Displaying 20 results from an estimated 10000 matches similar to: "auto.arima help"
2011 Jun 15
1
Query regarding auto arima
I am using AUTO ARIMA for forecasting. But it is not detecting 'seasonality
term' of its own for any data.
Is there any other method by which we can detect seasonality and its
frequency for any data?
Is there any method through which seasonality and its frequency can be
automatically detected from ACF plot?
--
Siddharth Arun,
4th Year Undergraduate student
Industrial Engineering and
2011 Jun 15
1
Problem auto.arima() in R
I am using auto.arima() for forecasting.When I am using any in built data
such as "AirPassangers" it is capturing seasonality. But, If I am entering
data in any other format(in vector form or from an excel sheet) it is not
detecting seasonality.
Is there any specific format in which it detects seasonality or I am doing
some thing wrong?
Does data have to be entered in a specific
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
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 (!).
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
2010 Mar 17
1
Reg GARCH+ARIMA
Hi,
Although my doubt is pretty,as i m not from stats background i am not sure
how to proceed on this.
Currently i am doing a forecasting.I used ARIMA to forecast and time series
was volatile i used garchFit for residuals.
How to use the output of Garch to correct the forecasted values from ARIMA.
Here is my code:
###delta is the data
fit<-arima(delta,order=c(2,,0,1))
fit.res <-
2006 Oct 19
1
predict.Arima question
Hi,
I am trying to forecast a model using predict.Arima
I found arima model for a data set: x={x1,x2,x3,...,x(t)}
arima_model = arima(x,order=c(1,0,1))
I am forecasting the next N lags using predict:
arima_pred = predict(arima_model,n.ahead = N, se.fit=T)
If I have one more point in my series, let's say x(t+1). I do not want to
recalibrate themodel, I just want to forecast the next N-1
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
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
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),
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
2007 Nov 08
1
Help me please...Large execution time in auto.arima() function
Hello,
I using the fuction auto.arima() from package forecast to predict the values
of p,d,q and P,D,Q.
My problem is the execution time of this function, for example, a time
series with 2323 values with seasonality to the week take over 8 hours to
execute all the possibilities.
I using a computer with Windows XP, a processor Intel Core2 Duo T7300 and
2Gb of RAM.
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
2011 Feb 27
2
finding model order components for arima()
Greetings,
I am trying to model a time series using arima(). For getting the
model order components(p, d, q and P,D,Q) I am using procedure
discussed in [1] in section 3.2 . It is most likely hit and trial
method based on lower AIC value.
I want to know what is the correct way to find model order components
or the method described in [1] is the appropriate one.
thanks in advance.
--
[1]Automatic
2007 Dec 01
1
modeling time series with ARIMA
Good afternoon!
I'm trying to model a time series on the following data, which represent a monthly consumption of juices:
>x<-scan()
1: 2859 3613 3930 5193 4523 3226 4280 3436 3235 3379 3517 6022
13: 4465 4604 5441 6575 6092 6607 6390 6150 6488 5912 6228 10196
25: 7612 7270 8617 9535 8449 8520 9148 8077 7824 7991 7660 12130
37: 9135 9512 9631 12642
2009 Oct 27
3
Non-normal residuals.
Hello,
I asked a question about what the most likely process to follow if after a time-series fit is performed the residuals are found to be non-normal. One peron responded and offered to help if I supplied a sample data set. Unfortunately now that I have a sample I have lost the emai addressl. If you are that person or have some ideas please email me back at rkevinburton at charter.net.
Thank
2008 May 08
1
ARIMA, AR, STEP
Here is my problem:
Autoregressive models are very interesting in forecasting consumptions (eg water, gas etc).
Generally time series of this type have a long history with relatively simple patterns and can be useful to add external regressors for calendar events (holydays, vacations etc).
arima() is a very powerful function but kalman filter is very slow (and I foun difficulties of estimation)
2012 Mar 08
1
ADL in auto.arima [SEC=UNOFFICIAL]
Hi,
I am trying to run ADL model by using auto.arima in package "forecast".
I put two time series,x and xreg, in the formula, but got message: Error
in nsdiffs(xx) : Non seasonal data. Any one can tell how to use it?
Thanks
Richard
***************************************************************************************************
IMPORTANT:
* This transmission is intended for the
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
2005 Jul 08
1
help with ARIMA and predict
I'm trying to do the following out of sample
regression with autoregressive terms and additional x
variables:
y(t+1)=const+B(L)*y(t)+C(1)*x_1(t)...+C(K)*x_K(t)
where:
B(L) = lag polynom. for AR terms
C(1..K) = are the coeffs. on K exogenous variables
that have only 1 lag
Question 1:
-----------
Suppose I use arima to fit the model: