Displaying 20 results from an estimated 2000 matches similar to: "coxph - weights- robust SE"
2003 Jun 12
1
What PRECISELY is the dfbetas() or lm.influence()$coef ?
Hello. I want to get the proper influence function for the glm
coefficients in R. This is supposed to be inv(information)*(y-yhat)*x. So
I am wondering what is the exact mathematical formula for the output that
the functions:
dfbeta() OR lm.influence()$coefficients
return for a glm model. I am confused because:
1. Their columns don't sum to zero as influences should.
2. They
2007 Dec 14
1
problem with coxph
Hi everyone,
I encountered a problem using the coxph function for the conditional
logistic regression. I am trying to do some simulations and I really don’t
understand a mistake which happened maybe only 1 time among more than
1,000 simulations.
What appeared on the screen is the following:
Error in fitter(X,Y,strats,offset,init,control,weights=weights,:
NA/NaN/Inf in a foreign function (arg
2003 Jul 12
1
Problem with library "car"
I am using the Unix version of R (version 1.7.0), installed via fink on a G4
Macintosh. I recently upgraded from version 1.6.0 and found that the "car"
library now has a problem:
---Begin transcript---
>library(car)
Attaching package 'car':
The following object(s) are masked from package:base :
dfbeta dfbeta.lm dfbetas dfbetas.lm hatvalues hatvalues.lm
2011 Apr 29
1
logistic regression with glm: cooks distance and dfbetas are different compared to SPSS output
Hi there,
I have the problem, that I'm not able to reproduce the SPSS residual
statistics (dfbeta and cook's distance) with a simple binary logistic
regression model obtained in R via the glm-function.
I tried the following:
fit <- glm(y ~ x1 + x2 + x3, data, family=binomial)
cooks.distance(fit)
dfbetas(fit)
When i compare the returned values with the values that I get in SPSS,
2009 Nov 13
1
dfbetas vs dfbeta
Hi, I've looked around but can't find a clear answer to the difference for
these two? Any help?
Thanks!
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2001 Apr 28
9
two new packages
I've prepared preliminary versions of two packages that I plan eventually
to contribute to CRAN:
car (for "Companion to Applied Regression") is a package that provides a
variety of functions in support of linear and generalized linear models,
including regression diagnostics (e.g., studentized residuals, hat-values,
Cook's distances, dfbeta, dfbetas, added-variable plots,
2001 Apr 28
9
two new packages
I've prepared preliminary versions of two packages that I plan eventually
to contribute to CRAN:
car (for "Companion to Applied Regression") is a package that provides a
variety of functions in support of linear and generalized linear models,
including regression diagnostics (e.g., studentized residuals, hat-values,
Cook's distances, dfbeta, dfbetas, added-variable plots,
2001 Apr 28
9
two new packages
I've prepared preliminary versions of two packages that I plan eventually
to contribute to CRAN:
car (for "Companion to Applied Regression") is a package that provides a
variety of functions in support of linear and generalized linear models,
including regression diagnostics (e.g., studentized residuals, hat-values,
Cook's distances, dfbeta, dfbetas, added-variable plots,
2009 Feb 20
1
Diagnostics for single-observation deletion in Cox models
Hi,
Storer and Crowley (JASA 1985) presented an approach for approximating the
changes in maximum partial-likelihood parameter estimates for the Cox model
when a single observation is deleted. Is there an R implementation of this
approach?
Any help is greatly appreciated. Thanks.
Best,
Ravi.
----------------------------------------------------------------------------
-------
Ravi
2006 Feb 16
2
how to retrieve robust se in coxph
Hi,
I am using coxph in simulations and I want to store the "robust se" (or
"se2" in frailty models) for each replicate. Is there a function to retrieve
it, like vcov() for the variance estimate? Thanks!
Lei Liu
Assistant Professor
Division of Biostatistics and Epidemiology
Dept. of Public Health Sciences
School of Medicine
University of Virginia
3181 Hospital West
2009 Jan 14
1
dfbetas without intercept
Hello
I am running a regression without the intercept, and want to compute dfbetas. How do I do this? The dfbetas function only works when the intercept is included in the model.
Regards
K
[[alternative HTML version deleted]]
2013 May 01
1
Trouble with methods() after loading gdata package.
Greetings to r-help land.
I've run into some program crashes and I've traced them back to methods()
behavior
after the package gdata is loaded. I provide now a minimal re-producible
example. This seems bugish to me. How about you?
dat <- data.frame(x = rnorm(100), y = rnorm(100))
lm1 <- lm(y ~ x, data = dat)
methods(class = "lm")
## OK so far
library(gdata)
2009 Oct 10
2
easy way to find all extractor functions and the datatypes of what they return
Am I asking for too much:
for any object that a stat proc returns ( y <- lm( y~x) , etc ) ) , is there
a super convenient function like give_all_extractors( y ) that lists all
extractor functions , the datatype returned , and a text descriptor
field ("pairwisepval" "lsmean" etc)
That would just be so convenient.
What are my options for querying an object so that I can
2006 May 07
1
model selection, stepAIC(), and coxph() (fwd)
Hello,
My question concerns model selection, stepAIC(), add1(), and coxph().
In Venables and Ripley (3rd Ed) pp389-390 there is an example of using
stepAIC() for the automated selection of a coxph model for VA lung cancer
data.
A statistics question: Can partial likelihoods be interpreted in the same
manner as likelihoods with respect to information based criterion and
likelihood ratio tests?
2010 Feb 10
2
Total least squares linear regression
Dear all,
After a thorough research, I still find myself unable to find a function
that does linear regression of 2 vectors of data using the "total least
squares", also called "orthogonal regression" (see :
http://en.wikipedia.org/wiki/Total_least_squares) instead of the
"ordinary least squares" method. Indeed, the "lm" function has a
2009 Feb 24
1
Box.test reference correction (PR#13554)
Full_Name: Peter Solymos
Version: 2.8.1
OS: Windows
Submission from: (NULL) (129.128.141.92)
The help page of the Box.test function (stats) states that the Ljung-Box test
was published in:
Ljung, G. M. and Box, G. E. P. (1978), On a measure of lack of fit in time
series models. Biometrika 65, 553--564.
The page numbers are incorrect. The correct citation should be as follows:
Ljung, G. M.
2010 Feb 21
1
tests for measures of influence in regression
influence.measures gives several measures of influence for each
observation (Cook's Distance, etc) and actually flags observations
that it determines are influential by any of the measures. Looks
good! But how does it discriminate between the influential and non-
influential observations by each of the measures? Like does it do a
Bonferroni-corrected t on the residuals identified by
2009 Apr 11
2
who happenly read these two paper Mohsen Pourahmadi (biometrika1999, 2000)
http://biomet.oxfordjournals.org/cgi/reprint/86/3/677 biometrika1999
http://biomet.oxfordjournals.org/cgi/reprint/94/4/1006 biometrika2000
Hi All:
I just want to try some luck.
I am currenly working on my project,one part of my project is to
reanalysis the kenward cattle data by using the method in Mohsen's paper,but
I found I really can get the same or close output as he did,so,any
2006 Oct 26
3
Measurements of 3000 criminals
Hallo everyone,
excuse me if this is not a genuine R question but I do not know where to
ask else.
Referring to e.g.
https://stat.ethz.ch/pipermail/r-help/2004-December/062114.html
I wonder if these measurements of 3000 criminals (raw data) are
available anywhere. At least I didn't find them in the R datasets
package or by means of Google. What I did find was a table of
frequencies of
2010 Mar 06
1
Robust SE for lrm object
I'm trying to obtain the robust standard errors for a multinomial ordered logit model:
mod6 <- lrm(wdlshea ~ initdesch + concap + capasst + qualrat + terrain,data=full2)
The model is fine but when I try to get the RSE I get an error.
coeftest(mod6, vcov = vcovHAC(mod6))
Error in match.arg(type) :
'arg' should be one of “ordinary”, “score”, “score.binary”, “pearson”,