Displaying 20 results from an estimated 30000 matches similar to: "Syntax for getting covariance matrix"
2010 Jul 28
1
Variance-covariance matrix from GLM
Hello,
Is there a way to obtain the variance-covariance matrix of the estimated parameters from GLM?
my.glm<-glm(mat ~X,family = binomial, data =myDATA)
out1<-predict(my.glm,se.fit = TRUE)
std<-out1$se.fit
se.fit is for getting the standard errors of the estimated parameters (\betas). Is there a way to get the variance-covariance matrix of the estimated parameters?
Many thanks,
2011 Jan 23
1
extract score vector and covariance matrix in glm package
Hello
I am running a project but I encounter a problem . I would be happy
to receive help :
problem:
I have a binary dependent variable and some covariates logit(y)=a+bx+cz .
I want to estimate the score vectors and their covariance by the usage of
logit function and so glm in R .The vlaue of one of the coefficient (
like b) is known previously and I want to extract a and c and covariance
2006 Jun 02
3
lm() variance covariance matrix of coefficients.
Hi,
I am running a simple linear model with (say) 5 independent variables. Is
there a simple way of getting the variance-covariance matrix of the
coeffcient estimates? None of the values of the lm() seem to provide this.
Thanks in advance,
Ritwik Sinha
rsinha@darwin.cwru.edu
Grad Student
Case Western Reserve University
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2012 Oct 13
1
hep on arithmetic covariance conversion to log-covariance
Dear All,
is there a function in R that would help me convert a covariance matrix built based on arithmetic returns to a covariance matrix from log-returns?
As an example of the means and covariance from arithmetic:
mu <-c(0.094,0.006,1.337,1.046,0.263)
sigma
2007 Oct 29
6
covariance matrix of the regression coefficients
Greetings,
Cohen, Cohen, West, and Aiken 2003 (Applied Multiple Regression-Correlation
Analysis for the Behavioral Sciences, Third Edition) on page 273 state the
covariance matrix of the regression coefficients is provided by standard
programs for multiple regression, including SAS, SPSS, and SYSTAT. How can
it be calculated with R. Thank you very much.
pbm
Peter B. Mandeville
cel:
2006 Oct 12
2
how to get the variance-covariance matrix/information of alpha and beta after fitting a GLMs?
Dear friends,
After fitting a generalized linear models ,i hope to get the variance of
alpha,variance of beta and their covariance, that is , the
variance-covariance matrix/information of alpha and beta , suppose *B* is
the object of GLMs, i use attributes(B) to look for the options ,but can't
find it, anybody knows how to get it?
> attributes(B)
$names
[1] "coefficients"
2019 Feb 19
1
mle (stat4) crashing due to singular Hessian in covariance matrix calculation
Hi, R developers.
when running mle inside a loop I found a nasty behavior. From time to
time, my model had a degenerate minimum and the loop just crashed. I
tracked it down to "vcov <- if (length(coef)) solve(oout$hessian)" line,
being the hessian singular.
Note that the minimum reached was good, it just did not make sense to
calculate the covariance matrix as the inverse of a
2004 Jan 29
2
Calculating/understanding variance-covariance matrix of logistic regression (lrm $var)
Hallo!
I want to understand / recalculate what is done to get
the CI of the logistic regression evaluated with lrm.
As far as I came back, my problem is the
variance-covariance matrix fit$var of the fit
(fit<-lrm(...), fit$var). Here what I found and where
I stucked:
-----------------
library(Design)
# data
D<-c(rep("a", 20), rep("b", 20))
V<-0.25*(1:40)
V[1]<-25
2005 Feb 11
1
how ot get covariance matrix from survreg
I have a question, I generated some data and tried survreg to analyze
them, but here, I want to get the covariance matrix of the coefficients.
I know how to get corr from survreg, say, summary(f,corr=T), but how to
get covariance matrix of the coefficient ?
can I put them in a matrix and output ?
thanks
below is what I did
<mailto:r-help@stat.math.ethz.ch>
n=100; beta=1.0
2008 Aug 11
1
variance covariance matrix of parameter estimate using nlrq
In "lm" command, we can use "vcov" option to get variance-covariance matrix. Does anyone know how to get variance-covariance matrix in nlrq?
Thanks,
Kate
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2011 Sep 28
1
Robust covariance matrix with NeweyWest()
Dear R-users,
I would like to compute a robust covariance matrix of two series of realizations of random variables:
###Begin Example###
data <- cbind(rnorm(100), rnorm(100))
model <- lm(data ~ 1)
vcov(model)
library(sandwich)
NeweyWest(model) #produces an error
###End Example###
NeweyWest() produces an error but sandwich(), vcovHAC(), kernHAC, weave(),... do not produce any errors. It
2011 Feb 24
0
var:covariance matrix from glm using logit function
I want to predict a set of proportions from a linear regression using glm.
The model includes a logit link. However I want to extract the
variance:covariance matrix among the predicted proportions rather than
on the logit scale.
Is there a way to do this using Vcov or a similar package in R?
Thanks
Chris
2005 Aug 25
4
covariance matrix under null
Hello
I am fitting a Cox PH model using the function coxph(). Does anyone know how
to obtain the estimate of the covariance matrix under the null hypothesis.
The function coxph.detail() does not seem to be useful for this purpose.
Thanks,
KD.
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2006 Oct 14
2
regression analyses using a vector of means and a variance-covariance matrix
R 2.2.0
windows XP
How can I perform a regression analyses using a vector of means, a
variance-covariance matrix? I looked at the help screen for lm and did
not see any option for using the afore mentioned structures as input to
lm.
Thanks,
John
John Sorkin M.D., Ph.D.
Chief, Biostatistics and Informatics
Baltimore VA Medical Center GRECC,
University of Maryland School of Medicine Claude D.
2003 Apr 23
3
regression parms var-cov matrix
Win2k, R1.6.2.
I've been using Splus 6.1 and wanted to try the same
regression analysis in R. Using "names( blah.lm )"
in R yields
[1] "coefficients" "residuals" "effects" "rank"
[5] "fitted.values" "assign" "qr" "df.residual"
[9] "xlevels"
2006 Nov 25
1
hausman Test
Does anyone know how to do an Hausman test?
I?ve estimate a modell (some alternatives) with clogit an wanted to test the
IIA test (Independence of Irrelevant
Alternatives) after estimating a multinomial logit model?
Thank you
2012 Mar 19
1
glm: getting the confidence interval for an Odds Ratio, when using predict()
Say I fit a logistic model and want to calculate an odds ratio between 2
sets of predictors. It is easy to obtain the difference in the predicted
logodds using the predict() function, and thus get a point-estimate OR. But
I can't see how to obtain the confidence interval for such an OR.
For example:
model <- glm(chd ~age.cat + male + lowed, family=binomial(logit))
pred1 <-
2008 May 29
1
appropriate covariance matrix for multiple nominal exogenous and multiple continuous endogenous variables in SEM
Hi,
I would like to use the sem package to perform a path analysis (no
latent variables) with a mixture of 2 nominal exogenous, 1 continuous
exogenous, and 4 continuous endogenous variables. I seek advice as to
how to calculate the appropriate covariance matrix for use with the sem
package.
I have read through the polycor package, and am confused as to the use
of "numeric" for
2010 Oct 18
1
Looking for covariance function -OR- how do you search
Hello everyone.,
I am looking for a covariance function this not the first time I have this type
of problem (to find which function does something). I try in google with "R cran
covariance function" but usually this ends with different results that do not
help me that much.
Could you please try to advice me how to search for what function implements the
functionality you want.
2007 Sep 26
1
Accessing the fixed- and random-effects variance-covariance matrices of an nlme model
I would appreciate confirmation that the function vcov(model.nlme)
gives the var-cov matrix of the fixed effects in an nlme model.
Presumably the random-effects var-cov matrix is given by cov(ranef
(model.nlme)?
Rob Forsyth