Displaying 20 results from an estimated 3000 matches similar to: "stationarity tests"
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
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 |
|
2011 Nov 06
1
VAR and VECM in multivariate time series
Hello to everyone!
I am working on my final year project about multivariate time series. There
are three variables in the multivariate time series model.
I have a few questions:
1. I used acf and pacf plot and find my variables are nonstationary. But in
adf.test() and pp.test(), the data are stationary. why?
2.I use VAR to get a model. y is the matrix of data set and I have made a
once
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
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
2008 Jun 26
1
stationary "terminology" time series question
This is not exactly an R question but the R code below may make my
question more understandable.
If one plots sin(x) where x runs from -pi to pi , then the curve hovers
around zero obviously. so , in a"stationary in the mean" sense,
the series is stationary. But, clearly if one plots the acf, the
autocorrelations at lower lags are quite high and, in the "box jenkins"
2003 Apr 12
1
SARIMA
I'm trying to fit a SARIMA(p,d,q)x(P,D,Q) with seasonal period s to some data. When dealing with these types of models one often looks at the ACF and PACF of the time series at lags that are multiples of s, to identify potential values of P, Q. How would I do this in R given the original time series? Secondly given a time series x acf(x) just gives me the plot of the acf. How would I actually
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)
2009 Jan 19
1
time series contains internal NAs error
Hello R List,
I seem to have a peculiar problem. When using time series data, I get
the following error when running the acf and pacf function.
Using the function acf(dtxts,plot= TRUE,xaxt = "n",col="red",na.action
= na.omit) (where dtxts is a time series object created with package
"xts" ) results in the error below.
Error in na.omit.ts(as.ts(x)) : time series