Displaying 20 results from an estimated 40000 matches similar to: "arima function fix the coefficients"
2009 Jun 04
2
Import ARIMA coefficients
Hello,
I need to know how to import ARIMA coefficients. I already determined the coefficients of the model with other software, but now i need to do the forecast in R.
For Example: I have a time series named x
and i have fitted an ARIMA(1,0,1) (with other software)
AR coef = -.172295
MA coef = .960043
(i know that this is not a good model, it's just an example)
I try to
2011 Jul 07
3
AR vs ARIMA question
Dear R People:
Here is some output from AR and ARIMA functions:
> xb <- arima.sim(n=120,model=list(ar=0.85))
> xb.ar <- ar(xb)
> xb.ar
Call:
ar(x = xb)
Coefficients:
1
0.6642
Order selected 1 sigma^2 estimated as 1.094
> xb.arima <- arima(xb,order=c(1,0,0),include.mean=FALSE)
> xb.arima
Call:
arima(x = xb, order = c(1, 0, 0), include.mean = FALSE)
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)
2009 Jun 05
1
Bug in print.Arima and patch
Dear List,
A posting to R-Help exposed this problem with the print method for
objects of class Arima:
> set.seed(1)
> x <- arima.sim(n = 100, list(ar = 0.8897, ma = -0.2279))
> mod <- arima(x, order = c(1,0,1))
> coefs <- coef(mod)
> mod2 <- arima(x, order = c(1,0,1), fixed = coefs)
> mod2
Call:
arima(x = x, order = c(1, 0, 1), fixed = coefs)
Coefficients:
Error
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?
>
2004 Jan 14
2
Fixed parameters in an AR (or arima) model
Hello
I want to fit an AR model were two of the coefficients are fixed to zero
(the second and third ar-coefficients).
I used the "arima" function with the "fixed" argument but the ar3
coefficient is not set to zero:
==============================================
> arima(Y, order=c(4,0,0), xreg=1:23, fixed=c(NA,0,0,NA,NA,NA))
Call:
arima(x = Y, order = c(4, 0, 0), xreg =
2008 Sep 10
0
MA coefficients
Hi everyone,
I am performing the time series regression analysis on a series of data sets. A few data sets followed an ARMA(1,1) process. However, they all had a same value of moving average MA coefficients = -1, constantly, from output of function “arima" .
Example:
> arima(residuals, order=c(1,0,1))
Call:
arima(residuals, order = c(1, 0, 1))
Coefficients:
ar1 ma1 intercept
2010 Mar 25
1
*** caught segfault *** address 0x18, cause 'memory not mapped'
Hello R Community,
I've been run the following codes. However, I've been getting an
unusual segfault
that I'm unable to trace its origin. Please give me a light to
decipher the "caught segfault"
Thanks for you attention.
Bernardo.
> options(STERM='iESS', editor='emacsclient')
> rm(list = ls())
> > source("fgenIGLD.R") #RNG
2011 Sep 12
1
Difference in function arima estimation between 2.11.1 and R 2.12.2
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
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 Mar 11
1
messages from mle function
Dears useRs,
I am using the mle function but this gives me the follow erros that I
don't understand. Perhaps there is someone that can help me.
thank you for you atention.
Bernardo.
> erizo <- read.csv("Datos_Stokes_1.csv", header = TRUE)
> head(erizo)
EDAD TALLA
1 0 7.7
2 1 14.5
3 1 16.9
4 1 13.2
5 1 24.4
6 1 22.5
> TAN <-
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
2008 Apr 17
1
How to extract vectors from an arima() object and into a data frame?
This should be very easy, but alas, I'm very new to R. My end goal is to
calculate p-values from arima().
Let's say I just ran this:
> MyModel <- arima(y[1:58], order=c(1,0,0), xreg=MyData[1:58,7:14],
> method="ML")
> MyModel
And I see:
arima(x = y[1:58], order = c(1, 0, 0), xreg = MyData[1:58, 7:14], method =
"ML")
Coefficients:
ar1
2013 Jun 07
1
arima time series in R
Hi
Could just anyone explain me the coefficients in the output of arima model
timeseriesarima <- arima(series, order=c(1,1,2))
> timeseriesarima
Series: series
ARIMA(1,1,2)
Coefficients:
ar1 ma1 ma2
0.9744 -1.7695 0.7873
s.e. 0.0310 0.0481 0.0426
sigma^2 estimated as 337.4: log likelihood=-1096.03
AIC=2200.07 AICc=2200.23 BIC=2214.2
****************
2002 Sep 23
0
arima() in package ts.
I've been trying to get comfy with arima() and associated functions
in the ts() package. I'm thinking seriously about using this
package, and R generally, in a 4th year intro time series course that
I'm teaching this autumn.
I have a couple of questions about arima:
(1) The help file says that residuals component of the value returned
by arima() consists of the
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
2023 Jan 05
1
R 'arima' discrepancies
Rob J Hyndman gives great explanation here
(https://robjhyndman.com/hyndsight/estimation/) for reasons why results
from R's arima may differ from other softwares.
@iacobus, to cite one, 'Major discrepancies between R and Stata for
ARIMA'
(https://stackoverflow.com/questions/22443395/major-discrepancies-between-r-and-stata-for-arima),
assign the, sometimes, big diferences from R
2007 Dec 21
1
matrix to gal object
useR's
I need transform the matrix
wdat
[,1] [,2] [,3] [,4] [,5] [,6]
[1,] 0 1 0 1 1 0
[2,] 1 0 0 1 1 0
[3,] 0 0 0 0 1 1
[4,] 1 1 0 0 1 0
[5,] 1 1 1 1 0 0
[6,] 0 0 1 0 0 0
to gal object. How I do with spdep?
Thanks in advance for the help.
Bernardo.
University of Concepci?.
2009 Jun 03
0
Import ARIMA-GARCH coefficients
Hello,
I am modelling a Time Serie with ARIMA-GARCH and i have already determined the coefficients ( ARIMA and GARCH) with other software. Now I am trying to do the forecast in R, but i don't know how i can import the coefficients.
I will be very pleased if someone help me.
Daniel
_________________________________________________________________
Mais do que mensagens – conheça
2012 Apr 17
2
Manually reconstructing arima model from coefficients
Colleagues
I am a new to R but already love it.
I have the following problem:
I fitted arima model to my time series like this (please ignore modeling
parameters as they are not important now):
x = scan("C:/data.txt")
x = ts(x, start=1, frequency=1)
x.fit<-arima(x, order = c(1,0,0), seasonal = list(order=c(0,0,1)))
Now I want to use this model for forecasting and backtesting (!).