Displaying 20 results from an estimated 300 matches similar to: "Box Ljung Statistics"
2004 Apr 17
3
Box-Ljung p-value -> Test for Independence
Hi all
I'm using the Box-Ljung test (from within R) to test if a time-series in
independently distributed.
2 questions:
1) p-value returned by Box-Ljung:
IF I want to test if the time-series is independant at say 0.05
sig-level (it means that prob of erroneously accepting that the
time-series is independent is 0.05 right?)
--> then do I consider time-series as "independant"
2011 Aug 27
1
Degrees of freedom in the Ljung-Box test
Dear list members,
I have 982 quotations of a given stock index and I want to run a Ljung-Box
test on these data to test for autocorrelation. Later on I will estimate 8
coefficients.
I do not know how many degrees of freedom should I assume in the formula for
Ljung-Box test. Could anyone tell me please?
Below the formula:
Box.test(x, lag = ????, type = c("Ljung-Box"), fitdf = 0)
2012 Jun 26
2
Ljung-Box test (Box.test)
I fit a simple linear model y = bX to a data set today, and that produced 24 residuals (I have 24 data points, one for each year from 1984-2007). I would like to test the time-independence of the residuals of my model, and I was recommended by my supervisor to use the Ljung-Box test. The Box.test function in R takes 4 arguments:
x a numeric vector or univariate time series.
lag the statistic
2006 May 17
1
can Box test the Ljung Box test say which ARIMA model is better?
two ARIMA models, both have several bars signicant in ACF and PACF plots of
their residuals,
but when run Ljung Box tests,
both don't show any significant correlations...
however, one model has p-value that is larger than the other model,
based on the p-values,
can I say the model with larger p-values should be better than the model
with smaller p-values?
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2009 Mar 31
1
Jarque-Bera test and Ljung-Box test for multivariate time series
Hi!
I know that there is function in fBasics package for univariate Jarque-Bera
test and a funtion for univariate Ljung-Box test in stats package. But I am
wondering if there is a function somewhere to do the tests for multivariate
time series?
Thanks,
John
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2006 Feb 15
1
question about the results given by the Box.test?
Hello, I am using the Ljung Box test in R to compute
if the resiudals of my fitted model is random or not.
I am not sure though what the results mean, I have
looked at various sources on the internet and have
come up with contrasting explanations (mainly because
these info deal with different program languages, like
SAS, SPSS, etc).
I know that my residuals should appropriate white
noise( is
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
2008 May 16
2
Box.test degrees of freedom
Dear colleagues,
I am new to R and statistics so please keep that in mind.
I have doubts on the df calculation of Ljung-Box test (Box.test). The
function seems to use always the df=lag=m and not df=m-p-q like suggested in
Ljung and Box (1978) paper (that is referenced).
Do you agree with this? If so, is there an R package function that computes
Ljung-Box test with the degrees of
2009 Feb 24
1
Box.test reference correction (PR#13554)
Full_Name: Peter Solymos
Version: 2.8.1
OS: Windows
Submission from: (NULL) (129.128.141.92)
The help page of the Box.test function (stats) states that the Ljung-Box test
was published in:
Ljung, G. M. and Box, G. E. P. (1978), On a measure of lack of fit in time
series models. Biometrika 65, 553--564.
The page numbers are incorrect. The correct citation should be as follows:
Ljung, G. M.
2006 Mar 08
1
Degrees of freedom using Box.test()
After an RSiteSeach("Box.test") I found some discussion regarding the degrees
of freedom in the computation of the Ljung-Box test using Box.test(), but did
not find any posting about the proper degrees of freedom.
Box.test() uses "lag=number" as the degrees of freedom. However, I believe
the correct degrees of freedom should be "number-p-q" where p and q are
2011 Oct 05
2
creating a loop for a function
Dear All,
I want to create a loop within a function r. The example follows:
Box.test (lfut, lag = 1, type="Ljung")
if i want to compute the Box.test for lag 1 to 10, I have to write manually
change each time for different lag. So i wan to write a loop for the lag 1
to 10 and return the statistics for each lag. Is there any method to do this
?
With regards,
Upananda
--
You may
2004 Jan 13
3
How can I test if a not independently and not identically distributed time series residuals' are uncorrelated ?
I'm analizing the Argentina stock market (merv)
I download the data from yahoo
library(tseries)
Argentina <- get.hist.quote(instrument="^MERV","1996-10-08","2003-11-03", quote="Close")
merv <- na.remove(log(Argentina))
I made the Augmented Dickey-Fuller test to analyse
if merv have unit root:
adf.test(merv,k=13)
Dickey-Fuller = -1.4645,
2007 Dec 08
2
time series tests
Hi all,
Can anyone clear my doubts about what conclusions to take with the following what puts of some time series tests:
> adf.test(melbmax)
Augmented Dickey-Fuller Test
data: melbmax
Dickey-Fuller = -5.4075, Lag order = 15, p-value = 0.01
alternative hypothesis: stationary
Warning message:
p-value smaller than printed p-value in: adf.test(melbmax)
2005 Jul 07
1
spurious regression in R
Hi:
I am trying to do a spurious regression in R but I
can not find the function. Anybody used it before? The
problem I have is try to do a regression with several
time series. An alternative is to use the GLS function
to fit the linear regression with the correlation
structure AR(3) for the response (or residual). I hope
the residuals after the GLS regression will be
independent judged by
2010 Jul 22
1
tsdiag
HI list,
I want to know whether tsdiag uses k-(p+q) as the lag in ljung box
test. How is it possible to save those values
nuncio
--
Nuncio.M
Research Scientist
National Center for Antarctic and Ocean research
Head land Sada
Vasco da Gamma
Goa-403804
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2004 Jan 14
3
How can I test if time series residuals' are uncorrelated ?
Ok I made Jarque-Bera test to the residuals (merv.reg$residual)
library(tseries)
jarque.bera.test(merv.reg$residual)
X-squared = 1772.369, df = 2, p-value = < 2.2e-16
And I reject the null hypotesis (H0: merv.reg$residual are normally
distributed)
So I know that:
1 - merv.reg$residual aren't independently distributed (Box-Ljung test)
2 - merv.reg$residual aren't indentically
2002 Dec 09
1
heteroscedasticity analysis
Hello,
First, sorry for my poor english, I will try to be understood.
It's the first time I try this "r-help mailing list" and I hope it will be
a success.
I am working on heteroscedasticity analysis. I would like to get the
"Box-Ljung" and the "Lagrange multipliers" test.
I found the first one in the library "ts", but I can't find the second one.
2012 Jun 06
3
Predict in the package R2BayesX
Hi all
I'm using the function bayesx to estimate a simple model, for example:
library(R2BayesX)
## generate some data
set.seed(111)
n <- 200
## regressor
dat <- data.frame(x = runif(n, -3, 3))
## response
dat$y <- with(dat, 1.5 + sin(x) + rnorm(n, sd = 0.6))
## estimate models with
## bayesx REML and MCMC
b1 <- bayesx(y ~ sx(x), method = "REML", data = dat)
I want
2011 Sep 27
4
Question concerning Box.test
Hi everyone,
I've got a question concerning the function Box.test for testing
autocorrelation in my data.
My data consist of (daily) returns of several stocks over time (first
row=time, all other rows=stock returns). I intend to perform a Box-Ljung
test for my returns (for each stock). Since I have about 3000 stocks in my
list, I'm not able to perform the test individually for each
2005 Oct 31
2
How can I test temporal autocorrelation of binary data?
Hi,
I have a binary (o/1 - coded) data set and want to test it's autocorrelation
structure. Is that function implemented in R?
Can I use the ACF - funtion with binary data?
Thanks for your help,
Daniel