Displaying 20 results from an estimated 800 matches similar to: "What are the differences between ACF and PACF in time seriesanalysis?"
2010 Jul 22
0
Please advise acf and pacf in order to determine order of Arima
I have data as below.Please let me know how the ACF and Pacf used to
determine the order od arima model.
Is there any rules need to be followed to determine order.Please advise
> turkey.price.ts
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
2001 1.58 1.75 1.63 1.45 1.56 2.07 1.81 1.74 1.54 1.45 0.57 1.15
2002 1.50 1.66 1.34 1.67 1.81 1.60 1.70 1.87 1.47 1.59 0.74 0.82
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
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]]
2006 Mar 23
2
Default lag.max in ACF
Hi,
The default value for lag.max in ACF implementation is 10*log10(N)
There several publications recommending setting lag.max to:
- N/4 (Box and Jenkins, 1970; Chatfield, 1975; Anderson, 1976;
Pankratz, 1983; Davis, 1986; etc.)
- sqrt(N)+10 (Cryer, 1986)
- 20<=N<=40 (Brockwell and Davis)
Why R uses 10*log10(N) as a default?
Please, give me a reference to a book or article where the
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,
2012 Nov 13
0
GAM model to reduce PACF of a model
I have asked this question on Stackoverflow and was told it does not relate
to the sites' mission as it is statistical question, thus I brought it here.
I am fitting a gam mode in the mgcv package to study associations of
environmental pollutants and mortality. The aim is to choose a model with
lowest mgcv and also to reduce the PACF to less than < |0.1|.
library(gamair)
library(mgcv)
2003 Sep 08
2
pacf lags
pacf in devel seems by default to return a different number of lags
than 1.7.1 for $pacf. I don't see any mention of this in the NEWS file,
or any change in the documentation, so I suspect it is and error,
though it may be an undocumented improvement.
(Newbie question: How is the simplest way to display a function like
pacf.default that is not exported from a namespace?)
Paul
2000 Jun 20
1
pacf
Dear list,
according to the documentation of acf{ts}
"the partial correlation coefficient is estimated by fitting
autoregressive models of successively higher orders up to lag.max. "
However, R seems to return the Yule-Walker estimates of the PACF by
default. You can check this using c(1:10) as the series: the YW
estimates are 0.7000000 and -0.1527035 for lags 1 and 2 . If the PACF
2009 Sep 11
2
How to Label Certain Lags for a PACF Graph
When I use the command for PACF, lags 5, 10, 15, and 20 are labeled. I would
like to label lag 1. I would greatly appreciate if someone could tell me how
to do this. Below is the command that I am using:
pacf(data$R1,main="Series R1 Residuals")
[[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
2007 Nov 23
1
Bug in pacf -- Proposed patch (PR#10455)
Dear all,
following the thread
http://tolstoy.newcastle.edu.au/R/e2/devel/07/09/4338.html
regarding the bug in the partial autocorrelation function for
multivariate time series.
I have prepared a web page with patches and relevant information.
http://www2.stat.unibo.it/giannerini/R/pacf.htm
Please do not hesitate to contact me for further clarifications
regards
Simone
--
2007 Nov 23
0
Bug in pacf -- Proposed patch
Dear all,
following the thread
http://tolstoy.newcastle.edu.au/R/e2/devel/07/09/4338.html
regarding the bug in the partial autocorrelation function for
multivariate time series.
I have prepared a web page with patches and relevant information.
http://www2.stat.unibo.it/giannerini/R/pacf.htm
Please do not hesitate to contact me for further clarifications
regards
Simone
--
2006 Oct 02
1
CCF and ACF
Dear all,
given two numeric vectors x and y, the ACF(x) at lag k is
cor(x(t),x(t+k)) while the CCF(x,y) at lag k is cor(x(t),y(t-k)). See
below for a simple example.
> set.seed(1)
> x <- rnorm(10)
> y <- rnorm(10)
> x
[1] -0.6264538 0.1836433 -0.8356286 1.5952808 0.3295078 -0.8204684
0.4874291 0.7383247 0.5757814 -0.3053884
> y
[1] 1.51178117 0.38984324
2011 Feb 25
0
time series with NA - acf - tsdiag - Ljung-Box
Hi all,
I am modelling a time series with missing data.
*Q1)* However, I am not sure if I should use the next *graphics* to
understand my data:
*a)* ACF & PACF (original series)
*b)* ACF & PACF (residuals)
* *
*Q2)* I am using *tsdiag*, so I obtain a graphic with 3 plots: stand.
residuals vs time; acf for residuals; Ljung-Box for residuals (it is wrong
for residuals).
I know that using
2004 Aug 10
0
Check failed after compilation (PR#7159)
Full_Name: Madeleine Yeh
Version: 1.9.1
OS: AIX 5.2
Submission from: (NULL) (151.121.225.1)
After compiling R-1.9.1 on AIX 5.2 using the IBM cc compiler, I ran the
checks. One of them failed. Here is the output from running the check solo.
root@svweb:/fsapps/test/build/R/1.9.1/R-1.9.1/tests/Examples:
># ../../bin/R --vanilla < stats-Ex.R
R : Copyright 2004, The R
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,
2009 Sep 29
0
time series and ACF
Hey guys,
im sort of a beginner with R, but here's what i need to do.
i need to perform a time series analysis on a set of financial data that i've been given. im trying to look at the ACF and PACF and fit it to a particular model (i think its the ARIMA model because i've read that financial data resembles the random walk, where the ARIMA model fits). is this correct?
if my data is
2009 Sep 30
0
FW: time series and ACF
Hey guys,
im sort of a beginner with R, but here's what i need to do.
i need to perform a time series analysis on a set of financial data that i've been given. im trying to look at the ACF and PACF and fit it to a particular model (i think its the ARIMA model because i've read that financial data resembles the random walk, where the ARIMA model fits). is this correct?
if my data is