Displaying 20 results from an estimated 4000 matches similar to: "Arima"
2013 May 02
1
warnings in ARMA with other regressor variables
Hi all,
I want to fit the following model to my data:
Y_t= a+bY_(t-1)+cY_(t-2) + Z_t +Z_(t-1) + Z_(t-2) + X_t + M_t
i.e. it is an ARMA(2,2) with some additional regressors X and M.
[Z_t's are the white noise variables]
So, I run the following code:
for (i in 1:rep) { index=sample(4,15,replace=T)
final<-do.call(rbind,lapply(index,function(i)
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.
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
2011 Nov 14
1
string to list()
I can get an array of strings for the data that I want using 'paste()' as
follows:
paste('ma', 1:am$arma[2], '=', coef(am)[1:am$arma[2] + am$arma[1]], sep='')
This results in a vector of strings like:
[1] "ma1=1.17760133668255" "ma2=0.649795570407939" "ma3=0.329456750858276"
What I would like is
fixed.pars <-
2002 Apr 02
1
predict with arima0
Dear R People:
I'm trying to use the predict command on an arima0 object.
I do the following:
xm.arma <- arima0(xm2,order=c(1,0,1))
predict(xm.arma,n.ahead=2)
and I get the message:
Error in round(x, digits) : Non-numeric argument to mathematical function
Any ideas what the problem might be, please?
R version 1 4 1 on Windows.
Thanks in advance!
Sincerely,
Erin Hodgess
Associate
2008 Nov 20
2
Reformatting a table
Hi !
I am new to R. Can somebody help me in reformatting huge output files ,i.e, rearranging sets of columns in specific order.
For example: I have data for three compunds 1, 2 and 3
file1:
ID CA1 CA3 CA2 MA2 MA1 MA3
1 14 15 13 7 12 3
2 19 7 12 10 14 5
3 21 12 19 6 8 9
to
File 2:
ID CA1 CA2 CA3 MA1 MA2 MA3
1 14 13 15 12 7 3
2 19 12 7 14 10 5
3 21 19 12 8 6 9
or File3:
ID
2005 Oct 13
1
arima: warning when fixing MA parameters.
I am puzzled by the warning message in the output below. It appears
whether or not I fit the seasonal term (but the precise point of doing
this was to fit what is effectively a second seasonal term). Is there
some deep reason why AR parameters
("Warning message: some AR parameters were fixed: ...")
should somehow intrude into the fitting of a model that has only MA
terms?
>
2010 Jul 15
1
scope of an argument in a function
Hi
I am trying to define a function fu() in the following way but when I try to
run I get the error that ma1 is not found. I am not sure where I am going
wrong? Does the scope of ma1 not extend to an expr.frame object?
expr.frame() is under library tradesys.
function (y,ma1,ma2)
{
x <- y[, c("Open","Close")]
d <- expr.frame(x, list(MAf=quote(SMA(Close, ma1)),
2011 Sep 09
2
Different results with arima in R 2.12.2 and R 2.11.1
Hello , I have estimated the following model, a sarima:
p=9
d=1
q=2
P=0
D=1
Q=1
S=12
In R 2.12.2
Call:
arima(x = xdata, order = c(p, d, q), seasonal = list(order = c(P, D, Q),
period = S),
optim.control = list(reltol = tol))
Coefficients:
ar1 ar2 ar3 ar4 ar5 ar6 ar7 ar8
ar9
0.3152 0.8762 -0.4413 0.0152 0.1500 0.0001 -0.0413 -0.1811
2007 Aug 31
3
Choosing the optimum lag order of ARIMA model
Dear all R users,
I am really struggling to determine the most appropriate lag order of ARIMA model. My understanding is that, as for MA [q] model the auto correlation coeff vanishes after q lag, it says the MA order of a ARIMA model, and for a AR[p] model partial autocorrelation vanishes after p lags it helps to determine the AR lag. And most appropriate model choosed by this argument gives
2006 Nov 07
1
Comparison between GARCH and ARMA
Dear all R user,
Please forgive me if my problem is too simple.
Actually my problem is basically Statistical rather
directly R related. Suppose I have return series ret
with mean zero. And I want to fit a Garch(1,1)
on this.
my is r[t] = h[i]*z[t]
h[t] = w + alpha*r[t-1]^2 + beta*h[t-1]
I want to estimate the three parameters here;
the R syntax is as follows:
#
2000 Nov 30
1
means in arima0 (PR#754)
Full_Name: Arto Luoma
Version: 1.1.0
OS: Windows 98
Submission from: (NULL) (153.1.53.119)
In arima0 it is possible to specify whether the mean of the original series is
included in the model or not. However, it is not possible to specify whether the
mean of the differenced series is included. It seems that it is not included.
However, if differencing is used to eliminate trend, the mean of the
2003 May 16
3
ARMA.predict?
Hi there,
Does anyone know how to predict ARMA? It doesn?t have either predict or forecast methods. I found couple of packages called fbasic and fseries at http://www.itp.phys.ethz.ch/econophysics/R/, which has ?arma.predict? in it, but it doesn?t seem to be working. Any help in this regard would be appreciated. Thanks in advance.
Regards
Skanda Kallur
"Prediction is very difficult,
2003 Dec 18
1
Help with predict.Arima with external regressor values [Repalced]
Hi all there
I am enjoying R since 2 weeks and I come to my first deadlock, il am trying
to use predict.Arima in the ts package.
I get a "Error in cbind(...) : cannot create a matrix from these types"
-- Start R session -----------------------------------------------------
> fitdiv <- arima(data, c(2, 0, 3), xreg = y ) ; print(fitdiv)
Call:
arima(x = data, order = c(2, 0, 3),
2002 Apr 03
1
arima0 with unusual poly
Dear R People:
Suppose I want to estimate the parameters of the
following AR model:
(1 - phi_1 B - phi_2 B^2 - phi_9 B^9) x_t = a_t
and I want to use the arima0 command from the
ts library.
How would I use the order subcommand, please?
R Version 1.4.1 for Windows.
Thanks!
Sincerely,
Erin Hodgess
Associate Professor
Department of Computer and Mathematical Sciences
University of Houston -
2017 Jun 20
1
How to write an estimated seasonal ARIMA model from R output?
I'm trying to use the following command.
arima (x, order = c(p,d,q), seasonal =list(order=c(P,D,Q), period=s)
How can I write an estimated seasonal ARIMA model from the outputs. To be specifically, which sign to use? I know R uses a different signs from S plus.
Is it correct that the model is:
(1-ar1*B-ar2*B^2-...)(1-sar1*B^s-sar2*B^2s-....)(1-B)^d(1-B^s)^D
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
2009 Jan 23
1
forecasting error?
Hello everybody!
I have an ARIMA model for a time series. This model was obtained through an
auto.arima function. The resulting model is a ARIMA(2,1,4)(2,0,1)[12] with
drift (my time series has monthly data). Then I perform a 12-step ahead
forecast to the cited model... so far so good... but when I look the plot of
my forecast I see that the result is really far from the behavior of my time
2010 Aug 21
1
How to find residual in predict ARIMA
Dear All,
I have a model to predict time series data for example:
data(LakeHuron)
Lake.fit <- arima(LakeHuron,order=c(1,0,1))
then the function predict() can be used for predicting future data
with the model:
LakeH.pred <- predict(Lake.fit,n.ahead=5)
I can see the result LakeH.pred$pred and LakeH.pred$se but I did not
see residual in predict function.
If I have a model:
[\
Z_t =
2009 Feb 03
3
Problem about SARMA model forcasting
Hello, Guys:
I'm from China, my English is poor and I'm new to R. The first message I sent to R help meets some problems, so I send again.
Hope that I can get useful suggestions from you warm-hearted guys.
Thanks.
I builded a multiplicative seasonal ARMA model to a series named "cDownRange".
And the order is (1,1)*(0,1)45
The regular AR=1; regular MA=1; seasonal AR=0; seasonal