Displaying 20 results from an estimated 900 matches similar to: "Help with arima.sim"
2014 Dec 12
2
Fwd: Fwd: Fwd: Fwd: Fwd: Fwd: Fwd: Fwd: 26.
Anna Crepes: Traubenzucker
+ Feldsalat spezielles Dressing (bringt selbst mit?)
-------- Weitergeleitete Nachricht --------
Betreff: Fwd: Fwd: Fwd: Fwd: Fwd: Fwd: Fwd: 26.
Datum: Thu, 11 Dec 2014 15:34:39 +0100
Von: Markus <universe at truemetal.org>
An: universe at truemetal.org
Geschenke Moritz: dunkle Schokolade.
Geschenke Anna: normale Schokolade.
-------- Weitergeleitete
2012 Sep 29
1
Problems with stepAIC
Dear help community,
I'm a R-beginner and use it for my master thesis.
I've got a mixed model and want to analyse it with lme. There are a lot
Cofactors that coult be relevant. To extract the important ones I want to do
the stepAIC, but always get an error warning.
Structure of my data:
data.frame': 72 obs. of 54 variables:
$ Block : Factor w/ 3 levels
2009 Sep 29
0
Incoherence between arima.sim and auto.arima
Hello,
I have a question about function arima.sim
I tried to somulate a AR(1) process, with no innovation, no error term.
I used this code:
library(forecast)
e=rnorm(100,mean=0,sd=0)
series=arima.sim(model=list(ar=0.75),n=100,innov=e)+20
Then I tried to applicate ti this series auto.arima function:
mod1<-auto.arima(series,stepwise=FALSE,trace=TRUE,ic='aicc')
The best model returned
2009 Jul 21
0
Specifying initial values for arima.sim
Hi Everyone,
I'm having a problem with arima.sim. Namely specifying inital values
for the series.
If I generate a random walk
> vs = rnorm(100,0,1)
> xs = cumsum(vs)
and fit an ARIMA(1,0,0) to it
> xarima = arima(xs,order=c(1,0,0))
> xarima
Call:
arima(x = xs, order = c(1, 0, 0))
Coefficients:
ar1 intercept
0.9895 8.6341
s.e. 0.0106 6.1869
I should
2009 Jan 20
0
arima.sim help
I am trying to simulate time series data for an ar(1) and ma(1) process. I want the error term to have either a t distribution with 1 degree of freedom or a normal distribution with mean=0 and sd=1. Here is my code:
error.model=function(n){rnorm(n,mean=0, sd=1)}
data<-arima.sim(model=list(ar=c(0.1)), n=1000,
n.start=200, start.innov=rnorm(200,mean=0, sd=1),
rand.gen=error.model )
data
2007 Jan 01
0
arima.sim with a periodic model
Hi all.
I have a periodiv arma model and I want to simulate it. In S-plus, the
following works for me:
phi <- 0.9
theta <- 0
p <- 1 # period
model <- list(ar=phi, ma=theta, period=p)
Yt <- arima.sim(model, n=250)
How do I do something like this "period=12" in R? I read help(arima.sim)
but it doesn't tell.
Thanks! Philip.
2009 Apr 05
0
Question about arima.sim()
Hi,
I tried to simulate an ARIMA model by using arima.sim(), say arima.sim(n=100,list(order=c(1,0,1),ar=0.6,ma=0.9,sd=1), but the acf and pacf of simulated data using acf() and pacf() are so much different from the theoritcal acf and pacf. For instance, in my case, ar=0.6 and ma=0.9, so the acf for all lags should be greater than 0 based on the theoritical calculation, but the acf of simulated
2010 Aug 19
1
How to include trend (drift term) in arima.sim
I have been trying to simulate from a time series with trend but I don't see
how to include the trend in the arima.sim() call. The following code
illustrates the problem:
# Begin demonstration program
x <- c(0.168766559, 0.186874000, 0.156710548, 0.151809531, 0.144638812,
0.142106888, 0.140961714, 0.134054659, 0.138722419, 0.134037018,
0.122829846, 0.120188714,
2011 Nov 22
1
arima.sim: innov querry
Apologies for thickness - I'm sure that this operates as documented and with good reason. However...
My understanding of arima.sim() is obviously imperfect. In the example below I assume that x1 and x2 are similar white noise processes with a mean of 5 and a standard deviation of 1. I thought x3 should be an AR1 process but still have a mean of 5 and a sd of 1. Why does x3 have a mean of ~7?
2003 Jul 16
1
arima.sim problems (PR#3495)
Full_Name: Gang Liang
Version: 1.7.1
OS: Debian/Woody
Submission from: (NULL) (192.6.19.190)
> print(arima.sim(list(ar=.3,order=c(1,1,1)), 30))
[1] 0.00000000 0.10734243 0.02907301 -1.23441659 -0.98819317 -2.82731975
[7] -2.69052512 -4.22884756 -5.02820635 -5.41514613 -6.20486350 -7.01040649
[13] -6.78121289 -5.41111810 -4.96338053 -5.42395408 -6.22741444 -5.75228153
[19] -6.07346580
2005 Oct 02
2
arima.sim bug?
Hi,
I am using the arima.sim function to generate some AR time series. However, the function does not seem to produce exactly the same time series when I specify the innov parameter. For example
> r <- rnorm(300)
> x <- arima.sim(300, model=list(order=c(1,0,0),ar=c(.96)), innov=r, n.start=10)
> y <- arima.sim(300, model=list(order=c(1,0,0),ar=c(.96)), innov=r, n.start=10)
>
2004 May 24
1
Null model for arima.sim().
In some time series simulations I'm doing, I occasionally want the
model to be ``white noise'', i.e. no model at all. I thought it
would be nice if I could fit this into the arima.sim() context,
without making an exceptional case. I.e. one ***could*** do
something to the effect
if(length(model)==0) x <- rnorm(n) else x <- arima.sim(model,n)
but it would be more suave if one
2005 Oct 10
1
using innov in arima.sim
Hello,
I have used the arima.sim function to generate a lot of time series, but to day I got som results that I didn't quite understand. Generating two time series z0 and z1 as
eps <- rnorm(n, sd=0.03)
z0 <- arima.sim(list(ar=c(0.9)), n=n, innov=eps)
and
z1 <- arima.sim(list(ar=c(0.9)), n=n, sd=0.03),
I would expect z0 and z1 to be qualitatively similar. However, with n=10 the
2000 Sep 22
2
arima.sim
Hi,
Before I re-invent the wheel, is there a function in R similar to S+'s
arima.sim, i.e., a function that simulates arima processes.
ts and tseries packages don't seem to have such function, but I may have
overlooked it.
Thank you for your time,
Alvaro Novo
R Version 1.1.1
SuSE 6.4 Linux
KDE 2.0 Beta 5
-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-
2012 Oct 08
1
arima.sim
Hi,
I have been using arima.sim from the stats package recently, and I'm
wondering why I get different results when using what seem to be the
same parameters. For example, I've given examples of three different
ways to run arima.sim with what I believe are the same parameters.
It's my understanding from the R documentation that rnorm is the
default function for rand.gen if not
2011 Mar 19
3
Sieve or not?
Hello,
I use V 2.11 and my question is:
Is one present Sieve with this version or
MUST this specially compiles?
# 2.0.11 (31d8d43fa6b5): /etc/dovecot/dovecot.conf
# OS: Linux 2.6.29.4 i686 Debian wheezy/sid
--
Mit freundlichen Gr??en,
Jim Knuth
P.S.: Bitte senden Sie KEINE HTML-Mails!
#####
Zufallszitat:
Der Fanatismus ist die einzige 'Willensst?rke',
zu der auch die Schwachen
2014 Dec 12
0
Fwd: Fwd: Fwd: Fwd: Fwd: Fwd: Fwd: Fwd: 26.
OMG.. how embarassing.. that was my personal reminder E-Mail for x-mas
dinner. Not meant for this list. Please ignore. Shame on me.. *blushing*
LOL.
Am 12.12.2014 um 21:19 schrieb Markus:
> Anna Crepes: Traubenzucker
> + Feldsalat spezielles Dressing (bringt selbst mit?)
>
>
>
> -------- Weitergeleitete Nachricht --------
> Betreff: Fwd: Fwd: Fwd: Fwd: Fwd: Fwd: Fwd: 26.
2011 Apr 21
3
R CMD Sweave versus Sweave() on Windows
Dear list subscriber,
I am quite puzzled by the behaviour of processing Sweave files within an R session, i.e.
Sweave("foo.Rnw") versus R CMD Sweave foo.Rnw
In the former the environmental variable 'SWEAVE_STYLEPATH_DEFAULT = TRUE' is obeyed (this is set in etc/Renviron.site as well as under the users home directory in .Renviron). That is the hard-coded path to Sweave.sty is
2009 Nov 11
1
Sweave() within a function: objects not found
Dear list subscriber,
suppose, I do have a minimal Sweave file 'test.Rnw':
\documentclass{article}
\begin{document}
<<printx>>=
x
@
\end{document}
Within R, I define the following function:
f <- function(x){
Sweave("test.Rnw")
}
The call:
f(x = 1:10)
results in the following error message:
> f(x = 1:10)
Writing to file test.tex
Processing code chunks
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