Displaying 20 results from an estimated 300 matches similar to: "multivariate ordered probit regression---use standard bivariate normal distribution?"
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
2010 Mar 06
1
Plotting Comparisons with Missing Data
Hi,
I'm new to R and I've run into a problem that I'm not really sure how to
express properly in the language. I've got a data table that I've read from
a file containing some simple information about the performance of 4
algorithms. The columns are the name of the algorithm, the problem instance
and the resulting score on that problem (if it wasn't solved I mark that
2010 Sep 06
1
calculating area between plot lines
Hi everyone. I have these data:
probClass<-seq(0,0.9,0.1)
prob1<-c(0.0070,0.0911,0.1973,0.2949,0.3936,0.5030,0.5985,0.6869,0.7820,0.8822)
prob2<-c(0.0066,0.0791,0.2358,0.3478,0.3714,0.3860,0.6667,0.6400,0.7000,1.0000)
# which I'm plotting as follows:
plot(probClass,prob1,xlim=c(0,1),ylim=c(0,1),xaxs='i',yaxs='i',type="n")
lines(probClass,prob1)
2009 Apr 21
4
My surprising experience in trying out REvolution's R
I care a lot about R's speed. So I decided to give REvolution's R
(http://revolution-computing.com/) a try, which bills itself as an
optimized R. Note that I used the free version.
My machine is a Intel core 2 duo under Windows XP professional. The code
I run is in the end of this post.
First, the regular R 1.9. It takes 2 minutes and 6 seconds, CPU usage
50%
Next, REvolution's R.
2002 Aug 06
3
hard to believe speed difference
First, I love R and am grateful to be using this free and extremely
high quality software.
Recently I have been comparing two algorithms and naturally I
programmed in R first. It is so slow that I can almost feel its pain.
So I decided to do a comparison with Java. To draw 500,0000 truncated
normal, Java program takes 2 second and R takes 72 seconds. Not a
computer science major, I find it hard
2007 Apr 11
1
package incompatibility under 2.5.0 (please respond directly, I am not on r-devel)
Dear all,
For my package "ref" I have implemented extensive regression testing. It now fails to compile since primitives "dim" and "dimnames" (and their assignment methods) no longer allow for additional arguments. I was using an additional argument "ref" with several methods. For "].refdata" it still works, with "dim.refdata" no longer.
2009 Dec 09
1
Warning for data.table (with ref)?
I have following the message "dim(refdata) and dimnames(refdata) no
longer allow parameter ref=TRUE, use dim(derefdata(refdata)),
dimnames(derefdata(refdata)) instead" when I loaded data.table. Is it
from the package ref? Could it be fixed? Or there is something wrong
with my installation?
> library(data.table)
Loading required package: ref
dim(refdata) and dimnames(refdata) no
2011 Nov 29
0
[SOLVED]looking for beta parameters
I managed to solve the problem myself without using this code.
thx
2011-11-24 12:26 keltezéssel, Kehl Dániel írta:
> Dear Community,
>
> I am trying to write code for the following problem.
> Lets assume we have a beta distribution.
> I know one quantile, lets say, 10% of the mass lies above .8, that is
> between .8 and 1.
> In addition, I know that the average of this
2011 Oct 06
1
sum of functions
Dear all,
I would like to create a code for semiparametric Klein and Spady's
estimator. For that I created a function that provides the log-likelihood
function for each observation (so it is a function of betas and i, where i
denotes the observation). Now, in order to maximize the log-likelihood
function, I have to sum these log-likelihood functions for each i and so to
get another function
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))
2008 Apr 22
2
Multidimensional contingency tables
How does one ideally handle and display multidimenstional contingency
tables in R v. 2.6.2?
E.g.:
> prob1<- data.frame(victim=c(rep('white',4),rep('black',4)),
+ perp=c(rep('white',2),rep('black',2),rep('white',2),rep('black',2)),
+ death=rep(c('yes','no'),4), count=c(19,132,11,52,0,9,6,97))
> prob1
victim perp
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.
2009 Jun 10
1
Analisys in Multidimensional contingency tables
Dear R-list,
Hi everyone, Im trying to make an analysis of multidimensional contingency
tables using R. I' working with the Agresti example where you have the
data from 3 categories. The thing is how can I do the analisys using the
G2 statistics. Somebody can send me an Idea?
I attach the program where you can find the data.
Best Regards,
> prob1<-
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?
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
2007 Jan 19
1
naive bayes help
Hello
I have a rather simple code and for some reason it produces an error
message. If someone can tell me why and how to fix it, I would be very
greatful. Thank you in advance.
##### create data
set.seed(10)
n <- 200 # number of training points
n.test <- 200 # number of test points
p<-2 # dimension of input space
z <-
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