Displaying 20 results from an estimated 3000 matches similar to: "Removing autocorrelations"
2002 Jan 09
4
Cochrane-Orcutt method
Hello,
Is there a package that implements the Cochrane-Orcutt itterative
procedure for dealing with autocorrelation in a regression model?
Thanks,
John.
--
==========================================
John Janmaat
Department of Economics
Acadia University, Wolfville, NS, B0P 1X0
(902)585-1461
All opinions stated are personal, unless
otherwise indicated.
2003 Nov 19
2
Correction for first order autocorrelation in OLS residuals
Hi there fellow R-users,
Can anyone tell me if there exits an R package that deals with serial
correlation in the residuals of an lm model.
Perhaps, using the Cochrane Orcutt or Praise Wilson methods?
Thanks,
Wayne
Dr Wayne R. Jones
Senior Statistician / Research Analyst
KSS Limited
St James's Buildings
79 Oxford Street
Manchester M1 6SS
Tel: +44(0)161 609 4084
Mob: +44(0)7810 523 713
2008 Nov 15
1
GAMs and GAMMS with correlated acoustic data
Greetings
This is a long email.
I'm struggling with a data set comprising 2,278 hydroacoustic estimates of
fish biomass density made along line transects in two lakes (lakes
Michigan and Huron, three years in each lake). The data represent
lakewide surveys in each year and each data point represents the estimate
for a horizontal interval 1 km in length.
I'm interested in comparing
2006 Aug 31
0
Moving Window regressions with corrections for Heteroscedasticity and Autocorrelations(HAC)
# Using Moving/Rolling Windows, here we do an OLS Regression with corrections for #Heteroscedasticity and Autocorrelations (HAC) using Newey West Method. This code is a #extension of Ajay Shah?s code for moving windows simple OLS regression.
# The easiest way to adjust for Autocorrelations and Heteroscedasticity in the OLS residuals is to #use the coeftest function that is included in the
2012 Sep 27
1
Package ‘orcutt’ bug?
Hello~
Did any one have used the package 'orcutt' ?
I find that it can not work smoothly in a single variable regression. I use the example following, it function very well.
But when I regress "cons" on "price" (use the "reg1<-lm(cons~price+income+temp)") , then use "reg11<-cochrane.orcutt(reg1)
". There is an error message “Error in
2011 Aug 25
1
Autocorrelation using acf
Dear R list
As suggested by Prof Brian Ripley, I have tried to read acf literature. The main problem is I am not the statistician and hence have some problem in understanding the concepts immediately. I came across one literature (http://www.stat.nus.edu.sg/~staxyc/REG32.pdf) on auto-correlation giving the methodology. As per that literature, the auto-correlation is arrived at as per following.
2004 Apr 05
1
Cochrane-Orcutt
hi everybody
i'm looking for a function to estimate a regression model via the Cochrane
Orcutt method
thanks
2011 Aug 24
1
Autocorrelation using library(tseries)
Dear R list
I am trying to understand the auto-correlation concept. Auto-correlation is the self-correlation of random variable X with a certain time lag of say t.
The article "http://www.mit.tut.fi/MIT-3010/luentokalvot/lk10-11/MDA_lecture16_11.pdf" (Page no. 9 and 10) gives the methodology as under.
Suppose you have a time series observations as say
X =
2006 Nov 27
2
NaN with ccf() for vector with all same element
hello,
i have been using ccf() to look at the correlation between lightning and electrogamnetic data. for the most part it has worked exactly as expected. however, i have come across something that puzzles me a bit:
> x <- c(1, 0, 1, 0, 1, 0)
> y <- c(0, 0, 0, 0, 0, 0)
> ccf(x, x, plot = FALSE)
Autocorrelations of series 'X', by lag
-4 -3 -2 -1 0
2009 Jan 21
1
Vector Autocorrelation Function in R?
Hello.
Does anyone know, if there is a function in R to compute the vector autocorrelations?
Thank you in advance.
Regards,
Andreas.
2012 Sep 27
2
Generating an autocorrelated binary variable
Hi R-fellows,
I am trying to simulate a multivariate correlated sample via the Gaussian copula method. One variable is a binary variable, that should be autocorrelated. The autocorrelation should be rho = 0.2. Furthermore, the overall probability to get either outcome of the binary variable should be 0.5.
Below you can see the R code (I use for simplicity a diagonal matrix in rmvnorm even if it
2008 Jun 17
1
Problems with Cochrane-Orcutt procedures
Hi John,
Hi Folks/Prof. Fox,
I found some code John Fox had written sometime back on the
Cochrane-Orcutt and Prais procedures here:
https://stat.ethz.ch/pipermail/r-help/2002-January/017774.html
I thought I would try it out and get the following errors below. Was
wondering if anyone had any immediate opinions why this might be ?
The linear model is the object regrCMSlm .
Thanks,
Tolga
2007 Oct 22
3
Spatial autocorrelation
Hi,
I have collected data on trees from 5 forest plots located within the
same landscape. Data within the plots are spatially autocorrelated
(calculated using Moran's I). I would like to do a ANCOVA type of
analysis combining these five plots, but the assumption that there is no
autocorrelation in the residuals is obviously violated. Does anyone have
any ideas how to incorporate these spatial
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.
2006 Jan 30
4
Logistic regression model selection with overdispersed/autocorrelated data
I am creating habitat selection models for caribou and other species with
data collected from GPS collars. In my current situation the radio-collars
recorded the locations of 30 caribou every 6 hours. I am then comparing
resources used at caribou locations to random locations using logistic
regression (standard habitat analysis).
The data is therefore highly autocorrelated and this causes Type
2013 Jan 09
1
How to estate the correlation between two autocorrelated variables
Dear R users,
In my data, there are two variables t1 and t2. For each observation of t1
and t2, two location indicators (x, y) were provided.
The data format is
# x y t1 t2
Since the both t1 and t2 are depended on x and y, t1 and t2 are
autocorrelated variables. My question is how to calculate the correlation
between t1 and t2 by taking into account the structure of residual variance
2007 Feb 26
1
Partial whitening of time series?
I have a time series with a one year lag, ar=0.5. The series has some
interesting events that disappear when the series is whitened (i.e.,
fitting an AR process and looking at the residuals). I'd like to remove
the autocorrelation in stages to see the effect on the time series. Is
there a way to specify the autocorrelation term while fitting an AR
process?
For instance, given the following:
2010 Aug 02
1
removing spatial auto correlation
Hi list,
I am trying to fit arima model for a grid of 360x161x338 points,
where 360x161 is the spatial dimension and 338 is the number of time steps I
have, which is seasonal. For this purpose I used the auto.arima function in
forecast package. After fitting residuals at each grid in space, the auto
correlations are still significant ( but < 0.2). This make me think that the
data
2008 May 15
2
How to remove autocorrelation from a time series?
Dear R users,
someone knows how to remove auto-correlation from a frequencies time series?
I've tried by differencing (lag 1) the cumulative series (in order to have only positive numbers) , but I can't remove all auto-correlation.
If it's useful I can send my db.
x <- # autocorrelated series
new1<-cumsum(x)
new2<-diff(new1,lag=1,differences = 1)
acf(new2) #
2010 Jul 06
1
acf
Hi list,
I have the following code to compute the acf of a time series
acfresid <- acf(residfit), where residfit is the series
when I type acfresid at the prompt the follwoing is displayed
Autocorrelations of series ?residfit?, by lag
0.0000 0.0833 0.1667 0.2500 0.3333 0.4167 0.5000 0.5833 0.6667 0.7500 0.8333
1.000 -0.015 0.010 0.099 0.048 -0.014 -0.039 -0.019 0.040 0.018