Displaying 20 results from an estimated 333 matches for "arma".
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2005 Jun 14
1
using forecast() in dse2 with an ARMA model having a trend component
...9;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
arma.fit.input <- c(105.3332, 105.3573, 105.3113, 105.1493, 105.1209,
105.2111, 104.9161,
105.3654, 105.4682, 105.6789, 105.6297, 106.0155,
105.8454, 105.4322,
105.6062, 106.0739, 106.1109, 105.4470, 104.9739,
105.3427, 105.4305,...
2009 Mar 06
0
modifying a built in function from the stats package (fixing arima) (CONCLUSIONS)
Thanks a lot to everybody that helped me out with this.
Conclusions:
(1)
In order to edit arima in R:
>fix(arima)
or alternatively:
>arima<-edit(arima)
(2)
This is not contained in the "Introduction to R" manual.
(3)
A "productive" fix of arima is attached (arma coefficients printed out and
error catched so that it doesn't halt parent loops to search for candidate
coefficients):
Note 1: "productive" means I'm a beginner in R so there is probably a better
way to print the error message and fill the output arguments (I only return
NA in aic...
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
Sk...
2011 Dec 05
1
RcppArmadillo compilation error: R CMD SHLIB returns status 1
Dear all,
running the example by D. Eddebuettel (http://dirk.eddelbuettel.com/blog/2011/04/23/) I get an error message. Specifically, the R code I was taking from the above example is
### BEGIN EXAMPLE ###
suppressMessages(require(RcppArmadillo))
suppressMessages(require(Rcpp))
suppressMessages(require(inline))
code <- '
arma::mat coeff = Rcpp::as<arma::mat>(a);
arma::mat errors = Rcpp::as<arma::mat>(e);
int m = errors.n_rows; int n = errors.n_cols;
arma::mat simdata(m,n);
simdata.row(0) = arma::zero...
2009 Jul 15
2
storing lm() results and other objects in a list
...nthlyBLA,mcReg)
LinearModel1.res <- residuals(linearModel1)
LinearModel2.res <- residuals(linearModel2)
LinearModel3.res <- residuals(linearModel3)
LinearModel4.res <- residuals(linearModel4)
LinearModel5.res <- residuals(linearModel5)
#hmmm bolt on linearModel[x] as linearModel[x]$arma.fit?
arma1.fit <- auto.arima(LinearModel1.res)
arma2.fit <- auto.arima(LinearModel2.res)
arma3.fit <- auto.arima(LinearModel3.res)
arma4.fit <- auto.arima(LinearModel4.res)
arma5.fit <- auto.arima(LinearModel5.res,stepwise=T,trace=T)
#Ok what is left over after Regression and ARIMA...
2007 Oct 22
1
Newbie help: Data in an arma fit
I'd like to fit an ARMA(1,1) model to some data (Federal Reserve Bank
interest rates) that looks like:
...
30JUN2006, 5.05
03JUL2006, 5.25
04JUL2006, N <---- here!
05JUL2006, 5.25
...
One problem is that holidays have that "N" for their data. As a test, I
tried fitting ARMA(1,1) with...
2005 Dec 23
1
dse package problems
...#39;dse1'
The following object(s) are masked from package:stats :
acf simulate
> library("dse2")
>
> AR <- array(c(1, 0.5, 0.3, 0, 0.2, 0.1, 0, 0.2, 0.05, 1, 0.5, 0.3), c(3, 2,
+ 2))
> MA <- array(c(1, 0.2, 0, 0.1, 0, 0, 1, 0.3), c(2, 2, 2))
> arma <- ARMA(A = AR, B = MA, C = NULL)
> data.arma.sim <- simulate(arma)
>
> data.arma.sim
output data:
Error: evaluation nested too deeply: infinite recursion / options(expressions=)?
>
#############################################################
###############################...
2004 Oct 25
1
output processing / ARMA order identification
Dear R users,
I need to fit an ARMA model. As far as I've seen, EACF (extended ACF)
is not available in R.
1. Let's say I fit a series of ARMA models in a loop. Given the
code/output included below, how do I pull 'Model' and 'Fit' (AIC)
from each summary() so that I can combine them into an array/data
frame...
2009 Oct 22
1
arima crashes too
Another pathological test.
arima does not crash for that series that crashes arma:
arima(c(2.01, 2.22, 2.09, 2.17, 2.42), order=c(1,0,0))
However, arima crashes for this:
arima(c(1.71, 1.78, 1.95, 1.59, 2.13), order=c(1,0,0))
arima seems pretty consistent in its crashing behaviour, since crashing for
one series means crashing for all affine series:
lets.crash.arima <- c...
2006 Nov 07
1
Comparison between GARCH and ARMA
...) on this:
library(tseries)
garch(r)
The estimated parameters are given below:
***** ESTIMATION WITH ANALYTICAL GRADIENT *****
Call:
garch(x = r)
Coefficient(s):
a0 a1 b1
4.746e-06 6.837e-02 8.877e-01
Now it is straightforward to transform Garch(1,1)
to a ARMA like this:
r[t]^2 = w + (alpha+beta)*r[t-1]^2 + beta*(h[t-1] -
r[t-1]^2) - (h[t] - r[t]^2)
= w + (alpha+beta)*r[t-1]^2 + beta*theta[t-1] +
theta[t]
So if I fit a ARMA(1,1) on r[t]^2 I am getting
following result;
arma(r^2, order=c(1,1))
Call:
arma(x = r^2, order = c(1, 1))
Coeffic...
2008 Aug 20
2
arma: what is the meaning of Pr(>|t|)?
In the summary of the output of arma, there's a number Pr(>|t|), however, I
don't know what is its meaning - at least, it doesn't _seem_ to be a
Student's t distribution.
Reproducible test case:
x <- c(0.5, sin(1:9))
reg <- arma(x, c(1,0))
summary(reg)
<output>
Call:
arma(x = x, order = c(1, 0)...
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 i...
1999 Nov 14
1
bug in arma.sim (PR#322)
Dear Sir,
I think I found a bug in the function arma.sim, which is defined in
the help page of the function filter:
arma.sim <- function(n, ar = NULL, ma = NULL, sigma = 1.0)
{
x <- ts(rnorm(n+100, 0, sigma^2), start = -99)
if(length(ma)) x <- filter(x, ma, sides=1)
if(length(ar)) x <- filter(x, ar, method="recursive&quo...
2009 Apr 29
1
arma model with garch errors
Dear R experts,
I am trying to estimate an ARMA 2,2 model with garch errors.
I used the following code on R 2.9.
#library
library(fGarch)
#data
data1<-ts(read.table("C:/Users/falcon/Desktop/Time
Series/exports/goods1.csv"), start=c(1992,1), frequency=12)
head(data1)
#garch
garchFit(formula.mean= ~arma(2,2),formula.var=~garch(1,1),...
2011 May 08
1
ARMA
Hello,Could somebody tell me what is the difference between theese 3 calls of functionsarma(x,order=c(1,0)), arima(x,order=c(1,0,0)) ar(x,order=1)?I expected same residuals of theese three models,but unexpectably for the first two R requiredinitial value of something (what?)...Thanks in advance!
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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....
2006 Aug 14
1
ARMA(1,1) for panel data
Dear List,
I am new to TS-Modeling in R. I would like to fit an ARMA(1,1) model
for a balanced panel, running Y on a full set of unit and year dummies
using an arma(1,1) for the disturbance:
y_it=unit.dummies+yeardummies+e_it
where: e_it=d*e_it-1+u_it+q*u_it-1
How can I fit this model in R? arma() does not seem to take covariates
(or I don't understand how to...
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=lis...
2010 Aug 23
1
Fitting a regression model with with ARMA error
Hi,
I want to fit a regression model with one independent variable. The error
part should be fitted an ARMA process.
For example,
y_t = a + b*x_t + e_t where e_t is modelled as an ARMA process.
Please let me know how do I do this in R. What code should I use?
TIA
Aditya
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2013 Apr 08
0
Maximum likelihood estimation of ARMA(1,1)-GARCH(1,1)
Hello
Following some standard textbooks on ARMA(1,1)-GARCH(1,1) (e.g. Ruey
Tsay's Analysis of Financial Time Series), I try to write an R program
to estimate the key parameters of an ARMA(1,1)-GARCH(1,1) model for
Intel's stock returns. For some random reason, I cannot decipher what
is wrong with my R program. The R package fGarch alread...