Displaying 20 results from an estimated 7000 matches similar to: "Search for best ARIMA model"
2006 Jul 26
3
Moving Average
Dear R-Users,
How can I compute simple moving averages from a time series in R?
Note that I do not want to estimate a MA model, just compute the MA's
given a lenght (as excel does).
Thanks
________________________________________
Ricardo Gonçalves Silva, M. Sc.
Apoio aos Processos de Modelagem Matemática
Econometria & Inadimplência
Serasa S.A.
(11) - 6847-8889
ricardosilva@serasa.com.br
2003 Feb 13
2
ROC
Hi, can you advise me is there any ROC(Receiver
Operating Characteristic)analysis program in R?
Thanks,
Dechao
=====
Dechao Wang
Tel: (44) 01223 719718
Mob: (44) 07729 411134
__________________________________________________
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from News and Sport to Email and Music Charts
2006 Jul 26
1
arima() function - issues
Hi,
My query is related to ARIMA function in stats package.
While looking for the time series literature I found following link which
highlights discrepancy in "arima" function while dealing with
differenced time series. Is there a substitute function similar to
"sarima" mentioned in the following website implemened in R? Any pointers would
be of great help.
2004 Jul 01
2
[gently off topic] arima seasonal question
Hello R People:
When using the arima function with the seasonal option, are the seasonal
options only good for monthly and quarterly data, please?
Also, I believe that weekly and daily data are not appropriate for seasonal
parm estimation via arima.
Is that correct, please?
Thanks,
Sincerely,
Laura Holt
mailto: lauraholt_983 at hotmail.com
download!
2003 Mar 04
3
linear model with arma errors
Dear all,
I'm looking for how can I estimate a linear model with ar(ma) errors :
y(t)=a*X(t)+e(t) with
P(B)e(t)=Q(B)u(t)
where u is a white noise and P, Q are some polynomes.
Could you help me ?
Gr?gory Benmenzer
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?
>
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
2005 Nov 28
1
AIC and BIC from arima()
-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1
My ultimate goal is to best fit time series by comparing AICs and BICs
(as in Bayesian) from arima() and nnet().
I looked at the arima.R source code, but I am afraid I do not
understand it.
What I only miss really is the number of parameters p, where: AIC =
n*log(S/n) + 2*p
with S the squared residuals and n the number of observations.
Can I get p
2010 Nov 22
2
Help: Standard errors arima
Hello,
I'm an R newbie. I've tried to search, but my search skills don't seem
up to finding what I need. (Maybe I don't know the correct terms?)
I need the standard errors and not the confidence intervals from an
ARIMA fit.
I can get fits:
> coef(test)
ar1 ma1
intercept time(TempVector) - 1900
2007 Dec 11
1
question regarding arima function and predicted values
Good evening!
I have a question regarding forecast package and time series analysis.
My syntax:
x<-c(253, 252, 275, 275, 272, 254, 272, 252, 249, 300, 244, 258, 255, 285, 301, 278, 279, 304, 275, 276, 313, 292, 302, 322, 281, 298, 305, 295, 286, 327, 286, 270, 289, 293, 287, 267, 267, 288, 304, 273, 264, 254, 263, 265, 278)
library(forecast)
arima(x, order=c(1,1,2),
2011 Jul 04
1
forecast: bias in sampling from seasonal Arima model?
Dear all,
I stumbled upon what appears to be a troublesome issue when sampling from an
ARIMA model (from Rob Hyndman's excellent 'forecast' package) that contains
a seasonal AR component.
Here's how to reproduce the issue. (I'm using R 2.9.2 with forecast 2.19;
see sessionInfo() below).
First some data:
> x <- c(
0.132475, 0.143119, 0.108104, 0.247291, 0.029510,
2004 Jan 14
1
seasonal fractional ARIMA models
Hello,
does anyone know about:
a) simulating seasonal ARIMA models? arima out of package ts can fit it,
but it does not look like it can simulates data from seasonal models
b) fitting and simulating fractional seasonal ARIMA models?
Hints will be appreciated,
Henning
--
Henning Rust
Potsdam Institute for Climate Impact Research
Dept. Integrated Systems Analysis
Tel.: #49/331/288-2596
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
2013 Sep 09
1
Fitting Arima Models and Forecasting Using Daily Historical Data
Hello everyone,
I was trying to fit an arima model to a daily historical data, but, for
some reason, havent been able to.
I basically have 212 observations (from 12/1/2012 to 06/30/2013) containing
the number of transits for a particular vessel.
The following messages are produced by R:
dailytrans.fit<-arima(dailytrans$transits, order=c(0,1,2),
seasonal=list(order=c(0,1,2), period=365),
2003 Apr 07
1
filtering ts with arima
Hi,
I have the following code from Splus that I'd like to migrate to R. So far,
the only problem is the arima.filt function. This function allows me to
filter an existing time-series through a previously estimated arima model,
and obtain the residuals for further use. Here's the Splus code:
# x is the estimation time series, new.infl is a timeseries that contains
new information
# a.mle
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
2015 Apr 20
2
Fix for bug in arima function
There is currently a bug in the arima function. Namely, for arima models with differencing or seasonal differencing, the innovation variance estimator uses the wrong denominator whenever xreg is non-null. This is the case, for example, when fitting an ARIMA(p,1,q) model with a drift term (common in financial applications). I reported the bug (and a fix) at
2015 May 21
2
Fix for bug in arima function
On 21 May 2015, at 10:35 , Martin Maechler <maechler at lynne.stat.math.ethz.ch> wrote:
>>
>> I noticed that the 3.2.1 release cycle is about to start. Is there any
>> chance that this fix will make it into the next version of R?
>>
>> This bug is fairly serious: getting the wrong variance estimate leads to
>> the wrong log-likelihood and the wrong
2011 Dec 28
2
Census ARIMA x-12 seasonal adjustment in R?
Hello,
I am new to usin R - which is a great tool - and would like to know if R
has a seasonal adjustment program for time series and/if it incorporates
the Census Bureau's ARIMA x-12 seasonal adjustment program in any way?
Thanks so much!
Tony
[[alternative HTML version deleted]]
2011 Oct 21
2
Arima Models - Error and jump error
Hi people,
I´m trying to development a simple routine to run many Arima models result
from some parâmeters combination.
My data test have one year and daily level.
A part of routine is:
for ( d in 0:1 )
{ for ( p in 0:3 )
{ for ( q in 0:3 )
{ for ( sd in 0:1 )
{ for ( sp in 0:3 )
{ for ( sq in 0:3 )
{