Displaying 20 results from an estimated 900 matches similar to: "using loglog link in VGAM or creating loglog link for GLM"
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
2008 Dec 27
1
Zipf fitting using R
Dear R-users,
I am new to R and would like to use it for fitting the zipf distribution to
some numeric data that I have. Here's the snippet that I use:
library(VGAM)
X <- read.table(file("~\\mydata.txt", encoding="latin1"))
w <- as.vector(t((X[2])))
w <- w/sum(w)
y <- (1:length(w))
fit = vglm (y ~ 1, zipf, tra=TRUE, weight=w)
zipf(N=NULL,
2005 Feb 07
2
logit link + alternatives
Help needed with lm function:
Dear R's,
Could anyone tell me how to replace the link function (probit logit,
loglog etc.) in lm
with an abitrary user-defined function? The task is to perform ML
Estimation of betas
for a dichotome target variable.
Maybe there is already a package for this (I did not find one).
Any hints or a code excerpt would be welcome!
Thank you -Jeff
jeff.pr2 (at)
2001 Apr 30
1
Some loglog density plot
Dear all,
A looong time ago, Witold Eryk Wolski asked here why there wasn't a
log="xy" parameter to the hist() function
<URL:http://www.R-project.org/nocvs/mail/r-help/2001/0267.html>, and
Prof. Ripley responded that a loglog histogram does not make much sense,
and that one should use a better density estimate if one seeks to plot
log density.
I understand the point and I
2007 Oct 29
1
VGAM and vglm
Hi Folks,
I wonderif someone who is familiar with the details
of vglm in the VGAM package can assist me. I'm new
to using it, and there doesn;t seem much in the
documentation that's relevant to the question below.
Say I have a vector x of 0/1 responses and another
vector y of 0/1 responses, these in fact being a
bivariate set of 0/1 responses equivalent to
cbind(x,y).
E.g.
2005 May 28
3
Incompatibility with VGAM
I just discovered that when the VGAM package (not on CRAN) is loaded,
glm() doesn't work. This is because VGAM defines a family function()
which gets found
by glm() in place of the family function from stats.
Then VGAM:::family returns an object which doesn't have a $family
component, (it has a component
$vfamily).
I thought namespaces should protect us from this happening?
Kjetil
--
2009 Mar 26
0
(Interpretation) VGAM - FRECHET 3 parameters by maximum likelihood estimation for
Dear R Helpers
This is the R code (which I have slightly changed) I got in VGAM package for estimating the parameters of FRECHET.
_________________________________________________________________
y = rfrechet(n <- 100, shape=exp(exp(0))) # (A)
fit3 = vglm(y ~ 1, frechet3(ilocation=0), trace=TRUE, maxit=155) # (B)
coef(fit3, matrix=TRUE) # (C)
2013 Sep 13
1
log-log link function
Hi to every body. I would like assistance on how to implement the log-log
link function for binary response. Is there any package that implements it?
Many thanks
Endy
[[alternative HTML version deleted]]
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:
>
2008 Jun 13
1
Writing a new link for a GLM.
Hi,
I wish to write a new link function for a GLM. R's glm routine does
not supply the "loglog" link. I modified the make.link function adding
the code:
}, loglog = {
linkfun <- function(mu) -log(-log(mu))
linkinv <- function(eta) exp(-exp(-eta))
mu.eta <- function(eta) exp(-exp(-eta)-eta)
valideta <- function(eta) all(eta != 0)
2008 Oct 10
0
Problems and bugs in vgam()
Hello R-Users,
I have recently run into several problems using vgam() in the VGAM
package. I am hoping someone might have some solutions...
Briefly, I have been trying to fit GAM models for zero-altered negative
binomial models.
1. When fitting smoothed parameters (e.g. s(X, df=2)) changing the
degrees-of-freedom has no effect on the level of smoothing (e.g. number
of knots for the
2012 Jan 10
1
S4 summary method not being called (VGAM)
The symptom triggering this email is that an S4 summary method sometimes refuses to be invoked, even when a package is explicitly loaded, if the first load of the package is implicit. It may or may not be specific to 'summary' methods and/or the 'VGAM' package. I've sent to R-devel because (i) it looks like some kind of bug to me, but I'm not sure; (ii) it's not
2004 May 29
1
GLMM error in ..1?
I'm trying to use GLMM in library(lme4), R 1.9.0pat, updated just
now. I get an error message I can't decipher:
library(lme4)
set.seed(1)
n <- 10
N <- 1000
DF <- data.frame(yield=rbinom(n, N, .99)/N, nest=1:n)
fit <- GLMM(yield~1, random=~1|nest, family=binomial, data=DF,
weights=rep(N, n))
Error in eval(expr, envir, enclos) : ..1 used in an incorrect
2006 Oct 05
2
VGAM Package ?
Hi! R users
I would like to ask you where could we find the VGAM Package. I don't find
it in the list of packages.
Thak you for your help
Lassana KOITA
Etudes de S?curit? et d'Exploitation a?roportuaires / Safety Study &
Statistical analysis
Service Technique de l'Aviation Civile (STAC) / Civil Aviation Technical
Department
Direction G?n?rale de l'Aviation Civile (DGAC) /
2008 Sep 09
1
Genmod in SAS vs. glm in R
Hello,
I have different results from these two softwares for a simple binomial GLM
problem.
>From Genmod in SAS: LogLikelihood=-4.75, coeff(intercept)=-3.59,
coeff(x)=0.95
>From glm in R: LogLikelihood=-0.94, coeff(intercept)=-3.99, coeff(x)=1.36
Is there anyone tell me what I did wrong?
Here are the code and results,
1) SAS Genmod:
% r: # of failure
% k: size of a risk set
data
2013 Apr 17
1
Bug in VGAM z value and coefficient ?
Dear,
When i multiply the y of a regression by 10, I would expect that the
coefficient would be multiply by 10 and the z value to stay constant. Here
some reproducible code to support the case.
*Ex 1*
library(mvtnorm)
library(VGAM)
set.seed(1)
x=rmvnorm(1000,sigma=matrix(c(1,0.75,0.75,1),2,2))
2008 Apr 18
2
rzinb (VGAM) and dnbinom in optim
Dear R-help gurus (and T.Yee, the VGAM maintainer) -
I've been banging my head against the keyboard for too long now, hopefully someone can pick up on the errors of my ways...
I am trying to use optim to fit a zero-inflated negative binomial distribution. No matter what I try I can't get optim to recognize my initial parameters. I think the problem is that dnbinom allows either
2013 Nov 20
1
Binomial GLM in Stata and R
Hello,
I'm not a Stata user so I'm trying to reproduce Stata results that are given to me in R. I would like to use a GLM with a complementary log-log function. The stata code I have is:
glm c IndA fia, family(binomial s) link(cloglog) offset(offset)
The R code is:
glmt <- glm(data=dataset, c ~ IndA + fia, offset = offset, family = binomial(link = cloglog))
Which yields
2011 Jun 22
2
VGAM constraints-related puzzle
Hello R users,
I have a puzzle with the VGAM package, on my first excursion into
generalized additive models, in that this very nice package seems to
want to do either more or less than what I want.
Precisely, I have a 4-component outcome, y, and am fitting multinomial
logistic regression with one predictor x. What I would like to find
out is, is there a single nonlinear function f(x) which acts
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