Displaying 20 results from an estimated 60000 matches similar to: "VGAM weights"
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
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)
2006 Oct 27
0
VGAM package released on CRAN
Dear useRs,
upon request, the VGAM package (currently version 0.7-1) has been
officially released on CRAN (the package has been at my website
http://www.stat.auckland.ac.nz/~yee/VGAM for a number of years now).
VGAM implements a general framework for several classes of
regression models using iteratively reweighted least squares
(IRLS). The key ideas are Fisher scoring, generalized linear
and
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
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))
2007 May 31
0
VGAM package
Hi, R-users
Could someone help me to understand this following error. I'm using vglm
function in VGAM package
Best regards and thank you for your ehlp
########
mydata <- read.table("Data2_overruns.csv", sep =";", header = T,
row.names=NULL)
> attach(mydata)
>
> y <- mydata$cat.event
> phase.vol <-mydata$phase.vol
> pilote <- mydata$pilote
2008 Nov 14
0
VGAM package released on CRAN
Dear Prof. Thomas Yee
I$B!G(Bm very interested in your R program VGAM.
I tried below your data:
# Nonparametric proportional odds model
data(pneumo)pneumo = transform(pneumo,
let=log(exposure.time))vgam(cbind(normal,mild,severe) ~ s(let),
cumulative(par=TRUE), pneumo)
However, the results by Version of VGAM are different;
----------The result by Version 0.7-7
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
$vfamily).
I thought namespaces should protect us from this happening?
Kjetil
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2011 Jun 22
2
VGAM constraints-related puzzle
Hello R users,
I have a puzzle with the VGAM package, on my first excursion into
generalized additive models, in that this very nice package seems to
want to do either more or less than what I want.
Precisely, I have a 4-component outcome, y, and am fitting multinomial
logistic regression with one predictor x. What I would like to find
out is, is there a single nonlinear function f(x) which acts
2011 Aug 23
1
P values for vglm(zibinomial) function in VGAM
Hi ,
I know this question has been asked twice in the past but to my knowldege,
it still hasn't been solved.
I am doing a zero inflated binomial model using the VGAM package, I need to
obtain p values for my Tvalues in the vglm output. code is as follows
> mod2=vglm(dmat~Season+Diel+Tidal.phase+Tidal.cycle,zibinomial, data=mp1)
> summary(mod2)
Call:
vglm(formula = dmat ~ Season +
2007 Jan 06
2
Using VGAM's vglm function for ordinal logistic regression
R-Experts:
I am using the vglm function of the VGAM library to perform proportional
odds ordinal logistic regression. The issue that I would like help with
concerns the format in which the response variable must be provided for
this function to work correctly. Consider the following example:
------
library(VGAM)
library(MASS)
attach(pneumo)
pneumo # Inspect the format of the original dataset
2010 Jul 05
1
question concerning VGAM
Hello everyone,
using the VGAM package and the following code
library(VGAM)
bp1 <- vglm(cbind(daten$anzahl_b, daten$deckung_b) ~ ., binom2.rho,
data=daten1)
summary(bp1)
coef(bp1, matrix=TRUE)
produced this error message:
error in object$coefficients : $ operator not defined for this S4 class
I am bit confused because some day ago this error message did not show up
and
2008 Feb 08
0
Cumulative multinomial regression using VGAM
Hi,
I am trying to carry out a multinomial regression using the cumlogit link function. I have tried using the VGAM package, and have gotten some results...
fit1 <- vgam(Y ~ X1 + X2 + X3 + X4,
cumulative(link=logit,intercept.apply=FALSE,parallel=TRUE),
data = data1
)
The problem arrises when I try to get the information out of the fitted object. I can
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
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) /
2009 Jun 05
2
p-values from VGAM function vglm
Anyone know how to get p-values for the t-values from the coefficients
produced in vglm?
Attached is the code and output ? see comment added to output to show
where I need p-values
+ print(paste("********** Using VGAM function gamma2 **********"))
+ modl2<-
vglm(MidPoint~Count,gamma2,data=modl.subset,trace=TRUE,crit="c")
+ print(coef(modl2,matrix=TRUE))
2005 Apr 10
2
residuals in VGAM
Hi all:
I want to fit a multinomial logit model with VGAM package, however I cannot find a way to check the residuals since
residuals(my_model) and resid(my_model)
does not work.
Any suggestions?
Thanks in advance.
Alex Brito
[[alternative HTML version deleted]]
2009 Mar 26
0
VGAM and cnstraints
Dear R-Users,
I am learning how to use the package VGAM to do multinomial regressions.
I have worked through the example provided by UCLA stats group:
http://www.ats.ucla.edu/stat/r/dae/mlogit.htm
However - what I would like to learn is how to use the constraint option.
So in the example given in the link i would like to introduce a constraint that
does not allow individuals of age less than
2009 Jan 29
0
Problem VGAM and Predict
Hello,
since I installed the package VGAM I have problems useing the predict for othere methods.
for example I have a model from glm and polr the command predict(model) I get the error: unable to find an inherited method for function "predict", for signature "polr".
Has perhaps anybody a solution, because Iwould need vglm and also other methods like tree in a loop.
Thanks a
2007 Jun 13
1
VGAM Pareto
I would like to fit a Pareto Distribution and I am using the following codes
fit=vglm(ycf1 ~ 1, pareto1(location=alpha), trace=TRUE, crit="c")
fitted(fit)
But the fitted values turn out to be the same for each observation. I guess
the problem is with "ycf1 ~ 1",
I would be grateful if anyone can give me some advice on how to define the
formula.
Many thanks
--
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