Displaying 20 results from an estimated 110 matches similar to: "Problems and bugs in vgam()"
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.
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.
2011 Sep 02
2
How to keep the same class?
Hello
Please see the example below
> class(testX)
[1] "matrix"
> class(testX[1,])
[1] "numeric"
Why not matrix? What am I missing here? Is there a way to keep the same
class?
The reason for the question is that I want to implement a k-step ahead
prediction for my own routines and R wrecks does not seem to like [1,] as
shown below.
>
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
2010 Sep 10
1
lme, groupedData, random intercept and slope
Windows Vista
R 2.10.1
Does the following use of groupedData and lme produce an analysis with both random intercept and slope, or only random slope?
zz<-groupedData(y~time | Subject,data=data.frame(data),
labels = list( x = "Time",
y = "y" ),
units = list( x = "(yr)", y = "(mm)")
)
plot(zz)
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
--
2012 Jun 05
1
Do YOU know an equation for splines (ns)?
Hi,
I am looking at the change in N concentration in plant roots over 4 time
points and I have fit a spline to the data using ns and lme:
fit10 <- lme( N~ns(day, 3), data = rcn10G)
I may want to adjust the model a little bit, but for now, let's assume it's
good. I get output for the fixed effects:
Fixed: N ~ ns(day, 3)
(Intercept) ns(day, 3)1 ns(day, 3)2 ns(day, 3)3
2012 May 31
0
splines and ns equation
Hi,
I am looking at the change in N concentration in plant roots over 4 time
points and I have fit a spline to the data using ns and lme:
fit10 <- lme( N~ns(day, 3), data = rcn10G)
I may want to adjust the model a little bit, but for now, let's assume it's
good. I get output for the fixed effects:
Fixed: N ~ ns(day, 3)
(Intercept) ns(day, 3)1 ns(day, 3)2 ns(day, 3)3
1.15676524
2004 Jul 12
6
proportions confidence intervals
Dear R users
this may be a simple question - but i would appreciate any thoughts
does anyone know how you would get one lower and one upper confidence
interval for a set of data that consists of proportions. i.e. taking a
usual confidence interval for normal data would result in the lower
confidence interval being negative - which is not possible given the data
(which is constrained between
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
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
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 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
2005 Jun 06
0
VGAM weights
sorry...its the same post but this time with subject
dear all:
I want try the vgam function in VGAM library, but I'm stucked since I
can't define the weights. This is because I dont understand well the
concept of "matrix-band" (even after read the reference card).
I was wondering if someone have some tutorial examples of how to define
weights on a matrix form, in VGAM.
thank
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
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]]
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) /
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
--
View this
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
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)