Displaying 20 results from an estimated 6000 matches similar to: "Interpolating / smoothing missing time series data"
2005 Aug 27
1
ARIMA (seasonal) backcasting & interpolation
Thanks for everyone's help with zoo -- I think I've got my data set
ready. (The data consists of surface weather temperatures, from 2002
to 2005, one observation per hour. Some values are missing... i.e. NA)
I have three goals:
GOAL #1:Get the data in proper time series form, preserving frequency
information:
> w4.ts <- as.ts( w3.zoo, frequency=(1/3600) )
I hope that 1/3600
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),
2011 Aug 30
2
ARMA show different result between eview and R
When I do ARMA(2,2) using one lag of LCPIH data
This is eview result
>
> *Dependent Variable: DLCPIH
> **Method: Least Squares
> **Date: 08/12/11 Time: 12:44
> **Sample (adjusted): 1970Q2 2010Q2
> **Included observations: 161 after adjustments
> **Convergence achieved after 14 iterations
> **MA Backcast: 1969Q4 1970Q1
> **
> **Variable Coefficient Std.
2007 Nov 26
3
Time Series Issues, Stationarity ..
Hello,
I am very new to R and Time Series. I need some help including R codes
about the following issues. I' ll really appreciate any number of
answers...
# I have a time series data composed of 24 values:
myinput = c(n1,n2...,n24);
# In order to make a forecasting a, I use the following codes
result1 = arima(ts(myinput),order = c(p,d,q),seasonal = list(order=c(P,D,Q)))
result2 =
2004 Jul 04
1
Re: Seasonal ARMA model
> It might clarify your thinking to note that a seasonal ARIMA model
> is just an ``ordinary'' ARIMA model with some coefficients
> constrained to be 0 in an efficient way. E.g. a seasonal AR(1) s =
> 4 model is the same as an ordinary (nonseasonal) AR(4) model with
> coefficients theta_1, theta_2, and theta_3 constrained to be 0. You
> can get the same answer as from
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
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),
2006 Aug 24
2
Search for best ARIMA model
Hello,
I have a several time series, which I would like to check for their best
fitted Arima model (I am checking for the lowest aic value).
Which lets me raise two questions:
1) is there are more efficient way, than using 6 for-loops?
2) sometimes the system cannot calculate with given parameters - is
there a more efficient solution than I found?
I hope, you can help me to make this
2009 Oct 13
1
How to specify an ARMA(1, [1,4]) model?
Hi,
I'm trying to model an ARMA(1,[1,4]),
i.e. I want only lags 1 and 4 of the Moving Average part.
It's the '[1,4]' part that is giving me a problem.
I've tried different arma's and arima's in different packages, namely:
packages tseries, fArma, FinTS, timeSeries, TSA, Zelig, ds1, forecast
For example, with package FinTS:
> ( ARIMA(y, order=c(1,0,c(1,4))) )
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!
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
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
2025 Jan 02
1
Possible issue in stats/arima.R package
>>>>> Duncan Murdoch
>>>>> on Thu, 2 Jan 2025 11:28:45 -0500 writes:
> On 2025-01-02 11:20 a.m., Duncan Murdoch wrote:
>> On 2025-01-02 9:04 a.m., Norbert Kuder wrote:
>>> Hello all,
>>>
>>> I am running R version 4.4.2 (2024-10-31 ucrt) on Windows 10 x64, and
>>> noticed something that might
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?
>
2005 Oct 04
2
Need help on ARIMA (time series analysis)
Hi,
I am so novice in using R. I have some problems in my R script below
which fits time series data and predict it one-step ahead. Here is a
brief explanation on what I try to achieve
Th16k is time series data (500 data points). The size of window for
fitting and predicting is 50 (data points). As you can easily discover
from my code, (fixed) window is moving/sliding to get next one-step
2010 Aug 30
1
How to Remove Autocorrelation from Simple Moving Average time series
Hi R experts,
I am trying to remove autocorrelation from Simple Moving Average time series. I know that this can be done by using seasonal ARIMA like,
library(TTR)
data <- rnorm(252)
n=21
sma_data=SMA(data,n)
sma_data=sma_data[-1:-n]
acf(sma_data,length(sma_data))
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 (!).
2025 Jan 02
1
Possible issue in stats/arima.R package
On 2025-01-02 11:20 a.m., Duncan Murdoch wrote:
> On 2025-01-02 9:04 a.m., Norbert Kuder wrote:
>> Hello all,
>>
>> I am running R version 4.4.2 (2024-10-31 ucrt) on Windows 10 x64, and
>> noticed something that might be a minor bug (or at least inconsistent code)
>> in the stats/arima.R package.
>> I have found:
>> 1. A missing stop() call at line 69:
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 )
{
2008 Jul 23
1
Time series reliability questions
Hello all,
I have been using R's time series capabilities to perform analysis for quite
some time now and I am having some questions regarding its reliability. In
several cases I have had substantial disagreement between R and other packages
(such as gretl and the commercial EViews package).
I have just encountered another problem and thought I'd post it to the list. In
this case,