Displaying 20 results from an estimated 2000 matches similar to: "tests for non-stationarity"
2008 Jan 21
4
Stationarity of a Time Series
Does anyone know of a test for stationarity of a time series, or like
all ordination techniques it is a qualitative assessment of a
quantitative result. Books, papers, etc. suggestions welcome.
thanks
Stephen
--
Let's not spend our time and resources thinking about things that are
so little or so large that all they really do for us is puff us up and
make us feel like gods. We are
2009 Oct 30
1
how to test for stationarity in time series?
Hi all,
Could anybody tell me how to test for stationarity in time series?
Thanks a lot!
[[alternative HTML version deleted]]
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
2006 Jul 06
2
KPSS test
Hi,
Am I interpreting the results properly? Are my conclusions correct?
> KPSS.test(df)
---- ----
KPSS test
---- ----
Null hypotheses: Level stationarity and stationarity around a linear trend.
Alternative hypothesis: Unit root.
----
Statistic for the null hypothesis of
level stationarity: 1.089
Critical values:
0.10 0.05 0.025 0.01
0.347 0.463
2006 Jul 06
1
Access values in kpssstat-class
Hi,
How can I access the Values stored in kpssstat-class given by KPSS.test function and store it in a variable.
For example:
>x <- rnorm(1000)
>test <- KPSS.test(ts(x))
>test
---- ----
KPSS test
---- ----
Null hypotheses: Level stationarity and stationarity around a linear trend.
Alternative hypothesis: Unit root.
----
Statistic for the null
2007 Oct 26
2
calculating correlation of a Supply/Demand measure and price change (in high frequency time series data)
Regarding "financial" data: I have a high frequency (1 minute) measure of
supply/demand and I'd like to know if it has any influence on short term
price changes (also 1 minute).
Question: How do I calculate the correlation between this supply/demand
measure and price changes (correctly)?
Some facts about that data:
The price changes and supply/demand measure are non-normal. An
2007 Nov 26
3
Time Series Issues, Stationarity ..
Hello,
I am very new to R and Time Series. I need some help including R codes
about the following issues. I' ll really appreciate any number of
answers...
# I have a time series data composed of 24 values:
myinput = c(n1,n2...,n24);
# In order to make a forecasting a, I use the following codes
result1 = arima(ts(myinput),order = c(p,d,q),seasonal = list(order=c(P,D,Q)))
result2 =
2003 Apr 17
2
Testing for Stationarity of time series
Hi there,
Does anyone know if R has a function for testing whether a time series is
stationary??
Thanks in advance,
Wayne
Dr Wayne R. Jones
Statistician / Research Analyst
KSS Group plc
St James's Buildings
79 Oxford Street
Manchester M1 6SS
Tel: +44(0)161 609 4084
Mob: +44(0)7810 523 713
KSS Ltd
A division of Knowledge Support Systems Group plc
Seventh Floor St James's
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 Mar 09
1
about kpss.test()
Hi All,
First of all, could you tell me what the "KPSS Level"
in the output of the test means?
I have a series, x, of periodic data and tried
kpss.test() on it to verify its stationarity. The
tests
gave me the p-value above 0.1. Since the null
hypothesis N0 is that the series _is_ stationary, this
means that I cannot reject N0. But the series does
look
periodic!
So does all this
2005 Mar 08
2
The null hypothesis in kpss test (kpss.test())
is that 'x' is level or trend stationary. I did this
> s<-rnorm(1000)
> kpss.test(s)
KPSS Test for Level Stationarity
data: s
KPSS Level = 0.0429, Truncation lag parameter = 7,
p-value = 0.1
Warning message:
p-value greater than printed p-value in:
kpss.test(s)
My question is whether p=0.1 is a good number to
reject
N0? On the other hand, I have a
2005 May 02
1
Trying to understand kpss.test() in tseries package
I'm trying to understand how to use kpss.test() properly. If I have a
level stationary series like rnorm() in the help page, shouldn't I get a
small p-value with the null hypothesis set to "Trend"? The (condensed)
output from kpss.test() for the two possible null hypotheses is given
below. I don't see any significant difference between these results.
> x <-
2023 Apr 01
1
weird things in seqMK() and sqmk()
Hello The other say I posted a question about altering confidence limits
in the seqMK() function in the pheno package. I didn't get any bites but
in any case I've been trying to use this function. It seems to me to give
very odd results - sometimes identifying 8 or 9 changepoints in a
relatively short vector of maybe 40 elements, and at other times not giving
any changepoints at all,
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"
2011 Jan 04
2
unicode variable and function names?
Dear List,
Is it possible to have function names like ? (unicode universal quantifier)?
This question is inspired by agda source code, which supports this.
http://www.cs.nott.ac.uk/~nad/listings/lib-0.4/Algebra.html
It would be handy to use. My guess is, however, that it's not supportet in R.
Regards,
Steve
2005 Jan 25
1
CODA vs. BOA discrepancy
Dear List:
the CODA and BOA packages for the analysis of MCMC output yield different
results on two dignostic test of convergence: 1) Geweke's convergence
diagnostic; 2) Heidelberger and Welch's convergence diagnostic. Does that
imply that the CODA and BOA packages implement different ``flavors'' of
the same test?
I paste below an example.
Geweke's test
2008 Jan 10
1
question regarding kpss tests from urca, uroot and tseries packages
Hi R users!
I've come across using kpss tests for time series analysis and i have a question that troubles me since i don't have much experience with time series and the mathematical part underlining it.
x<-c(253, 252, 275, 275, 272, 254, 272, 252, 249, 300, 244,
258, 255, 285, 301, 278, 279, 304, 275, 276, 313, 292, 302,
322, 281, 298, 305, 295, 286, 327, 286, 270, 289, 293, 287,
2011 Dec 09
2
[LLVMdev] Adding option to LLVM opt to disable a specific pass from command line
David,
I think my explanation is not clear, my front-end did NOTt generate
'llvm.memcpy' it generate LL code that after use of LLVM 'opt' get
transformed by 'loop-idom' pass into an 'llvm.memcpy' for an overlapping
loop:
static void
t0(int n)
{
int i;
for (i=0; i<n; i++)
result[i+1] = result[i];
}
Then 'llc' expanded llvm.memcpy into a
2009 Mar 20
2
[LLVMdev] Possible memory leakage in the LLVM JIT Engine
Hi,
In my application I am JITing thousands of functions, though I am doing it
sequantially and running only one at a time. So it is crucial to be able to
properly clean up the memory from an old JITed function when JITing and
running the new one.
I am using Haskell binding of LLVM and my application works OK. However,
memory usage increases and never decreases during the run time of my
2011 Dec 09
0
[LLVMdev] Adding option to LLVM opt to disable a specific pass from command line
On Fri, Dec 09, 2011 at 10:03:37AM +0100, Seb wrote:
> I think my explanation is not clear, my front-end did NOTt generate
> 'llvm.memcpy' it generate LL code that after use of LLVM 'opt' get
> transformed by 'loop-idom' pass into an 'llvm.memcpy' for an overlapping
> loop:
>
> static void
> t0(int n)
> {
> int i;
> for (i=0;