Displaying 20 results from an estimated 300 matches similar to: "weighted Cox proportional hazards regression"
2011 Feb 27
3
nested case-control study
Hi, I am wondering if there is a package for doing conditional logistic
regression for nested case-control study as described in "Estimation of absolute
risk from nested case-control data" by Langholz and Borgan (1997) where
Horvitz-Thompson sampling weight (log of (number in the risk set divided by the
number sampled)) is used with regression. In SAS Proc Phreg, this is implemented
2011 Apr 30
1
help with a survplot
Dear useRs,
I was asked to produce a survival curve like this:
http://www.palug.net/Members/jabba/immaginetta.png/view
with the cardinality of the riskset at the bottom.
I do not like doing it, because it doesn't add any valuable information
and because it doesn't discriminate between died and censored.
Nevertheless, is there someone able to tell me how to do it? Currently
the only
2009 Aug 20
1
Understanding R code
What is
1. par.ests <- optimfit$par
2. fisher <- hessb(negloglik, par.ests, maxvalue=maxima);
3. varcov <- solve(fisher);
4. par.ses <- sqrt(diag(varcov));
Thanks a lot,
fit.GEV <- function(maxima)
{
sigma0 <- sqrt((6. * var(maxima))/pi)
mu0 <- mean(maxima) - 0.57722 * sigma0
xi0 <- 0.1
theta <- c(xi0, mu0, sigma0)
#10/5/2007: removed assign() for maxima.nl
2009 Jul 02
1
Quantitative Risk Management by McNeil
Dear Specialists in R,
May be somebody has experiment in using pakage for the book Quantitative
Risk Management by McNeil?
This package is writen in R.
I have run this package for fitting the data to Nornal Inverse Gaussian
distribution and fased with following problem.
> Return<-read.csv("data.csv")
> Transpose<-t(Return)
> fit.NH(Transpose, case="NIG",
2008 May 23
1
maximizing the gamma likelihood
for learning purposes and also to help someone, i used roger peng's
document to get the mle's of the gamma where the gamma is defined as
f(y_i) = (1/gammafunction(shape)) * (scale^shape) * (y_i^(shape-1)) *
exp(-scale*y_i)
( i'm defining the scale as lambda rather than 1/lambda. various books
define it differently ).
i found the likelihood to be n*shape*log(scale) +
2013 Oct 04
2
Survival
Hola.
Una duda....
Alguien sabe si hay algo hecho en R para comprobar si un modelo de supervivencia está bien calibrado?
(usando las pruebas de Nam-D'Agostino o de Gronnesby & Borgan).
Thnks.
Un Saludo,
_____________________________
Miguel Ángel Rodríguez Muíños
Dirección Xeral de Innovación e Xestión da Saúde Pública
Consellería de Sanidade
Xunta de Galicia
http://dxsp.sergas.es
2006 Sep 14
0
Help On EBAM
Dear RUsers,
I am new to R. I am learning how to use R. I am a PC user and run R on
windows. I would appreciate if some one could guide me on a few questions I
have:
1) I have 4 cel files (2 replicates for NORM and Disease resp). I have been
able to run siggenes on this dataset where I have 4 labels in the class file
groupsnhi.cl op-> (0,0,1,1) and my data has been read into datrmanhi after
2006 Sep 14
1
EBAM ERROR
Dear RUsers,
I am new to R. I am learning how to use R. I am a PC user and run R on
windows. I would appreciate if some one could guide me on a few questions I
have:
1) I have 4 cel files (2 replicates for NORM and Disease resp). I have been
able to run siggenes on this dataset where I have 4 labels in the class file
groupsnhi.cl op-> (0,0,1,1) and my data has been read into datrmanhi after
2004 Aug 15
2
analysis of life tables
Dear all,
How can I analyze a life table (e.g. for a cohort of insects) in R?
I have 20 insects in 200 cages with two different treatments, whose
survival is followed over time, such that, e.g., in one treatment, the
number of animals surviving is c(20,18,16,12,10,8,4,0), while in the
other treatment the survival is c(20,20,18,18,16,15,15,14) at 8
subsequent time intervals.
I would very
2019 Sep 12
0
Fw: Calling a LAPACK subroutine from R
Hi guys,
interestingly, my problem seems to be solved by writing a FORTRAN
wrapper for the Fortran code! (As long as the check doesn't get
smarter...). This is the relevant part of my Fortran code:
-----------------------------------------------------------
subroutine gmlfun(what,
& totevent, totrs, ns,
& antrs, antevents, size,
& totsize,
2012 Oct 16
2
R Kaplan-Meier plotting quirks?
Hello. I apologize in advance for the VERY lengthy e-mail. I endeavor to
include enough detail.
I have a question about survival curves I have been battling off and on for
a few months. No one local seems to be able to help, so I turn here. The
issue seems to either be how R calculates Kaplan-Meier Plots, or something
with the underlying statistic itself that I am misunderstanding. Basically,
2013 Oct 04
3
Survival
Hola Carlos.
Muchas gracias.
No es exactamente lo que estoy buscando (sería genial ver que alguien tiene un paquete con la prueba de Nam-D'Agostino) pero puedo aprovechar algo de código.
Encontré alguna referencia al test de Gronnesby&Borgan en el paquete stcoxgof de Stata, pero estoy torpe para encontrar algo hecho en R (y me extraña que no haya nada)
Un saludo,
Miguel.
De: Carlos
2004 Aug 10
1
Question about mle function
Dear all,
I'd like to find the mle esttimates using the mle function
mle(negloglik, start = list(), fixed=list(), method="...").
I am using the L-BGFS-B method and I don't supply the gradient function. Is there a way to print the gradients found at the solution value?
I am using R-1.9.1 on Windows and on Unix.
Thank you in advance,
Victoria Landsman.
[[alternative
2004 Oct 05
1
Bug in optim - way to solve problem?
Hi,
I want to automatically fit variograms to a large number of different
sample data sets, and call the funtion "likfit" (in package geoR) from
within a for-loop. "likfit" does again call "optim". After ssuccessfully
fitting variograms to some of the data sets, the procedure crashes and I
get the error message:
Error in optim(par = ini, fn = negloglik.GRF,
2015 Apr 06
3
[LLVMdev] uCLibc support for klee
Hello,
In my reading over the last couple of days, I have read that in order
for klee to work with "native" Linux programs, I need to install the
uClibc posix support for klee.
I am not finding the uClibc source in the llvm svn repository anywhere.
Is this still necessary for testing native Linux applications, and if
so, where do I get the uClibc source to compile?
Thanks in
2019 Sep 11
4
Fw: Calling a LAPACK subroutine from R
Sorry for cross-posting, but I realized my question might be more appropriate for r-devel...
Thank you,
Giovanni
________________________________________
From: R-help <r-help-bounces at r-project.org> on behalf of Giovanni Petris <gpetris at uark.edu>
Sent: Tuesday, September 10, 2019 16:44
To: r-help at r-project.org
Subject: [R] Calling a LAPACK subroutine from R
Hello R-helpers!
2004 Apr 22
1
slower execution in R 1.9.0
I have an R function (about 1000 lines long) that takes more than 20
times as long to run under R Windows 1.9.0 and 1.8.1 than it does under
1.7.1. Profile results indicate that the $<-.data.frame operation is
the culprit, but I don't understand exactly what that is (assignment of
data frame elements to another variable?), or why it's only a problem
under 1.8.1 and 1.9.0. Any advice?
2004 Sep 19
1
NAMESPACE Warning
I'm trying to learn how to use namespaces, so I have created a small
package with two functions. My NAMESPACE file is
importFrom(survival, Surv)
export(mlreg.fit, risksets)
because 'mlreg.fit' uses 'Surv' from 'survival'. However I get
* checking package dependencies ... WARNING
Namespace dependencies not required:
survival
Why? (If I remove 'importFrom' I
2004 Sep 19
1
Namespace problem
Now I try to add some C and Fortan code to my package, so the NAMESPACE
file is
useDynLib(eha)
importFrom(survival, Surv)
export(mlreg.fit, risksets)
but I get
.....
* checking R files for library.dynam ... OK
* checking S3 generic/method consistency ... WARNING
Error in .try_quietly({ : Error in library(package, lib.loc = lib.loc, character.only = TRUE, verbose = FALSE) :
2004 Aug 13
1
How to use the whole dataset (including between events) in Cox model (time-varying covariates) ?
Hello,
coxph does not use any information that are in the dataset between event
times (or "death times") , since computation only occurs at event times.
For instance, removing observations when there is no event at that time in
the whole dataset does not change the results:
> set.seed(1)
> data <-
as.data.frame(cbind(start=c(1:5,1:5,1:4),stop=c(2:6,2:6,2:5),status=c(rep(