Displaying 20 results from an estimated 9000 matches similar to: "detecting autocorrelation structure in panel data"
2011 Dec 01
1
efficient ways to dynamically grow a dataframe
Hi,
I'm trying to write a small microsimulation in R: that is, I have a
dataframe with info on N individuals for the base-year and I have to
grow it dynamically for T periods:
df = data.frame(
id = 1:N,
x =....
)
The most straightforward way to solve the problem that came to my mind
is to create for every period a new dataframe:
for(t in 1:T){
for(i in 1:N){
row = data.frame(
id =
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) #
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
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
2009 Aug 25
1
Autocorrelation and t-tests
Hi,
I have two sets of data for a given set of (non-lattice) locations. I would
like to know whether the two are significantly different. This would be
simple enough if it wasn't for the fact that the data is spatially
autocorrelated. I have come across several possible solutions (including
Cliff & Ord which however appears to be for gridded data), or using gls.
However, they don't
2008 Aug 14
1
autocorrelation in gams
Hi,
I am looking at the effects of two explanatory variables on chlorophyll.
The data are an annual time-series (so are autocorrelated) and the
relationships are non-linear. I want to account for autocorrelation in
my model.
The model I am trying to use is this:
Library(mgcv)
gam1 <-gam(Chl~s(wintersecchi)+s(SST),family=gaussian,
na.action=na.omit, correlation=corAR1(form =~
2010 Apr 17
2
interpreting acf plot
Hello,
I am attending a course in Computational Statistics at ETH and in one of the assignments I am asked to prove that a time series is not autocorrelated using the R function "acf".
I tried out the acf function with the given data, according to what I found here: http://landshape.org/enm/options-for-acf-in-r/ this test data does not look IID but rather shows some trends so how can I
2011 Feb 22
1
Adjusting for autocorrelation in a panel model
I am working with panel data. I am using the plm package to do this.
I would like to do be able to adjust for autocorrelation, as one does with
glm models and correlation structures (eg corr=corARMA(q=4)) . In
particular, I want to employ MA(4) error structure.
Is there a way of doing this with the plm package?
(Note: I do not really want to use the pggls function for various
2005 Feb 10
2
correcting for autocorrelation in models with panel data?
Hi
I have some panel data for the 50 US states over about 25 years, and I
would like to test a simple model via OLS, using this data. I know how
to run OLS in R, and I think I can see how to create Panel Corrected
Standard Errors using
http://jackman.stanford.edu/classes/350C/pcse.r
What I can't figure out is how to correct for autocorrelation over
time. I have found a lot of R stuff on
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
2010 Dec 27
0
Heteroskedasticity and autocorrelation of residuals
Hello everyone,
I'm working on a current linear model Y = a0 + a1* X1 + ... + a7*X7 +
residuals. And I know that this model presents both heteroskedasticity
(tried Breusch-Pagan test and White test) and residuals autocorrelation
(using Durbin Watson test). Ultimately, this model being meant to be used
for predictions, I would like to be able to remove this heteroskedasticity
and residuals
USING TOBIT OR WHAT ALTERNATIVE WHEN DATA ARE PANEL AND HETEROSKEDASTIC AND PROBABLY AUTOCORRELATED?
2008 Aug 28
0
USING TOBIT OR WHAT ALTERNATIVE WHEN DATA ARE PANEL AND HETEROSKEDASTIC AND PROBABLY AUTOCORRELATED?
Please, I seek expertise and advice, possibly leads to R packages or
stats literature.
My data: measurements of economic variables for each county of
California over 37 years.
My dependent variable is square feet of office floor space permitted to
be added in a county.
Independent variables include for example change in number of office
jobs in same county same year (and lagged years).
2007 Mar 13
1
AR(1) and gls
Hi there,
I am using gls from the nlme library to fit an AR(1) regression model.
I am wondering if (and how) I can separate the auto-correlated and random
components of the residuals? Id like to be able to plot the fitted values +
the autocorrelated error (i.e. phi * resid(t-1)), to compare with the
observed values.
I am also wondering how I might go about calculating confidence (or
2010 Apr 29
1
a question on autocorrelation acf
Hi R users,
where can I find the equations used by acf function to calculate
autocorrelation? I think I misunderstand acf. Doesn't acf use following
equation to calculate autocorrelation?
[image: R(\tau) = \frac{\operatorname{E}[(X_t - \mu)(X_{t+\tau} -
\mu)]}{\sigma^2}\, ,]
If it does, then the autocorrelation of a sine function should give a
cosine; however, the following code gives a
2008 Oct 08
0
partial autocorrelation plots ACF type=p
Dear users,
I have two continuous variables which are two different measures taken each
year from 1975 to 2005. I want to see if the two variables are correlated
but need to take into account the fact that they are a time series. I have
been following an example from 'The R Book' where you plot the ACF:
par(mfrow=c(1,1)
acf(cbind(x,y))
and this appeared to work fine, producing four
2007 Sep 12
2
Nested anova with unbalanced design and corrected sample size for spatial autocorrelation
Hello all,
This may be a simple question to answer, but I'm a little bit stumped with
respect to the calculation of the F statistics in nested anovas with
unbalanced design in R.
In my case, I have 11 vegetation transects (with 1000 10cmx10cm squares),
where we estimated shrub cover. We have two different treatments: wildfire
(4 transects) and prescribed burning (7 transects) and we want to
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 =
2012 Jan 09
1
Autocorrelation values? How to extract?
Hi,
I am attempting to correct my models p-values due to temporal
autocorrelations. It is not possible to model the correlation, so I have to
make do with the p-value correction. I am feeling a bit thick here....I
cannot get the autocorrelation values. What is the argument?
My aim is to multiply the dependent variable autocorrelation with the
independent variable autocorrelation and then
2008 Jul 06
1
Different Autocorrelation using R and other softwares
Dear All,
Would like to ask the inconsistency in the autocorrelation from R with
SPSS/Minitab. I have tried a dataset x with 20 data (1-20) and ask R to give
the autocorrelation of different lags using the command < acf(x,
lag.max=100, type = "correlation"), However while SPSS and Minitab give the
same answers (0.85 for lag1), R gives 0.3688 which is much smaller.
Obviously, the
2010 May 20
2
writing autocorrelation and partial auto correlation functions to a file
Dear All,
I am very new to T. I need to fit a ARIMA model to my time
series. So I found the auto correlation functions and partial auto
correlation function in R. Now I want to save these valuse along with the
significance levels to a file. How to do that?. I tried some function in R
like write.table but returns an error "cannot coerce class "acf" into a