Displaying 20 results from an estimated 4000 matches similar to: "Parallel Processing and Linear Regression"
2008 Jul 21
1
Large number of dummy variables
Hello,
I'm trying to run a regression predicting trade flows between importers and
exporters. I wish to include both year-importer dummies and year-exporter
dummies. The former includes 1378 levels, and the latter includes 1390
levels. I have roughly 100,000 total observations.
When I'm using lm() to run a simple regression, it give me a "cannot
allocate ___" error.
2006 Apr 25
5
Heteroskedasticity in Tobit models
Hello,
I've had no luck finding an R package that has the ability to estimate a
Tobit model allowing for heteroskedasticity (multiplicative, for example).
Am I missing something in survReg? Is there another package that I'm
unaware of? Is there an add-on package that will test for
heteroskedasticity?
Thanks for your help.
Cheers,
Alan Spearot
--
Alan Spearot
Department of Economics
2009 Dec 02
1
Incorporating the results of White's HCCM into a linear regression:
Using hccm() I got a heteroscedasticity correction factor on the diagonal of
the return matrix, but I don't know how to incorporate this into my linear
model:
METHOD 1:
> OLS1 <- lm(formula=uer92~uer+low2+mlo+spec+degree+hit)
Coefficients:
Estimate Std. Error t value Pr(>|t|)
(Intercept) -0.0623377 0.0323461 -1.927 0.057217 .
uer 0.2274742 0.0758720
2006 Apr 28
1
function for linear regression with White std. errors
I would like to know if there is a function that will run a linear
regression and report the White (heteroscedasticity consistent) std.
errors.
I've found the hccm() function in the car library, but that just gives
me the White covariance matrix. I'd like to be able to see the White
std. errors without having to do much more work, if possible.
Thanks,
Brian
2003 Mar 24
2
Robust standard errors
I am trying to calculate robust standard errors for a logit model. I
installed the package "car" and tried using hccm.default, but that
required an lm object. Is there some way to do a similar operation for a
glm object?
x <- hccm.default(glm(winner ~ racebl + racehi + raceas + inchi + incmed +
edhs + edcol + edba + agec1 + agec4 + sex + margin + regla + regbay +
regsc +
2008 Sep 04
2
Correct for heteroscedasticity using car package
Dear all,
Sorry if this is too obvious.
I am trying to fit my multiple regression model using lm()
Before starting model simplification using step() I checked whether the
model presented heteroscedasticity with ncv.test() from the CAR package.
It presents it.
I want to correct for it, I used hccm() from the CAR package as well and
got the Heteroscedasticity-Corrected Covariance Matrix.
I am not
2006 Dec 24
1
extend summary.lm for hccm?
dear R experts:
I wonder whether it is possible to extend the summary method for the
lm function, so that it uses an option "hccm" (well, model "hc0"). In
my line of work, it is pretty much required in reporting of almost all
linear regressions these days, which means that it would be very nice
not to have to manually library car, then sqrt the diagonal, and
recompute
2007 Jan 01
1
advice on semi-serious attempt to extend summary
Dear R wizards:
I am trying (finally) to build a function that might be useful to
others. In particular, I want to create a summary.lme (extended lm)
method that [a] adds normalized coefficients and [b] white
heteroskedasticity adjusted se's and T's. I believe I already know
how to do the programming to do these two, at least in simple
unweighted cases. Now my challenges are just [1]
2007 Aug 16
4
Linear models over large datasets
I'd like to fit linear models on very large datasets. My data frames
are about 2000000 rows x 200 columns of doubles and I am using an 64
bit build of R. I've googled about this extensively and went over the
"R Data Import/Export" guide. My primary issue is although my data
represented in ascii form is 4Gb in size (therefore much smaller
considered in binary), R consumes about
2010 May 10
2
Robust SE & Heteroskedasticity-consistent estimation
Hi,
I'm using maxlik with functions specified (L, his gradient & hessian).
Now I would like determine some robust standard errors of my estimators.
So I 'm try to use vcovHC, or hccm or robcov for example
but in use one of them with my result of maxlik, I've a the following
error message :
Erreur dans terms.default(object) : no terms component
Is there some attributes
2004 Dec 02
1
[Bug 958] patch to support GSI GSSAPI mechanism
http://bugzilla.mindrot.org/show_bug.cgi?id=958
Summary: patch to support GSI GSSAPI mechanism
Product: Portable OpenSSH
Version: 3.9p1
Platform: All
URL: http://grid.ncsa.uiuc.edu/ssh/
OS/Version: All
Status: NEW
Severity: enhancement
Priority: P2
Component: Miscellaneous
2009 Feb 19
1
Questions about biglm
Hello folks,
I am very excited to have discovered R and have been exploring its
capabilities. R's regression models are of great interest to me as my
company is in the business of running thousands of linear regressions
on large datasets.
I am using biglm to run linear regressions on datasets that are as
large as several GB's. I have been pleasantly surprised that biglm
runs the
2008 Aug 17
1
package building problem on windows
Hi,
I'm trying to compile the package biglm, but when I build it with R
CMD build biglm, it failed :
C:\LOCAL\c-dutang\code\R\biglm2>R CMD build biglm
* checking for file 'biglm/DESCRIPTION' ... OK
* preparing 'biglm':
* checking DESCRIPTION meta-information ...C:/DOCUME~1/c-dutang/Local:
Can't op
n C:/DOCUME~1/c-dutang/Local: No such file or directory
2010 Oct 31
1
biglm: how it handles large data set?
I am trying to figure out why 'biglm' can handle large data set...
According to the R document - "biglm creates a linear model object that uses
only p^2 memory for p variables. It can be updated with more data using
update. This allows linear regression on data sets larger than memory."
After reading the source code below? I still could not figure out how
'update'
2009 Mar 17
1
exporting s3 and s4 methods
If a package defined an S3 generic and an S4 generic for the same function (so as to add methods for S4 classes to the existing code), how do I set up the namespace to have them exported?
With
import(stats)
exportMethods(bigglm)
importClassesFrom(DBI)
useDynLib(biglm)
export(biglm)
export(bigglm)
in NAMESPACE, the S3 generic is not exported.
> methods("bigglm")
[1] bigglm.RODBC*
2011 Jul 25
1
biglm() and NeweyWest()
Dear all,
I am working on a large dataset and need to use biglm() to perform OLS
regressions. I have detected significant ARCH effects which I try to account
for using the Newey-West correction.
So far, I have worked with NeweyWest() in the sandwich package. NeweyWest()
however seems to be unable to handle an object of class "biglm".
Looking into the code, I figured out that
2010 Jun 15
1
help biglm.big.matrix; problem with weights
Hello colleagues,
I have tried to use the package biglm. I want to specify a
multivariate regression with a weight.
I have imported a large dataset with the library(bigmemory). I load
the library (biglm) and specified a regression with a weight. But I
get everytime a error message like ?object not found? or ?`weights'
must be a formula? or "error in eval(expr, envir, enclos)". I
2006 Jan 05
2
Wald tests and Huberized variances (was: A comment about R:)
On Wed, 4 Jan 2006, Peter Muhlberger wrote:
One comment in advance: please use a more meaningful subject. I would have
missed this mail if a colleague hadn't pointed me to it.
> I'm someone who from time to time comes to R to do applied stats for social
> science research.
[snip]
> I would also prefer not to have to work through a
> couple books on R or S+ to learn how to
2009 Jul 03
2
bigglm() results different from glm()
Hi Sir,
Thanks for making package available to us. I am facing few problems if
you can give some hints:
Problem-1:
The model summary and residual deviance matched (in the mail below) but
I didn't understand why AIC is still different.
> AIC(m1)
[1] 532965
> AIC(m1big_longer)
[1] 101442.9
Problem-2:
chunksize argument is there in bigglm but not in biglm, consequently,
2011 Nov 15
1
getting R2 (goodness of fit) result after using biglm()
Hello. I had been struggling with running linear regression using
lm() primarily because my data has a few categorical variables with at
least a thousand levels.
I tried the biglm() function and it worked.
My problem now is that i don't know how to get the R2 results. Could
someone help?
Thanks,
sean