Displaying 20 results from an estimated 7000 matches similar to: "getting p-values from fitted ARIMA"
2013 Mar 30
1
vcovHC and arima() output
Dear all,
how can I use vcovHC() to get robust/corrected standard errors from an
arima() output?
I ran an arima model with AR(1) and got the estimate, se, zvalue and
p-value using coeftest(arima.output).
However, I cannot use vcovHC(arima.output) to get corrected standard
errors. It seems vcovHC works only with lm and plm objects?
Is there another way I can get robust/corrected
2011 Feb 25
1
Question about foreach (with doSNOW), is that a bug?
Hi all,
Within a foreach loop with doSNOW, we cant call functions which come from
the non-default package. We need to load(require/library) the package once
more within the foreach loop. Anyone knows why would happen like this? Is it
caused by the snow package and something happened when "snow" parallelize
the job?
Other than load the package once more with in the foreach loop, is
2010 Jun 08
2
how to ignore rows missing arguments of a function when creating a function?
Hi,
I am relatively new to R; when creating functions, I run into problems with
missing values. I would like my functions to ignore rows with missing values
for arguments of my function) in the analysis (as for example is the case in
STATA). Note that I don't want my function to drop rows if there are missing
arguments elsewhere in a row, ie for variables that are not arguments of my
2013 Jan 20
3
strucchange breakpoints r-squared
Can anyone please tell me how to get the r-squared output from a piecewise
(segmented) regression using the strucchange package? Here is the R code I
have tried thus far.
library(lmtest)
library(strucchange)
data <- ts(c(rnorm(30), runif(30)), frequency = 12, start = c(2005, 01))
bpts <- breakpoints(data ~ 1)
print(bpts)
summary(bpts)
coeftest(bpts)
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2006 Jan 02
1
Use Of makeARIMA
Hi R-Experts,
Currently I'm using an univariate time series in which I'm going to
apply KalmanLike(),KalmanForecast (),KalmanSmooth(), KalmanRun(). For I
use it before makeARIMA () but I don't understand and i don't know to
include the seasonal coefficients. Can anyone help me citing a suitable
example? Thanks in advance.
------------------------------------------
2009 Jun 22
2
p-values for ARIMA coefficients
Hi,
I'm a beginner using R and I'm modeling a time series with ARIMA.
I'm looking for a way to determine the p-values of the coefficients of my model.
Does ARIMA function return these values? or is there a way to determine them easily?
Thanks for your answer
Myriam
2012 Mar 19
1
what is p,d & q in arima() function of time series
i am new to time series
i found in help about arima
arima(x = data, order = c(p, d, q))
what is exactly p,d,q? if i not changed them,what effects will happens?
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2011 Jul 25
1
predict() and heteroskedasticity-robust standard errors
Hello there,
I have a linear regression model for which I estimated
heteroskedasticity-robust (Huber-White) standard errors using the
coeftest function
in the lmtest-package.
Now I would like to inspect the predicted values of the dependent
variable for particular groups and include a confidence interval for
this prediction.
My question: is it possible to estimate confidence intervals for the
2005 Aug 29
1
Different sings for correlations in OLS and TSA
Dear list,
I am trying to re-analyse something. I do have two time series, one
of which (ts.mar) might help explaining the other (ts.anr). In the
original analysis, no-one seems to have cared about the data being
time-series and they just did OLS. This yielded a strong positive
correlation.
I want to know if this correlation is still as strong when the
autocorrelations are taken into account.
2004 Jul 21
2
Testing autocorrelation & heteroskedasticity of residuals in ts
Hi,
I'm dealing with time series. I usually use stl() to
estimate trend, stagionality and residuals. I test for
normality of residuals using shapiro.test(), but I
can't test for autocorrelation and heteroskedasticity.
Is there a way to perform Durbin-Watson test and
Breusch-Pagan test (or other simalar tests) for time
series?
I find dwtest() and bptest() in the package lmtest,
but it
2011 Jun 08
1
Autocorrelation in R
Hi,
I am trying to learn time series, and I am attending a colleague's
course on Econometrics. However, he uses e-views, and I use R. I am
trying to reproduce his examples in R, but I am having problems
specifying a AR(1) model. Would anyone help me with my code?
Thanks in advance!
Reproducible code follows:
download.file("https://sites.google.com/a/proxima.adm.br/main/ex_32.csv
2009 Mar 10
1
HAC corrected standard errors
Hi,
I have a simple linear regression for which I want to obtain HAC corrected
standard errors, since I have significant serial/auto correlation in my
residuals, and also potential heteroskedasticity.
Would anyone be able to direct me to the function that implements this in R?
It's a basic question and I'm sure I'm missing something obvious here. I
looked up this post:
2012 Apr 26
1
Using the R predict function to forecast a model fit with auto.arima function
Hello R users,
Hope everyone is doing great.
I have a dataset that is in .csv format and consists of two columns: one
named Period (which contains dates in the format yyyy_mm) and goes from
1995_10 to 2007_09 and the second column named pcumsdry which is a
volumetric measure and has been formatted as numeric without any commas or
decimals.
I imported the dataset as pauldataset and made use of
2013 Sep 09
1
Fitting Arima Models and Forecasting Using Daily Historical Data
Hello everyone,
I was trying to fit an arima model to a daily historical data, but, for
some reason, havent been able to.
I basically have 212 observations (from 12/1/2012 to 06/30/2013) containing
the number of transits for a particular vessel.
The following messages are produced by R:
dailytrans.fit<-arima(dailytrans$transits, order=c(0,1,2),
seasonal=list(order=c(0,1,2), period=365),
2007 Oct 17
1
Time Series - Function to fit ARIMA and GARCH components
I'm searching for a function to fit a conditional mean structure (ARIMA) and
a conditional variance structure (GARCH) to a data set for one model.
Particularly, I'm trying to fit an IMA(1,1)+GARCH(1,1) model to a data set.
However, I can't seem to find a function that will let me specify both the
ARIMA and GARCH components.
Any help would be appreciated!
--
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2009 Nov 16
1
ARMAX model fitting with arima
I am trying to understand how to fit an ARMAX model with the arima
function from the stats package. I tried the simple data below, where
the time series (vector x) is generated by filtering a step function
(vector u, the exogenous signal) through a lowpass filter with AR
coefficient equal to 0.8. The input gain is 0.3 and there is a 0.01
normal white noise added to the output:
x <- u
2015 Jun 26
1
[R-pkg-devel] Guidelines for S3 regression models
Stephen,
thanks for your effort. The more appropriate list for this discussion is
probably R-devel (as far as I understand it) so I've moved the discussion
there.
Related topics have already been discussed in the past. Specifically, I
remember contributions by Paul Johnson ("rockchalk" package) and John Fox
("effects" and "car" package) as their packages
2013 Apr 05
1
white heteroskedasticity standard errors NLS
Hello
Is there any function to calculate White's standard errors in R in an NLS
regression.
The sandwich and car package do it but they need an lm object to calculate
the error's.
Does anyone have idea how to do it for an NLS object ?
Regards
The woods are lovely, dark and deep
But I have promises to keep
And miles before I go to sleep
And miles before I go to sleep
-----
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2003 Jan 09
2
using arima() function
HI, there,
When i use R, i tried to use function arima(), it complains:
Error: couldn't find function "arima"
But when I type "help.search("arima") ",
I got arima() poped up..
arima(ts) ARIMA Modelling of Time Series
arima.sim(ts) Simulate from an ARIMA Model
arima0(ts) ARIMA Modelling of Time Series -- Preliminary
2007 Nov 09
1
White's test again
Hi all,
It seems that I can get White's (HC3) test using MASS. The syntax I
used for the particular problem is
anova(scireg3, white.adjust="hc3")
where scireg3 is an object from the lm function. But, the anova summary
table is all I get. I don't get the new estimates or standard errors
correcting for heteroskedasticity. Is there a way to get that information?
Thanks