similar to: SARIMA

Displaying 20 results from an estimated 2000 matches similar to: "SARIMA"

2009 May 20
1
stationarity tests
How can I make sure the residual signal, after subtracting the trend extracted through some technique, is actually trend-free ? I would greatly appreciate any suggestion about some Stationarity tests. I'd like to make sure I have got the difference between ACF and PACF right. In the following I am citing some definitions. I would appreciate your thoughts. ACF(k) estimates the correlation
2008 Aug 28
3
Plots spanning columns
Hi! I want to plot three graphs (residuals, ACF and PACF of a model). Ideally I would use a c(2,2) disposition where the residuals plot would start at position 1,1 and span to position 1,2. Then I would plot the ACF in position 2,1 and the PACF in position 2,2. Maybe is clearer like this: -------------------------- | | | residuals | |
2004 Aug 17
1
suggestion for ARMAacf()
hi, in 1.9.1, the return value from ARMAacf(pacf=TRUE) is not named by lags, contrary to ?ARMAacf. the simple fix is to move names(Acf) <- down after if(pacf), with an appropriate starting lag as pacf=TRUE appears to start at lag 1 (whereas pacf=FALSE starts at lag 0). for consistency, one could argue to append 1 for lag 0 for pacf=TRUE (or start pacf=F at lag 1). however, given the
2004 Aug 09
1
Easy acf and pacf for irregular time series in R
R: Is there an easy way to get the acf and pacf for an irregular times series? That is, the acf and pacf with lag lengths that are in units of time, not observation number. Thanks, Jason Higbee Research Associate Federal Reserve Bank of St. Louis The views expressed in this email are the author's and not necessarily those of the Federal Reserve Bank of St. Louis or the Federal Reserve
2000 Jun 20
1
pacf
Dear list, according to the documentation of acf{ts} "the partial correlation coefficient is estimated by fitting autoregressive models of successively higher orders up to lag.max. " However, R seems to return the Yule-Walker estimates of the PACF by default. You can check this using c(1:10) as the series: the YW estimates are 0.7000000 and -0.1527035 for lags 1 and 2 . If the PACF
2012 Dec 30
1
acf () and pacf()
I have used acf() and pacf() in R to get the acf and pacf values at max/lag=20 but the output did not show the values associated with lag numbers. lag numbers is shown in decimals. -- Rashid Ameer View my recent publication at * http://www.emeraldinsight.com/fwd.htm?id=aob&ini=aob&doi=10.1108/17538391211282854 * Details for my works are available directly at
2018 Aug 30
2
Cambiar la escala del eje x
Estimados amigos Estoy dibujando las funciones acf y pacf de una variable de una serie "zoo": > ls.str(pat="T0.5") T0.5 : 'zoo' series from 2017-11-08 23:00:00 to 2017-11-15 06:59:00   Data: num [1:9120, 1:3] 55 49.8 51 50.1 36.5 ...   Index:  POSIXct[1:9120], format: "2017-11-08 23:00:00" "2017-11-08 23:01:00" "2017-11-08
2010 Feb 11
1
ACF and PACF
Hi helpers, can you help me in plotting acf and pacf functions in R. I am using the code acf(variable name) but it is not working. Expecting your reply. Thanks -- View this message in context: http://n4.nabble.com/ACF-and-PACF-tp1477149p1477149.html Sent from the R help mailing list archive at Nabble.com.
2007 Apr 27
1
acf and pacf plot
Hi, I noticed that whenever I ran acf or pacf, the plot generated by R always includes two horizontal blue doted lines. Furthermore, these two lines are not documented in the acf documentation. I don't know what they are for, but it seems that they are important. Could someone tell me what they are and how are they calculated? Thanks, -- Tom [[alternative HTML version deleted]]
2007 Apr 28
1
pacf
Hi, I wanted to understand exactly how acf and pacf works, so I tried to calculate ac and pac manually. For ac, I used the standard acf formula: acf(k) = sum(X(t)-Xbar)(X(t-k)-Xbar))/sum(X(t)-Xbar)^2. But for pac, I could not figure out how to calculate it by hand. I understand that in both R and EVIEWS, it is done using the Durbin-Levinson algorithm by the computer. However, I don't
2010 Oct 29
1
SARIMA simulation using time series history
Hi, I'm currently working with a SARIMA model from which I want to make simulations. As I understand, neither sarima.Sim nor the functions in the gsarima package use historic realizations of the time series to simulate future values. However, I want to use historic values as input and simulate future values based on the history. Anyone who know whether such a function is available
2007 Nov 21
1
problem modeling time series
Good afternoon! I'm trying to model a ts but unfortunately i'.m very new to this kind of modeling so i 'll be very grateful if you have an advice. This was my syntax:
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
2004 Mar 09
2
corARMA and ACF in nlme
Hi R-sters, Just wondering what I might be doing wrong. I'm trying to fit a multiple linear regression model, and being ever mindful about the possibilities of autocorrelation in the errors (it's a time series), the errors appear to follow an AR1 process (ar(ts(glsfit$residuals)) selected order 1). So, when I go back and try to do the simultaneous regression and error fit with gls,
2006 Mar 04
1
replicated time series - lme?
Dear R-helpers, I have a time series analysis problem in R: I want to analyse the output of my simulation model which is proportional cover of shrubs in a savanna plot for each of 500 successive years. I have run the model (which includes stochasticity, especially in the initial conditions) 17 times generating 17 time series of shrub cover. I am interested in a possible periodicity of shrub
2003 Apr 02
2
pacf.mts
I am getting the following: *** Weave Errors *** Error in driver$runcode(drobj, chunk, chunkopts) : Error in eval(expr, envir, enclos) : couldn't find function "pacf.mts" *** Source Errors *** Error in eval(expr, envir, enclos) : couldn't find function "pacf.mts" make[1]: *** [checkVignettes] Error 1 I don't really understand the new namespace mechanism,
2011 Jan 19
2
CCF and missing values.
Hi, I have missing values in my time series. "na.action = na.pass" works for acf and pacf. Why do I get the following error for the ccf? > ts(matrix(c(dev$u[1:10],dev$q[1:10]),ncol=2),start=1,freq=1) Time Series: Start = 1 End = 10 Frequency = 1 Series 1 Series 2 1 68.00000 138.4615 2 70.00000 355.5556 3 68.76000 304.3200 4 68.00000 231.4286 5 69.74194 357.4963 6
2006 Aug 30
1
How to put title Vertically
Dear all R users, Suppose, Dear all R users, Suppose, pauto.cor = pacf(lh, plot=F) max.lag = max(pauto.cor$lag) min.lag = min(pauto.cor$lag) centre = (max.lag - min.lag)/2 pauto.cor = pauto.cor$acf pauto.cor = pauto.cor[-1] par(mar=c(3,0,1,1)) barplot(pauto.cor, axes=F,xlim=c(max(pauto.cor), min(pauto.cor)), space=0, col="green4",border="green",horiz=T) #This plots
2004 Mar 03
1
partial autocorrelation for Rt vs. Nt-1, ......., Nt-h
Dear list, following a previous querry we are still stuck! As pointed out by Erin Hodges the "ts" library includes a PACF function which reports the partial correlation of population density at time t against lagged population density. However, what we are trying to calculate is the partial correlation between rate of population change, Rt=log Nt/Nt-1, against lagged population
2009 Feb 07
3
Output results to a single postscript document
Hello R users, I have been trying to output all my results (text, plots, etc) into the same postscript file as one document, but have been unable to...Can anyone help me improve my code below so that I can accomplish this? Currently I have to output them separately then piece them back together into one document.. Thanks in Advance for any help! options (scipen=999, digits=7)