Displaying 20 results from an estimated 900 matches similar to: "Aranda-Ornaz links for binary data"
2008 Feb 23
1
Aranda-Ordaz
Hi all,
Does anyone know R code or SAS code for Aranda-Ordaz link family?
thanks,
xiao yue
---------------------------------
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2002 Oct 22
5
Mixture of Univariate Normals
Dear list,
Can anyone provide a package or code for estimating the parameters of a
mixture of c (c >=2) univariate normal distributions?
I've tried the algorithm provided by Venables & Ripley (1999) p 263, for
the mixture of two normal, but I don't find the "ms" function in R. I've
used nls instead, but I'm not sure if it works the same.
The data I have is very
2003 Feb 19
2
GLM for Beta distribution
Hi R-help,
Is there such a thing as a function in R for fitting a GLM where the
response is distributed as a Beta distribution?
In my case, the response variable is a percentage ([0,1] and continuous).
The current glm() function in R doesn't include the Beta distribution.
Thank you for any help on this topic.
Sincerely,
Sharon K?hlmann
2012 Mar 01
2
User defined link function with extra parameters
Hello R users,
I would like to fit a generalized linear model for the binomial family
with some non standard link functions. For instance, this is the
Aranda-Ordaz link:
? = ln( ( (1 - ?)^-? - 1 )/?)
I know how to define a new link function to use with glm(), but I my
problem is that I have an extra parameter to estimate and I have no clue
how to incorporate that. Is there any way to tell
2005 Jun 16
1
mu^2(1-mu)^2 variance function for GLM
Dear list,
I'm trying to mimic the analysis of Wedderburn (1974) as cited by
McCullagh and Nelder (1989) on p.328-332. This is the leaf-blotch on
barley example, and the data is available in the `faraway' package.
Wedderburn suggested using the variance function mu^2(1-mu)^2. This
variance function isn't readily available in R's `quasi' family object,
but it seems to me
2004 Jan 08
3
Strange parametrization in polr
In Venables \& Ripley 3rd edition (p. 231) the proportional odds model
is described as:
logit(p<=k) = zeta_k + eta
but polr apparently thinks there is a minus in front of eta,
as is apprent below.
Is this a bug og a feature I have overlooked?
Here is the naked code for reproduction, below the results.
------------------------------------------------------------------------
---
version
2000 Jul 24
1
scoping problems (PR#614)
I am resubmitting this to r-bugs, since Thomas Lumley indicates that it
might be an error:
On Wed, 5 Jul 2000, Thomas Lumley wrote:
> On Wed, 5 Jul 2000, halvorsen wrote:
>
> > Hola!
> >
> > I have the following simple function:
> >
> > > testcar
> > function(pow){
> > ob <- glm(Pound~CG+Age+Vage,data=car,weights=No,
> >
2003 Jan 16
3
Overdispersed poisson - negative observation
Dear R users
I have been looking for functions that can deal with overdispersed poisson
models. Some (one) of the observations are negative. According to actuarial
literature (England & Verall, Stochastic Claims Reserving in General
Insurance , Institute of Actiuaries 2002) this can be handled through the
use of quasi likelihoods instead of normal likelihoods. The presence of
negatives is not
2007 Oct 26
5
help
hello,
please can anyone help me out. Am a new user of R
program. Am having problem
with this code below, not getting the expected
results.
1. Each m, the cumulative sum should be 1.000 but the
2nd and 3rd m returned 2.000 and 3.000
instead of 1.000.
2. to get the LCL(m) and UCL(m) for each m base on
these instructions
if out.cum > 0.025 then LCL(m)= y-1
if out.cum >0.975
2006 Jan 14
2
initialize expression in 'quasi' (PR#8486)
This is not so much a bug as an infelicity in the code that can easily
be fixed.
The initialize expression in the quasi family function is, (uniformly
for all links and all variance functions):
initialize <- expression({
n <- rep.int(1, nobs)
mustart <- y + 0.1 * (y == 0)
})
This is inappropriate (and often fails) for variance function
"mu(1-mu)".
2009 Oct 23
1
making a plot in xyplot
Hello,
I am a newbie to the lattice package in R, and I'm trying to make a plot using the xyplot function. I have repeated measures data (2 conditions) for two different groups of subjects (teens and adults).
So far, I've made a basic graph using xyplot(y ~x, group=subnum, data=mydata, type="b").
Now I would like to make all the teens' lines one color and the adults'
2009 Aug 21
2
using loglog link in VGAM or creating loglog link for GLM
I am trying to figure out how to apply a loglog link to a binomial
model (dichotomous response variable with far more zeros than ones).
I am aware that there are several relevant posts on this list, but I
am afraid I need a little more help. The two suggested approaches
seem to be: 1) modify the make.link function in GLM, or 2) use the
loglog or cloglog functions in the VGAM package.
2004 Jun 01
2
GLMM(..., family=binomial(link="cloglog"))?
I'm having trouble using binomial(link="cloglog") with GLMM in
lme4, Version: 0.5-2, Date: 2004/03/11. The example in the Help file
works fine, even simplified as follows:
fm0 <- GLMM(immun~1, data=guImmun, family=binomial, random=~1|comm)
However, for another application, I need binomial(link="cloglog"),
and this generates an error for me:
>
2009 Jan 23
4
glm binomial loglog (NOT cloglog) link
I would like to do an R glm() with
family = binomial(link="loglog")
Right now, the cloglog link exists, which is nice when the data have a
heavy tail to the left. I have the opposite case and the loglog link
is what I need. Can someone suggest how to add the loglog link onto
glm()? It would be lovely to have it there by default, and it
certainly makes sense to have the two opposite
2010 Mar 16
0
New package: ordinal
This is to announce the new R-package ?ordinal? that implements
cumulative link (mixed) models for ordinal (ordered categorical) data
(http://www.cran.r-project.org/package=ordinal/).
The main features are:
- scale (multiplicative) as well as location (additive) effects
- nominal effects for a subset of the predictors (denoted partial
proportional odds when the link is the logistic)
- structured
2010 Mar 16
0
New package: ordinal
This is to announce the new R-package ?ordinal? that implements
cumulative link (mixed) models for ordinal (ordered categorical) data
(http://www.cran.r-project.org/package=ordinal/).
The main features are:
- scale (multiplicative) as well as location (additive) effects
- nominal effects for a subset of the predictors (denoted partial
proportional odds when the link is the logistic)
- structured
2018 Aug 05
2
MASS::boxcox "object not found"
Hi there,
I wrote a function that wraps MASS::boxcox as:
bc <- function(vec) {
lam <- boxcox(lm(vec ~ 1))
lam <- lam$x[which.max(lam$y)]
(vec^lam - 1)/lam
}
When I invoke it as:
> x <- runif(20)
> bc(x)
Error in eval(predvars, data, env) : object 'vec' not found
I have googled, and rewrote the above function as:
bc <- function(vec) {
dat <<-
2018 Aug 05
2
MASS::boxcox "object not found"
Hi there,
I wrote a function that wraps MASS::boxcox as:
bc <- function(vec) {
lam <- boxcox(lm(vec ~ 1))
lam <- lam$x[which.max(lam$y)]
(vec^lam - 1)/lam
}
When I invoke it as:
> x <- runif(20)
> bc(x)
Error in eval(predvars, data, env) : object 'vec' not found
I have googled, and rewrote the above function as:
bc <- function(vec) {
dat <<-
2023 Jul 08
1
Getting an error calling MASS::boxcox in a function
Thanks John.
?boxcox says:
*************************
Arguments
object
a formula or fitted model object. Currently only lm and aov objects are handled.
*************************
I read that as saying that
boxcox(lm(z+1 ~ 1),...)
should run without error. But it didn't. And perhaps here's why:
BoxCoxLambda <- function(z){
b <- MASS:::boxcox.lm(lm(z+1 ~ 1), lambda = seq(-5, 5,
2023 Jul 08
1
Getting an error calling MASS::boxcox in a function
Hi Bert,
On 2023-07-08 3:42 p.m., Bert Gunter wrote:
> Caution: This email may have originated from outside the organization. Please exercise additional caution with any links and attachments.
>
>
> Thanks John.
>
> ?boxcox says:
>
> *************************
> Arguments
>
> object
>
> a formula or fitted model object. Currently only lm and aov objects