Displaying 20 results from an estimated 1000 matches similar to: "RE. arimaX"
2004 Apr 01
1
arimax...
Hallo all
can someone explain me how the exogenus variables work
in the arimax models is not clear for me...
Thanks Michele
2010 May 04
1
How to make predictions with the predict() method on an arimax object using arimax() from TSA library
Hi R Users,
I'm fairly new to R (about 3 months use thus far.)
I wanting to use the arimax function from the TSA library to incorporate some exogenous inputs into the basic underllying arima model.Then with that newly model of type arimax, I would like to make a prediction.
To avoid being bogged down with issues specific to my own work, I would like to refer to readers to the example
2011 Oct 02
0
Arimax First-Order Transfer Function
Dear list members,
I am a (very) recent convert to R and I am hoping you can help me with a
problem I'm having. I'm trying to fit a first-order transfer function to an
ARIMA intervention analysis using the "arimax" function. The data was
obtained from McCleary & Hay (1980) (via Rob Hyndman's Time Series Library:
http://robjhyndman.com/tsdldata/data/schizo.dat). It has
2008 Oct 15
1
Forecasting using ARIMAX
Dear R-helpers,
I would appreicate if someone can help me on the transfer parameter in ARIMAX and also see what I am doing is correct.
I am using ARIMAX with 2 Exogeneous Variables and 10 years data are as follows:
DepVar Period, depVar, IndepVar1 Period, indepVar1, IndepVar2 Period, indepVar2
Jan 1998,708,Jan 1998,495,Jan 1998,245.490
Feb 1998,670,Feb 1998,421.25,Feb 1998,288.170
Mar
2018 May 25
0
Query on the Arimax modeling results
Hi R team,
We?ve run Arimax models in R. We had a lot of queries around the
interpretation of the outputs.
*Dependent variable =* Volume (Growth %)
*Independent Variables =* 3 Macroeconomic variables (Growth %)
Following is the line of code
Arimax.Model <- auto.arima(y = input.data[,"Volume"], xreg =
input.data[,model.vars], seasonal = F)
Following is the output
2013 Feb 21
2
Arimax with intervention dummy and multiple covariates
Hi
I'm trying to measure the effect of a policy intervention (Box and Tiao, 1975).
This query has to do with the coding of the model rather than with the particulars of my dataset, so I'm not providing the actual dataset (or a simulated one) in this case, apart from some general description.
The time series are of length n=34 (annual observations between 1977 and 2010). The policy
2009 May 04
2
About the Transfer Function Model(ARIMAX)
Dear ALL,
I would appreciate if someone help me by letting me know the code of above model in R.I would request you to please let me know how i could
make arimax model in auto.arima.
Regards
Ramanath
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2011 Nov 15
0
Forescasting using predict() in an object of class arimax when there is an outlier IO in the model.
Forescasting using predict() in an object of class arimax when there is an
outlier IO in the model.
Hi R users
I have a problem when a use the predict() method in an object of class
arimax ( These objects are the results of the implementation of the function
arimax() from the TSA library) . The object is a model of a time series in
which I identified an IO oulier at the element 33 of the serie
2008 Jul 08
0
forecast & xreg
Dear all,
I am fitting an arimax (arima with some extra explanatory variables)
model to a time series. Say, I have a Y (dependent variable) and an X
(explanatory).
Y is 100 observations (time series) and X is 100 + 20 (20 to use for the
forecast horizon).
I can not make xreg work with the forecast function for an arima fit.
The "predict" function seems to be working but the
2009 Jul 15
2
storing lm() results and other objects in a list
to clean up some code I would like to make a list of arbitrary length
to store?various objects for use in a loop
sample code:
############ BEGIN SAMPLE ##############
# You can see the need for a loop already
linearModel1=lm(modelSource ~ .,mcReg)
linearModel2=step(linearModel1)
linearModel3=lm(modelSource ~ .-1,mcReg)
linearModel4=step(linearModel3)
#custom
linearModel5=lm(modelSource ~ .
2009 May 05
0
Time series ARIMAX and multivariate models
Dear Lillian,
I would request you if you provide me the knowledge of how build ARIMAX model in R? It would be great help for me.
Thanks
Ramanath
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2005 Sep 08
1
Time series ARIMAX and multivariate models
Dear List,
The purpose of this e-mail is to ask about R time series procedures - as a
biologist with only basic time series knowledge and about a year's
experience in R.
I have been using ARIMAX models with seasonal components on seasonal data.
However I am now moving on to annual data (with only 34 time points) and
understand that ARIMA is not suitable for these shorter time periods -
does
2004 Apr 18
1
arima
Hola!
I got problems using an objects returned from arima
(in KalmanSmooth(my.ts, ModArima$model), because
my.ts showed up to have storage mode "integer" (is.integer(my.ts was
TRUE).
Should storage.mode() of a ts be allowed to be integer,
should ts() someplace say storage.mode(ts.out) <- "double", or
maybe inside arima()
storage.mode(x) <- "double"
2003 Apr 21
2
Anyone Familiar with Using arima function with exogenous variables?
I've posted this before but have not been able to locate what I'm doing
wrong. I cannot determine how the forecast is made using the estimated
coefficients from a simple AR(2) model when there is an exogenous
variable. Does anyone know what the problem is? The help file for arima
doesn't show the model with any exogenous variables. I haven't been able
to locate any documents
2004 May 02
1
arima problems when using argument fixed=
As I am reading ?arima, only NA entries in the argument fixed=
imports. The following seems to indicate otherwise:
x <- arima.sim(model=list(ar=0.8), n=100) + (1:100)/50
> t <- 1:100
> mod1 <- lm(x ~ t)
>
> init1 <- c(0, coef(mod1)[2])
> fixed1 <- c(as.numeric(NA), 0)
>
> arima(x, order=c(1,0,0), xreg=t, include.mean=FALSE, init=init1,
fixed=fixed1)
2003 Apr 16
0
arima function - estimated coefficients and forecasts
I'm using the arima function to estimate coefficients and also using
predict.Arima to forecast. This works nicely and I can see that the
results are the same as using SAS's proc arima.
I can also take the coefficent estimates for a simple model like
ARIMA(2,1,0) and manually compute the forecast. The results agree to 5
or 6 decimal places. I can do this for models with and without
2008 Jul 23
1
Time series reliability questions
Hello all,
I have been using R's time series capabilities to perform analysis for quite
some time now and I am having some questions regarding its reliability. In
several cases I have had substantial disagreement between R and other packages
(such as gretl and the commercial EViews package).
I have just encountered another problem and thought I'd post it to the list. In
this case,
2004 Feb 04
1
arima function
Hello,
I am a beginner user of R and I would like to estimate a model with AR
errors. I use arima function:
modele
<-arima(conso,xreg=var.exogenes,order=c(ordre,0,0),include.mean=TRUE,method
="CSS")
My inputs are dummies for each month except one, and the same thing for
each day and each hour. I have this error message:
Warning message:
possible convergence problem: optim gave
2001 Aug 28
1
ARIMAX
I am new to R-system. I have found time series
modeling package whereby ARIMA model can be developed.
I would like to know if there exists some package
within R-system whereby parameters of transfer
function model can be estimated using the
preliminaraly identified model.
Any sort of help in this regard will be highly
appreciated.
MG
__________________________________________________
Do You
2010 May 12
2
Reading R code help--Beginner
Hi, I am brand new to R and not familiar with the language, though I
have been reading the manuals and making some slow going progress. I am
working with some source code from a Global Vector Auto -Regressive
program written by Ranier Puhr from the R-forge group. I need help
interpreting the processes of the following code.
I am going to
post in parts since it's pretty long:
GVAR