Displaying 20 results from an estimated 700 matches similar to: "Bug in VGAM z value and coefficient ?"
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
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))
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.
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
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
2007 Nov 16
1
constraint matrices in vglm (VGAM package)
Hello R users,
I am performing a multinomial logit regression and would like to
constrain a few model coefficients to be equal.
Here is my model:
multi <- vglm(case123con ~ SNP_A1+SNP_A2+age, multinomial, work.analy)
where case123con is a four level categorical variable (case 1, case 2,
case 3, control) and SNP_A1 and SNP_A2 are indicator functions (yes/no).
The output of this
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
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
2009 Nov 04
1
vglm(), t values and p values
Hi All,
I'm fitting an proportional odds model using vglm() from VGAM.
My response variable is the severity of diseases, going from 0 to 5 (the
severity is actually an ordered factor).
The independent variables are: 1 genetic marker, time of medical observation,
age, sex. What I *need* is a p-value for the genetic marker. Because I have ~1.5
million markers I'd rather not faffing
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 +
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 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
2009 Jun 26
1
predicted values after fitting gamma2 function
Question: after fitting a gamma function to some data, how do I get
predicted values? I'm a SAS programmer, I new R, and am having
problems getting my brain to function with the concept of "object as
class ...". The following is specifics of what I am doing:
I'm trying to determine the pdf from data I have created in a
simulation.
I have generated frequency counts
2012 Oct 23
1
Testing proportional odds assumption in R
I want to test whether the proportional odds assumption for an ordered
regression is met.
The UCLA website points out that there is no mathematical way to test the
proportional odds assumption (http://www.ats.ucla.edu/stat//R/dae/ologit.htm),
and use graphical inspection ("We were unable to locate a facility in R to
perform any of the tests commonly used to test the parallel slopes
2005 Jun 02
1
how to rectify t.test( ) error
Hi All,
I get the following error when i perform a t.test.
studentt<-apply(tlr, 1, function(x) t.test(x[2:6], x[7:11],var.equal=TRUE)$p.value)
# tlr is a table of 11 columns and 22500 rows. I am not able to post tlr due to its size.
Error in if (stderr < 10 * .Machine$double.eps * max(abs(mx), abs(my))) stop("data are essentially constant") :
missing value where
2011 Jan 21
1
Maxiter specification in R
Dear R users,
I'm having a problem with maxiter specification in VGLM function. I tried to
increase the number of iteration to 100, but it still stopped at 30, which
is the default. Here is my script:
FIT <- vglm(SFH_PCT ~ RD_DEN + CAR_HH + TRS + RES_L, tobit(Lower=0), maxiter
= 100)
Thanks
Gary
[[alternative HTML version deleted]]
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
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)
2010 Aug 31
4
vglm
Hi All,
could anybody help me to understand what is this error means ?
mydata=read.table("C:/Documents and
Settings/angieb/Desktop/CommercialGL/cl_ilf_claimdata.csv",header=TRUE,sep=",")
> names(mydata)
[1] "ILFTable" "liabLimit" "AnnAggLimit" "DedAmt" "Loss"
"TIL"
>