similar to: ARMAX Models in R

Displaying 20 results from an estimated 700 matches similar to: "ARMAX Models in R"

2010 May 21
1
i have question about ARMAX
Pro, I am PhD student , i am usuing Rational Expectations Model, I want to model different timeseries with ARMAX models in R because I think that ARMAX models will map best to these data. I want know the steps to use R for ARMAX models I coudn't find any solutions in the R help and therefore I want to ask all of you. Does anyone know how to solve this problem??? That would be
2003 Nov 24
0
link between arima and arma fit
Hi dear sirs, I am wondering why the fit of the time serie x with an arima and the fit of diff(x) with an arma (same coeff p & d) differ one from another here are the output of R: %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% > modelarma<-arma(diff(x),c(7,5)) > modelarma Call: arma(x = diff(x), order = c(7, 5)) Coefficient(s): ar1 ar2 ar3 ar4 ar5 ar6 ar7 ma1 ma2 0.06078
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
2008 Nov 20
2
Reformatting a table
Hi !            I am new to R. Can somebody help me in reformatting huge output files ,i.e, rearranging sets of columns in specific order. For example: I have data for three compunds 1, 2 and 3 file1: ID CA1 CA3 CA2 MA2 MA1 MA3 1 14 15 13 7 12 3 2 19 7 12 10 14 5 3 21 12 19 6 8 9   to File 2:   ID CA1 CA2 CA3 MA1 MA2 MA3 1 14 13 15 12 7 3 2 19 12 7 14 10 5 3 21 19 12 8 6 9   or File3: ID
2006 Dec 08
5
Remove " from a string
Hi all! I have lots of functions called in the following pattern 'NameOfFunctionNumber' where the name always stays the same and the number varies from 1 to 98. Another function which I run in advance returns the number of the function which has to be called next. Now I want to combine 'NameOfFunction' with the 'Number' returned so that i can call the desired function. I
2009 Mar 26
1
arima, xreg, and the armax model
Hello all, I''m having fun again with the arima function. This time I read in: http://www.stat.pitt.edu/stoffer/tsa2/R_time_series_quick_fix.htm <<It has recently been suggested (by a reliable source) that using xreg in arima() does NOT fit an ARMAX model [insert slap head icon here]. This will be investigated as soon as time permits.>> (by R.H. Shumway & D.S. Stoffer)
2011 Feb 16
0
Arima contents
Hello, I'm running a number of arima models using the "arima" function. Often, when lag length gets too high, these model don't converge and an error message appears as this: > reg <- arima(y,order=c(7,0,7),xreg=isr) Warning message: In arima(y, order = c(7, 0, 7), xreg = isr) : possible convergence problem: optim gave code=1 In this case, when you print the results
2009 Nov 16
1
ARMAX model fitting with arima
I am trying to understand how to fit an ARMAX model with the arima function from the stats package. I tried the simple data below, where the time series (vector x) is generated by filtering a step function (vector u, the exogenous signal) through a lowpass filter with AR coefficient equal to 0.8. The input gain is 0.3 and there is a 0.01 normal white noise added to the output: x <- u
2009 Feb 20
0
residuals from a fractional arima model and other questions
Dear list and Martin, I'm testing different approaches to fit an electricity demand time series and come upon the fracdiff package (v 1.3-1) for fitting fractional ARIMA models. The following questions are motivated by this package. 1. Despite having a help page, the residuals and fitted functions don't seem to have implementation, or did i miss something obvious? Alternatively, having a
2011 Nov 14
1
string to list()
I can get an array of strings for the data that I want using 'paste()' as follows: paste('ma', 1:am$arma[2], '=', coef(am)[1:am$arma[2] + am$arma[1]], sep='') This results in a vector of strings like: [1] "ma1=1.17760133668255" "ma2=0.649795570407939" "ma3=0.329456750858276" What I would like is fixed.pars <-
2009 Jan 23
1
forecasting error?
Hello everybody! I have an ARIMA model for a time series. This model was obtained through an auto.arima function. The resulting model is a ARIMA(2,1,4)(2,0,1)[12] with drift (my time series has monthly data). Then I perform a 12-step ahead forecast to the cited model... so far so good... but when I look the plot of my forecast I see that the result is really far from the behavior of my time
2003 Apr 30
2
Bug in arima?
I'm using the fixed argument in arima. Shouldn't ar4, ar5, and ar6 display as zero in the output? Call: arima(x = window(log(hhprice), start = c(1990, 1), end = c(2003, 3)), order = c(7, 1, 0), xreg = window(ts.union(exa1 = lag(exa, -1), exa12 = lag(exa, -12), exb1 = lag(exb, -1), exc1 = lag(exc, -1), exc12 = lag(exc, -12)), start = c(1990, 1), end = c(2003, 3)),
2011 Sep 12
1
Difference in function arima estimation between 2.11.1 and R 2.12.2
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
2003 Dec 18
1
Help with predict.Arima with external regressor values [Repalced]
Hi all there I am enjoying R since 2 weeks and I come to my first deadlock, il am trying to use predict.Arima in the ts package. I get a "Error in cbind(...) : cannot create a matrix from these types" -- Start R session ----------------------------------------------------- > fitdiv <- arima(data, c(2, 0, 3), xreg = y ) ; print(fitdiv) Call: arima(x = data, order = c(2, 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,
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? >
2003 Dec 18
0
Help with predict.Arima with external regressor values
Hi all there I am enjoying R since 2 weeks and I come to my first deadlock, il am trying to use predict.Arima in the ts package. I get a "Error in cbind(...) : cannot create a matrix from these types" -- Start R session ----------------------------------------------------- > fitdiv <- arima(data, c(2, 0, 3), xreg = y ) ; print(fitdiv) Call: arima(x = data, order = c(2, 0, 3),
2008 Sep 10
2
arima and xreg
Dear R-help-archive.. I am trying to figure out how to make arima prediction when I have a process involving multivariate time series input, and one output time series (output is to be predicted) .. (thus strictly speaking its an ARMAX process). I know that the arima function of R was not designed to handle multivariate analysis (there is dse but it doesnt handle arma multivariate analysis, only
2004 Jun 22
3
[LLVMdev] Linearscan allocator bug?
Folks, I'm running into something which looks like a bug in linearscan allocator. Of course I can't be 100% sure it's not some unobvious mistake on my part, so I'd like to hear your opinion. First, I attach two files -- LLVM asm and the asm for my target. The problem with assembler is: on line 171 it uses register gr2, which is copied from gr6 above, on line 161. The only
2010 Dec 06
10
R crashes when making graphs
hi, i am running R with JGR and Deducer under Ubuntu Mint Lucid. since i updated to R 2.12 i can no longer make graphs - R just crashes. the full error report was posted to launchpad (https://bugs.launchpad.net/ubuntu/+source/openjdk-6/+bug/675905) without any success so far. anyone with a similar problem or helpful suggestions? thanks! kat