
It is not really an intercept but a mean. For an AR(1) the intercept mu
should be defined as:
X(t)=mu + phi X(t-1) + e(t)
What you call intercept mu is rather defined as
(X(t)-mu) = phi (X(t-1)-mu)) + e(t)
which is not a common way to define an
2004 Jun 17
1
Error with arima()
Could someone please give a brief explanation, or pointer to an explanation,
of the following error:
> arima(ts.growth, order = c(1,0,0),include.mean=T)
Error in arima(ts.growth, order = c(1, 0, 0), include.mean = T) :
non-stationary AR part from CSS
and why it does not arise with
> arima0(ts.growth, order = c(1,0,0))
Many thanks
____________________________
Dr. Daniel P. Bebber
2007 Mar 13
1
estimating an ARIMA model with constraints
Hi,
I am trying to estimate an ARIMA model in the case where I have some
specific knowledge about the coefficients that should be included in the
model. Take a classical ARIMA (or even ARMA) model:
P(B) X(t) = Q(B) epsilon(t),
where X(t) is the data, epsilon is a white noise, B is the backward operator
and P and Q are some polynoms. Additionally, assume that you know in advance
how P and Q
2001 Oct 31
3
Defining time series objects
Hi All,
I am new to R, having used S-plus a number of years back.
I would like to set up a time series object for forecasting, with data
collected daily between 5th April 2001 and 16th September 2001.
Any help would be most appreciated as I have been unable to find any
suitable examples in the documentation.
Thanks,
Mark.
2006 Oct 19
1
predict.Arima question
Hi,
I am trying to forecast a model using predict.Arima
I found arima model for a data set: x={x1,x2,x3,...,x(t)}
arima_model = arima(x,order=c(1,0,1))
I am forecasting the next N lags using predict:
arima_pred = predict(arima_model,n.ahead = N, se.fit=T)
If I have one more point in my series, let's say x(t+1). I do not want to
recalibrate themodel, I just want to forecast the next N-1
2004 Mar 22
1
problem with seasonal arima
hallo to all
I've to calculate an arima model and I need only the
first and 365 th parameter and also the sar1 and the
intercept, so I'm traing with:
arima(X,order=c(365,0,0),seasonal=list(order=c(1,0,0),..),fixed=c(NA,rep(0,363),NA,NA,NA),transform.pars=F)
but the error answer is:
Error in polyroot(z) : polynomial degree too high (49
max)
also there are problems in allocating memory
2000 Aug 05
1
new arima source code
Greetings:
I was looking for the source code for the new arima procedure. I checked
the floppies directory and downloaded R-devel-2.tar.gz but this
only included the old starma.f. Is the new code available yet?
Thanks,
George
gwtim at 2xtreme.net
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2009 Nov 16
1
ARMAX model fitting with arima
I am trying to understand how to fit an ARMAX model with the arima
function from the stats package. I tried the simple data below, where
the time series (vector x) is generated by filtering a step function
(vector u, the exogenous signal) through a lowpass filter with AR
coefficient equal to 0.8. The input gain is 0.3 and there is a 0.01
normal white noise added to the output:
x <- u