Displaying 20 results from an estimated 10000 matches similar to: "interval-censored data in coxph"
2006 Feb 13
2
Survreg(), Surv() and interval-censored data
Can survreg() handle interval-censored data like the documentation
says? I ask because the command:
survreg(Surv(start, stop, event) ~ 1, data = heart)
fails with the error message
Invalid survival type
yet the documentation for Surv() states:
"Presently, the only methods allowing interval censored data are
the parametric models computed by 'survreg'"
2007 Nov 29
1
Survreg(), Surv() and interval-censored data
Can anybody give me a neat example of interval censored data analysis codes in R?
Given that suvreg(Surv(c(1,1,NA,3),c(2,NA,2,3),type="interval2")~1)
works why does
survreg(Surv(data[,1],data[,2],type="interval2")~1)
not work where
data is :
T.1 T.2 Status
1 0.0000000 0.62873036 1
2 0.0000000 2.07039068 1
3 0.0000000
2008 Dec 23
6
Interval censored Data in survreg() with zero values!
Hello,
I have interval censored data, censored between (0, 100). I used the
tobit function in the AER package which in turn backs on survreg.
Actually I'm struggling with the distribution. Data is asymmetrically
distributed, so first choice would be a Weibull distribution.
Unfortunately the Weibull doesn't allow for zero values in time data,
as it requires x > 0. So I tried the
2006 May 03
3
Giving Error
I tried your code, but it's giving the following
error..
Error in match.fun(FUN) : argument "FUN" is missing,
with no default
2009 Jan 09
2
rpart with interval censored data crashes R
Hi Everyone,
This example code results in R 'crashing'; that is the R application closes
with no warnings or error messages.
#-----------------------
myD <- read.table(stdin(), header=TRUE, nrows=20)
Broth Salt pH Temp N Y Growth
1 310 9.0 2.92 10 90.0 NA 0
2 615 6.0 7.82 30 1.0 2 1
3 217 2.0 7.34 10 7.0 8
2008 Mar 13
1
How to set type of censored data in coxph regression
Dear R users,
I tried to analysis the hazard function of some data by coxph function
in survival package.
The type of the data include "left-censored", "right-censored", "both
right-censored and
left-censored" (btw, does this has a technical term?), and "complete" ones.
I noticed that event (one parameter in "Surv()") might be an indicator
for the
2007 Apr 23
3
fitting mixed models to censored data?
Hi,
I'm trying to figure out if there are any packages allowing
one to fit mixed models (or non-linear mixed models) to data
that includes censoring.
I've done some searching already on CRAN and through the mailing
list archives, but haven't discovered anything. Since I may well
have done a poor job searching I thought I'd ask here prior to
giving up.
I understand that
2012 May 11
2
survival analysis simulation question
Hi,
I am trying to simulate a regression on survival data under a few
conditions:
1. Under different error distributions
2. Have the error term be dependent on the covariates
But I'm not sure how to specify either conditions. I am using the Design
package to perform the survival analysis using the survreg, bj, coxph
functions. Any help is greatly appreciated.
This is what I have so far:
2003 Feb 27
2
interval-censored data in survreg()
I am trying to fit a lognormal distribution on interval-censored
data. Some of my intervals have a lower bound of zero.
Unfortunately, it seems like survreg() cannot deal with lower
bounds of zero, despite the fact that plnorm(0)==0 and
pnorm(-Inf)==0 are well defined. Below is a short example to
reproduce the problem.
Does anyone know why survreg() must behave that way?
Is there an alternate
2010 Nov 12
3
predict.coxph
Since I read the list in digest form (and was out ill yesterday) I'm
late to the discussion.
There are 3 steps for predicting survival, using a Cox model:
1. Fit the data
fit <- coxph(Surv(time, status) ~ age + ph.ecog, data=lung)
The biggest question to answer here is what covariates you wish to base
the prediction on. There is the usual tradeoff between too few (leave
out something
2004 May 16
2
Error in using coxph()
Hi,
I am getting errors of the following kind. I can't
seem to point the source of the error. I would greatly
appreciate any advice.
Many thanks and good day,
-Melinda
Error message :
----------------
"Ran out of iterations and did not converge in:
fitter(X, Y, strats, offset, init, control, weights =
weights,..."
Details :
---------
E is a vector of survival times (or censored
2005 Nov 23
1
survdiff for Left-truncated and right-censored data
dear all,
I would like to know whether survdiff and survReg function in the
survival package work for left-truncated and right-censored data.
If not, what other functions can i use to make comparison between two
survival curves with LTRC data.
thanks for any help given
sing yee
2011 Aug 26
2
How to generate a random variate that is correlated with a given right-censored random variate?
Hi,
I have a right-censored (positive) random variable (e.g. failure times subject to right censoring) that is observed for N subjects: Y_i, I = 1, 2, ..., N. Note that Y_i = min(T_i, C_i), where T_i is the true failure time and C_i is the censored time. Let us assume that C_i is independent of T_i. Now, I would like to generate another random variable U_i, I = 1, 2, ..., N, which is
2010 Jun 23
1
Probabilities from survfit.coxph:
Hello:
In the example below (or for a censored data) using survfit.coxph, can
anyone point me to a link or a pdf as to how the probabilities appearing in
bold under "summary(pred$surv)" are calculated? Do these represent
acumulative probability distribution in time (not including censored time)?
Thanks very much,
parmee
*fit <- coxph(Surv(futime, fustat) ~ age, data = ovarian)*
2005 Sep 07
1
Survival analysis with COXPH
Dear all,
I would have some questions on the coxph function for survival analysis,
which I use with frailty terms.
My model is:
mdcox<-coxph(Surv(time,censor)~ gender + age + frailty(area, dist='gauss'),
data)
I have a very large proportion of censored observations.
- If I understand correctly, the function mdcox$frail will return the random
effect estimated for each group on the
2011 Dec 19
1
Calculating the probability of an event at time "t" from a Cox model fit
Dear R-users,
I would like to determine the probability of event at specific time using
cox model fit. On the development sample data I am able to get the
probability of a event at time point(t).
I need probability score of a event at specific time, using scoring scoring
dataset which will have only covariates and not the response variables.
Here is the sample code:
n = 1000
beta1 = 2; beta2 =
2008 Jan 22
2
MLE for censored distributions in R
Hi just wondering if there is a package that can get the maximum likelihood
or method of moments estimator for distributions with censored data? The
distributions I'm interested in are: Exponential, pareto, beta, gamma and
lognormal.
--
View this message in context: http://www.nabble.com/MLE-for-censored-distributions-in-R-tp15022863p15022863.html
Sent from the R help mailing list archive at
2010 Nov 11
2
predict.coxph and predict.survreg
Dear all,
I'm struggling with predicting "expected time until death" for a coxph and
survreg model.
I have two datasets. Dataset 1 includes a certain number of people for which
I know a vector of covariates (age, gender, etc.) and their event times
(i.e., I know whether they have died and when if death occurred prior to the
end of the observation period). Dataset 2 includes another
2003 Apr 20
1
survreg penalized likelihood?
What objective function is maximized by survreg with the default
Weibull model? I'm getting finite parameters in a case that has the
likelihood maximzed at Infinite, so it can't be a simple maximum
likelihood.
Consider the following:
#############################
> set.seed(3)
> Stress <- rep(1:3, each=3)
> ch.life <- exp(9-3*Stress)
> simLife <- rexp(9,
2011 Dec 07
1
survreg() provides same results with different distirbutions for left censored data
Hello,
I'm working with some left censored survival data using accelerated failure
time models. I am interested in fitting different distributions to the data
but seem to be getting the same results from the model fit using survreg
regardless of the assumed distribution.
These two codes seem to provide the same results:
aft.gaussian <-