Displaying 20 results from an estimated 3000 matches similar to: "predict.Arima question"
2008 Aug 12
1
arima forecast function
hi:
I am trying to fit prediction intervals for an arima object. My search led
me to the link:
http://finzi.psych.upenn.edu/R/library/forecast/html/forecast.Arima.html
which has the function "forecast", as I wanted. However, when I try to run
it in R, I get the message:
Error in plot(forecast(fit)) : could not find function "forecast"
Even the example provided on the page
2010 Mar 19
1
Arima forecasting
Hello everyone,
I'm doing some benchmark comparing Arima [1] and SVR on time series data.
I'm using an out-of-sample one-step-ahead prediction from Arima using
the "fitted" method [2].
Do someone know how to have a two-steps-ahead forecast timeseries from Arima?
Thanks,
Matteo Bertini
[1] http://robjhyndman.com/software/forecast
[2] AirPassengers example on page 5
2010 Oct 07
1
auto.arima error
I am trying to use auto.arima to fit a univariate time series and do forecast.
This is an imaginary data on monthly outcomes of 2 years and I want to forecast the outcome for next 12 months of next year.
data Data1;
input RR;
datalines;
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;
run;
I successfully took this data into R and used the auto.arima codes but am getting
2009 Mar 05
3
Time Series - ARIMA differencing problem
Hi,
I have been using this website (
http://www.stat.pitt.edu/stoffer/tsa2/Rissues.htm
http://www.stat.pitt.edu/stoffer/tsa2/Rissues.htm ) to help me to fit ARIMA
models to my data. At the moment I have two possible methods to use.
Method 1
If I use
arima(ts.data, order=c(1,2,0), xreg=1:length(ts.data))
then the wrong value for the intercept/mean is given (checked on SPSS and
Minitab) and
2003 Apr 21
2
Anyone Familiar with Using arima function with exogenous variables?
I've posted this before but have not been able to locate what I'm doing
wrong. I cannot determine how the forecast is made using the estimated
coefficients from a simple AR(2) model when there is an exogenous
variable. Does anyone know what the problem is? The help file for arima
doesn't show the model with any exogenous variables. I haven't been able
to locate any documents
2008 Jul 29
0
handling multiple lookup tables in rails
I''ve got an application that will have a handful of lookup tables. To
be clear by this I mean tables that only have two attributes, id, name
and are used to provide drop-down lists for other tables/forms so that
these fields have "standard" values. I need 5 to 10 of these tables.
I''m a ruby/rails neophyte but I''ve read Agile Web Devel with
Rails, Rails
2012 Apr 26
1
Using the R predict function to forecast a model fit with auto.arima function
Hello R users,
Hope everyone is doing great.
I have a dataset that is in .csv format and consists of two columns: one
named Period (which contains dates in the format yyyy_mm) and goes from
1995_10 to 2007_09 and the second column named pcumsdry which is a
volumetric measure and has been formatted as numeric without any commas or
decimals.
I imported the dataset as pauldataset and made use of
2009 Jan 18
1
auto.arima forecasting issue
Hello everybody!
I'm having this problem with the auto.arima function that i've not been
able to solve. I use this function on time series that contains NA values,
but every time that the resulting model contains drift I can't perform a
forecasting (using forecast.Arima function). The printed error (when I try
to forecast the resulting model) claims a dimension mismatch
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 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,
2012 Jan 04
1
[Matlab] Need help on ARIMA and Matlab
Hi, I have to forecast some value of a time series using an ARIMA(5,1,3)
model.
I saw in Matlab there isn't a function for ARIMA models because ARIMA
models are a type of Box-Jenkins models. But how to set parameters?
In the Box-Jenkins models
m = bj(data,[nb nc nd nf nk])
How to set nb, nc, nd, nf and nk in order to have an ARIMA(p,d,q) model?
Thanks
[[alternative HTML version
2006 Nov 25
2
predict and arima
Hi all,
Forecasting from an arima model is easy with predict.
But I can't manage to backcast : invent data from the model before the
begining of the sample.
The theory is easy : take your parameters, reverse your data, forecast, and
then reverse the forecast
I've tried to adapt the predict function to do that (i'm not sure that the
statistical procedure is fine (with the residuals),
2012 Sep 10
2
predict arima
Hello, I have a question regarding the predict command for ARIMA models. Why do I not have to give any input except the number of steps for the forecast? Which input value is used (in my case for “y(t)”)? Will the last parameter of the estimate vector be used (in my example “6”)? x <- c(1,2,3,4,5,6)model <- arima(x, order=c(1,0,0), method="ML")predict(model, n.ahead = 1) ->
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
2010 Apr 29
1
forecast in arima
Hello,
I have a question about forecast under model arima(1,1,1).
I construct this model on 1000 observations and find the forecast for
following, for example, 100 observations.
But it' s necessary for me to get the predicted values of the previous 100
observations and compare it with actual values.
Please, tell me what should be done.
Thank you very much
[[alternative HTML version
2004 Sep 03
2
arima et graphique
bonjour, je rencontre quelques soucis au niveau de l'utilisation des
fonctions arima.forecast/predict; en effet elles sont dites inconnues alors
que j'ai bien install?? et charg?? le package "ts". Aussi, j'aimerai savoir
comment visualiser le graphique des pr??visions avec arima et celui des
donn??es brutes dans la m??me fen??tre.
Tout en vous souhaitant bonne r??ception
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),
2013 Apr 15
1
use of simulate.Arima (forecast package)
I would like to simulate some SARIMA models, e.g. a SARIMA (1,0,1)(1,0,1)[4] process.
I installed the package 'forecast', where the function simulate.Arima should do what I am trying to do.
I am not able to understand how it works
Could somebody help me with an example?
thank you
Stefano Sofia
AVVISO IMPORTANTE: Questo messaggio di posta elettronica pu? contenere informazioni
2012 Aug 01
1
Odd Results when using R's auto.arima function
Good morning everyone,
I have attached an Excel file that contains a macro from which I call and
use R's auto.arima function to generate forecasts. The program runs
perfectly and it gets me the results; however, those results are pretty
unusual. I also tried using the auto.arima function directly in the R
console and still get weird results.
The results are shown in columns AB, AC and AD
2016 Apr 07
4
Contenido de un objeto/modelo ARIMA
Buenos días,
Os cuento:
Cargo la librería "Forecast" y ejecuto su función Arima(...) sobre una
serie temporal:
mimodelo <- Arima(miST$miserie, ...);
Ahora si ejecuto las siguientes sentencias, voy obteniendo los resultados
contenidos en "mimodelo", pero algunos de ellos no sé lo que son:
mimodelo[[1]] obtengo los coeficientes del modelo ARIMA
mimodelo[[2]] obtengo el