Displaying 20 results from an estimated 4000 matches similar to: "STARMA model (Space-Time ARMA)"
2004 Jan 20
2
question
Je suis étudiant en DEA et j'élabore un mémoir dans lequel j'applique le modèle STARMA ,
Pouvez vous ,s'il vous plait, m'envoyer l'algorithme de calcul ces STACF et STPACF de ce model afin de débuter mon estimation de ce modéle sur R
Merci d'avance.
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2004 Feb 12
0
How to predict ARMA models?
Hi all,
I am fitting an ARMA(1,(1,4)) model.
y(t) = a*y(t-1) + e(t) + b1*e(t-1) + b4*e(t-4)
> arma1.14 <- arma(series, lag=list(ar=1, ma=c(1,4)),
+ include.intercept = F, qr.tol = 1e-07)
works fine:
Coefficient(s):
ar1 ma1 ma4
0.872 -0.445 0.331
I want to forecast 50 periods.
I could not find a 'predict' function for ARMA models.
I
2011 Oct 12
0
ARMA and prediction
Hello,
I am running an ARMA model to run forecast for changes in S&P 500 prices.
My ARMA calculations look as follows
armacal <- arma( spdata, order = c(0,4), lag = list(ma = c(1,2,4)) )
Output:
Call:
arma(x = spdata, order = c(0, 4), lag = list(ma = c(1, 2, 4)) )
Coefficient(s):
ma1 ma2 ma4 intercept
-0.073868 0.058020 -0.081292 0.007082
All's
2007 Nov 02
0
Significance-Problems by using arma/xreg.
Hello.
I've got a problem with arma/xreg.
I would like to get a better model-fit by implenting
some external explanatory variable, so I thought I can
implement it by expand the arima-function with an
xreg-argument:
I have two stationary data vectors y and x of length
201:
y <-
2007 Oct 22
0
beginner's tutorial, books, etc re: time-series analysis, ARMA/ARIMA models...
Thomas,
may I also suggest, from the Documentation>Contributed section of CRAN,
"Econometrics in R" by Grant Farnsworth
http://cran.at.r-project.org/doc/contrib/Farnsworth-EconometricsInR.pdf
(see the chapter on Time series) and, in case you can read Italian,
"Analisi delle serie storiche con R" by Vito Ricci
http://cran.at.r-project.org/doc/contrib/Ricci-ts-italian.pdf
2003 Nov 24
0
link between arima and arma fit
Hi dear sirs,
I am wondering why the fit of the time serie x with an arima and the fit of
diff(x) with an arma (same coeff p & d) differ one from another
here are the output of R:
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
> modelarma<-arma(diff(x),c(7,5))
> modelarma
Call:
arma(x = diff(x), order = c(7, 5))
Coefficient(s):
ar1 ar2 ar3 ar4 ar5 ar6 ar7 ma1 ma2
0.06078
2009 Oct 13
0
How to specify an ARMA(1, [1,4]) model? Solved
On Tue, Oct 13, 2009 at 5:06 PM, Rolf Turner <r.turner@auckland.ac.nz>wrote:
>
> Not clear to me what the OP really wants. Perhaps the seasonal
> model is what's required; perhaps an arima(1,0,4) model with
> theta_2 and theta_3 constrained to be 0. The latter can be
> achieved with
>
> arima(x,order=c(1,0,4),fixed=c(NA,NA,0,0,NA,NA))
>
> Or perhaps
2009 Oct 13
1
How to specify an ARMA(1, [1,4]) model?
Hi,
I'm trying to model an ARMA(1,[1,4]),
i.e. I want only lags 1 and 4 of the Moving Average part.
It's the '[1,4]' part that is giving me a problem.
I've tried different arma's and arima's in different packages, namely:
packages tseries, fArma, FinTS, timeSeries, TSA, Zelig, ds1, forecast
For example, with package FinTS:
> ( ARIMA(y, order=c(1,0,c(1,4))) )
2008 Mar 21
1
tseries(arma) vs. stats(arima)
Hello,
The "arma" function in the "tseries" package allows estimation of models
with specific "ar" and "ma" lags with its "lag" argument.
For example: y[t] = a[0] + a[1]y[t-3] +b[1]e[t-2] + e[t] can be estimated
with the following specification : arma(y, lag=list(ar=3,ma=2)).
Is this possible with the "arima" function in the
2009 May 26
1
R for arma mdel with constraints on parameters
Hi,
i am learning R recently and find it very helpful in time series model.
In ARMA model, given (p,q) it can get the estimation of a[i] and b[j] easily with arima() function.
X[t] = a[1]X[t-1] + ... + a[p]X[t-p] + e[t] + b[1]e[t-1] + ... + b[q]e[t-q]
but in my recent data model, i met a problem. In the ARMA model, p and q are fixed, but there are some constraints in the parameters
2004 Jul 04
1
Re: Seasonal ARMA model
> It might clarify your thinking to note that a seasonal ARIMA model
> is just an ``ordinary'' ARIMA model with some coefficients
> constrained to be 0 in an efficient way. E.g. a seasonal AR(1) s =
> 4 model is the same as an ordinary (nonseasonal) AR(4) model with
> coefficients theta_1, theta_2, and theta_3 constrained to be 0. You
> can get the same answer as from
2013 Feb 28
1
ARMA and AR in R
Hello,
I would like to compute ARMA and AR using arima-function in R.
My question is: If I have Null=zero values in my data, what should I do?
Remove ? or doesn't matter for ARIMA-models and I can estimate my
coefficients including zero values in data in arima-function in R ? What
is the better way? How to manage the data for ARIMA estimation?
Thank you.
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2003 Aug 14
1
filter ARMA process
Hi
given an ARMA process and the AR and MA coefficients I need the residuals.
arima() calculates the residuals together with the best AR and MA
coefficients, but I need the coefficients to take known values.
In S-PLUS there is a function arima.filt(). Is there something similar in
R?
Thanks for any help,
Matthias Budinger
2013 May 09
0
ARMA(p,q) prediction with pre-determined coefficients
I have the following time series model for prediction purposes
*Loss_t = b1* Loss_(t-1) + b2*GDP_t + b3*W_(t-1)* where W_t is the
usual white noise variable.
So this is similar to ARMA(1,1) except that it also contains an extra
predictor, GDP at time t.
I have only 20 observations on each variable except GDP for which I know
till 100 values.
And most importantly,I have also calculated
2004 Feb 17
2
Installing package on R
Hello
I have a XP on my Pc ,and I would like to install the splancs package on my machine
what is the step for implementing them on my library?
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2004 Jul 25
1
Multivariate ARMA Model
Hi R-Community,
so far I dealt with univariate processes and used the function "arima" to
estimate an ARMA(1,1)-model. For multivariate processes there are the
functions "estVARXar" and "estVARXls" from package "DSE". But how can I
estimate an VARMA(1,1)-model, or even better determine the orders and
estimate the parameters?
Much thanks in advance,
Hagen
2012 Mar 01
2
Robust ARMA Fitting in R?
Hello, BODY { font-family:Arial, Helvetica,
sans-serif;font-size:12px; }
Does any one know if there are any functions/packages available in R
for robust fitting of ARMA time series models (e.g., similar to the
function arima.rob() in S-PLUS)?
Many thanks and kind regards,
Isabella
Isabella R. Ghement, Ph.D.
Ghement Statistical Consulting Company
301-7031 Blundell Road,
2006 Dec 06
1
Standar errors arma models
Why the standadard errors of the coefficientes of the arma
models fited by using the arima procedure in the stats
package doesnt coincide with that of S+, minitab or SAS?
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2011 Aug 30
2
ARMA show different result between eview and R
When I do ARMA(2,2) using one lag of LCPIH data
This is eview result
>
> *Dependent Variable: DLCPIH
> **Method: Least Squares
> **Date: 08/12/11 Time: 12:44
> **Sample (adjusted): 1970Q2 2010Q2
> **Included observations: 161 after adjustments
> **Convergence achieved after 14 iterations
> **MA Backcast: 1969Q4 1970Q1
> **
> **Variable Coefficient Std.
2005 Jun 14
1
using forecast() in dse2 with an ARMA model having a trend component
(My apologies if this is a repeated posting. I couldn't find any trace
of my previous attempt in the archive.)
I'm having trouble with forecast() in the dse2 package. It works fine
for me on a model without a trend, but gives me NaN output for the
forecast values when using a model with a trend. An example:
# Set inputs and outputs for the ARMA model fit and test periods