Displaying 20 results from an estimated 6000 matches similar to: "conservative robust estimation in (nonlinear) mixed models"
2005 Dec 14
3
glmmADMB: Generalized Linear Mixed Models using AD Model Builder
Dear R-users,
Half a year ago we put out the R package "glmmADMB" for fitting
overdispersed count data.
http://otter-rsch.com/admbre/examples/glmmadmb/glmmADMB.html
Several people who used this package have requested
additional features. We now have a new version ready.
The major new feature is that glmmADMB allows Bernoulli responses
with logistic and probit links. In addition there
2009 May 26
2
(OT) Does pearson correlation assume bivariate normality of the data?
Dear all,
The other day I was reading this post [1] that slightly surprised me:
"To reject the null of no correlation, an hypothsis test based on the
normal distribution. If normality is not the base assumption your
working from then p-values, significance tests and conf. intervals
dont mean much (the value of the coefficient is not reliable) " (BOB
SAMOHYL).
To me this implied that in
2005 Oct 13
3
Do Users of Nonlinear Mixed Effects Models Know Whether Their Software Really Works?
Do Users of Nonlinear Mixed Effects Models Know
Whether Their Software Really Works?
Lesaffre et. al. (Appl. Statist. (2001) 50, Part3, pp 325-335)
analyzed
some simple clinical trials data using a logistic random effects
model. Several packages and methods MIXOR, SAS NLMIXED were employed.
They reported obtaining very different parameter estimates and
P
2005 Aug 23
1
Robust M-Estimator Comparison
Hello,
I'm learning about robust M-estimators right now and had settled on the
"Huber Proposal 2" as implemented in MASS, but further reading made clear,
that at least 2 further weighting functions (Hampel, Tukey bisquare) exist.
In a post from B.D. Ripley going back to 1999 I found the following quote:
>> 2) Would huber() give me results that are similar (i.e., close
2005 Jun 17
0
glmmADMB: Mixed models for overdispersed and zero-inflated count data in R
Dear R-users,
Earlier this year I posted a message to this list regarding
negative binomial mixed models in R. It was suggested that
the program I had written should be turned into an R-package.
This has now been done, in collaboration with David Fournier
and Anders Nielsen.
The R-package glmmADMB provides the following GLMM framework:
- Negative binomial or Poisson responses.
- Zero-inflation
2006 Mar 30
0
Robust measures of goodness of fit?
Dear all,
I have been using rlm() for robust regression. Could someone please
suggest an appropriate measure of goodness-of-fit [1]? All I've found
after trawling the web, literature databases, and previous r-help posts,
is the "robust R^2" on pp. 362-363 of the S-plus manual, which is
available at
http://web.mit.edu/afs/athena/software/splus_v7.0/www/statman1.pdf
(7.57 MB)
2010 Mar 11
2
Robust estimation of variance components for a nested design
One of my colleagues has a data set from a two-level nested design from
which we would like to estimate variance components. But we'd like some
idea of what the inevitable outliers are doing, so we were looking for
something in R that uses robust (eg Huber) treatment and returns robust
estimates of variance.
Nothing in my collection of R robust estimation packages (robust,
robustbase and MASS
2009 Aug 28
1
Help with glmer {lme4) function: how to return F or t statistics instead of z statistics.
Hi,
I'm new to R and GLMMs, and I've been unable to find the answers to my
questions by trawling through the R help archives. I'm hoping someone
here can help me.
I'm running an analysis on Seedling survival (count data=Poisson
distribution) on restoration sites, and my main interest is in
determining whether the Nutrients (N) and water absorbing polymer Gel
(G) additions to the
2006 Sep 06
1
Help on estimated variance in lme4
Dear all,
I get an error message when I run my model and I am not sure what to do
about it.
I try to determine what factors influence the survival of voles. I use a
mixed-model because I have several voles per site (varying from 2 to 19
voles).
Here is the model:
###
fm5 <-lmer(data=cdrgsaou2,
alive~factor(pacut)+factor(agecamp)+factor(sex)+ResCondCorp+(1|factor(cdrgsa
ou2$ids)),
2008 Apr 03
0
lmer function :method="AGQ" glmmADMB
The freely available R package glmmADMB can do Adaptive
Gaussian Quadrature for this type of model,
since it is built using AD Model Builder's random effects
module which incorporates this feature.
There is now a beta version of the software for
people using R on the Mac intel platform.
http://otter-rsch.com/admbre/examples/glmmadmb/glmmADMB.html
Cheers,
Dave
--
David A. Fournier
2006 Jun 06
1
[OFF] The "best" tool for a space-temporal analyses?
Hi,
I try to make an analyses to discover what is the time that an area begin to
have spacial autocorrelation. And after, what is the number of individuals
responsible for this autocorrelation.
The main idea is to discover if exist a contamination of a quadrat from others
quadrats and how is the population needed to make this contamination.
This is very common to use automata to simulate
2006 Sep 11
3
Extracting overdispersion estimates from lmer amd glm objects
Dear list,
I am needing to extract the estimate of overdispersion (deviance / residual degrees of freedom or c-hat) from multiple model objects - so they can then be used to compare the extent of overdispersion among alternative models as well as calculate qausi-AIC values. I have been unable to do this, despite consulting a number of manuals and searching the R-help. I am imaging that in
2007 Feb 12
1
lmer and estimation of p-values: error with mcmcpvalue()
Dear all,
I am currently analyzing count data from a hierarchical design, and I?ve
tried to follow the suggestions for a correct estimation of p-values as
discusssed at R-Wiki
(http://wiki.r-project.org/rwiki/doku.php?id=guides:lmer-tests&s=lme%20and%20aov).
However, I have the problem that my model only consists of parameters
with just 1 d.f. (intercepts, slopes), so that the
2011 Feb 28
1
Robust variance estimation with rq (failure of the bootstrap?)
I am fitting quantile regression models using data collected from a
sample of 124 patients. When modeling cross-sectional associations, I
have noticed that nonparametric bootstrap estimates of the variances
of parameter estimates are much greater in magnitude than the
empirical Huber estimates derived using summary.rq's "nid" option.
The outcome variable is severely skewed, and I am
2019 Dec 24
2
December LLVM bay-area social is this Thursday!
Oof. :(
Offhand, I can’t think of any place in particular. As one might imagine,
accommodating 50+ people isn’t always super easy for places to do.
Suggestions welcome!
On Tue, Dec 24, 2019 at 10:27 AM Sean Silva <chisophugis at gmail.com> wrote:
> It looks like Tied House will be shutting down :( Do we have a replacement
> venue?
>
>
>
2008 Aug 27
4
[releng_7 tinderbox] failure on amd64/amd64
TB --- 2008-08-27 11:26:00 - tinderbox 2.3 running on freebsd-stable.sentex.ca
TB --- 2008-08-27 11:26:00 - starting RELENG_7 tinderbox run for amd64/amd64
TB --- 2008-08-27 11:26:00 - cleaning the object tree
TB --- 2008-08-27 11:26:30 - cvsupping the source tree
TB --- 2008-08-27 11:26:30 - /usr/bin/csup -r 3 -g -L 1 -h localhost -s /tinderbox/RELENG_7/amd64/amd64/supfile
TB --- 2008-08-27
2004 Nov 08
2
Nonlinear weighted least squares estimation
Hi there,
I'm trying to fit a growth curve to some data and need to use a weighted least squares estimator to account for heteroscedasticity in the data. A weights argument is available in nls that would appear to be appropriate for this purpose, but it is listed as 'not yet implemented'. Is there another package which could implement this procedure?
Regards,
Robert Brown
2010 Oct 18
1
Data contamination
Dear experts,
Helps are badly needed.
I'm trying to generate a panel data with error term from N(0,1) and alpha
from U(0,20).Explanatory variables are from multivariate std normal distn.
Problem arised when I tried to contaminate the data in Y by adding
additional term from N(50,1). I ask the computer to choose 5 random data
from Y by using the command runif(5,1,50) since we have 50 data
2003 Sep 04
2
laplace transform
Dear users,
is anybody of you aware of a R command to perform laplace transform or
even its inversion?
Thank you very much.
Luca
2015 Mar 24
2
[LLVMdev] RFC - Improvements to PGO profile support
> On Mar 24, 2015, at 12:08 PM, Xinliang David Li <davidxl at google.com> wrote:
>
> On Tue, Mar 24, 2015 at 10:54 AM, Bob Wilson <bob.wilson at apple.com> wrote:
>>
>>> On Mar 24, 2015, at 10:53 AM, Diego Novillo <dnovillo at google.com> wrote:
>>>
>>> On Tue, Mar 24, 2015 at 1:48 PM, Bob Wilson <bob.wilson at apple.com> wrote: