Displaying 20 results from an estimated 1000 matches similar to: "Confusing difference in S4 summary method dispatch within an S3 summary"
2007 Nov 01
1
Zelig and the "blogit" model
Hi Folks,
According to the PDF file blogit.pdf in the Zelig
documentation:
"Use the bivariate logistic regression model ["blogit"]
if you have two binary dependent variables (Y1,Y2), and
and wish to model them jointly as a function of some
explanatory variables. Each pair of dependent variables
(Yi1,Yi2) has four potential outcomes, (Yi1=1,Yi2=1),
(Yi1=1,Yi2=0),
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))
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))
2009 Jun 16
0
Generation from COX PH with gamma frailty
Hello,
I want to generate data set from Cox PH model with gamma frailty effects.
theta(parameter for frailty distribution)=2
beta=1.5
n=300
cluster size=30
number of clusters=10
I think I should first generate u from Gamma(Theta,theta) and then using
this theta I could not decide how I should generate the survival times?
Is there any package for this? or any document you could suggest?
Any
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.
2008 Jan 07
0
R vglm new family writing: mix Poisson/multinomial
Hi dear R users,
1)
I would like to know if there is a simple way to define a vglm family which
would be a mix of poisson variables and bernoulli variables (0/1 response)
for idea this would be invoked like this:
vglm(...,family=mixpoissonmultinom(npoisson,n01response))
where the n's give the number of each type of response.
2)
and a simpler question : How to use constraints in rrvglm?
2012 Oct 26
1
Is there any way of weighting individual data points in a logistic regression
Dear all. Apologies if I am asking a stupid question, but I have been unable to find a solution so far.
I would like to run a logistic regression in which individual data points are assigned different weights (related to my confidence in their validity). These individual observations are binary (success/failure). My intuition was to use the "weights" option in the vlm function.
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
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
2004 Mar 23
0
New R package
Zelig: Everyone's Statistical Software
Kosuke Imai, Gary King and Olivia Lau
Version 1.0
(Available at http://gking.harvard.edu/zelig)
A growing proportion of statisticians and methodologists from many
disciplines are converging on R, a powerful statistics package and
programming language. As an open source project, R is freely
2012 Apr 04
0
multivariate ordered probit regression---use standard bivariate normal distribution?
Hello.
I have yet to receive a response to my previous post, so I may have
done a poor job asking the question. So, here is the general question:
how can I run a run a multivariate (more than one non-independent,
response variables) ordered probit regression model? I've had success
doing this in the univariate case using the vglm() function in the
VGAM package. For example:
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
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 +
2010 Dec 21
0
"variable lengths differ (found for '(weights)')" error in Zelig library
Dear R users,
I am trying to estimate to estimate the average treatmen effect on the
treated (ATT) using first the MatchIt software to weight the data set and,
after this, the Zelig software as shown in Ho et al. (2007). See here for an
explanation of how to apply this technique in R:
http://imai.princeton.edu/research/files/matchit.pdf
I encounter a slight problem when I apply the weights that
2009 Feb 19
0
Zelig method setx()
Hello,
I am attempting to "automate" a Bayesian normal linear regression
using Zelig. Basically, I have a list containing several zelig()
objects, each having a different formula, same data set, and same
model (normal.bayes).
My problem lies in the setx() method, where I am setting a numeric
parameter to a value other than the mean. This is straightforward if
I input the parameters
2011 Dec 16
0
Error constructing probabilities in Zelig
I've run an ordered logistic regression model in R with Zelig and am
looking to calculate predicted probabilities. Zelig has a series of simple
one line commands to generate the information I want on first differences
and so forth. Unfortunately, I keep getting an error when running the zelig
function and was wondering if there was a quick alternative for generating
predicted probabilities for
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 Mar 05
2
Zelig package: Coxph model problems
Hi,
I'm having problems with the Zelig package - when using
the below R displays the follwing message (I'm running R
i386 2.15.3 for Windows and have updated all the Zelig
packages):
z.out<-zelig(Surv(psurv2, pcens2) ~ ren_sup3 + age,
data=data_urgent, model="coxph")
** The model "coxph" is not available with the currently
loaded packages,
** and is not an
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 Mar 21
0
multivariate ordinal probit regression vglm()
Hello, all.
I'm investigating the rate at which skeletal joint surfaces pass
through a series of ordered stages (changes in morphology). Current
statistical methods in this type of research use various logit or
probit regression techniques (e.g., proportional odds logit/probit,
forward/backward continuation ratio, or restricted/unrestricted
cumulative probit). Data typically include the