Displaying 20 results from an estimated 9000 matches similar to: "R for reliability analysis (with censored samples)?"
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'"
2009 Feb 06
1
MLE for right-censored data with covariates
I am a student (and very to new to R) working on a senior design project that
is attempting to determine the demand distributions for single copy
newspaper draws at individual sales outlet locations. Our sales data is
right-censored, because sell-outs constitute a majority of the data, and we
are also testing the relevance of including covariates (weather,
seasonality, economic condition, etc.).
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
2008 Jan 23
2
Parametric survival models with left truncated, right censored data
Dear All,
I would like to fit some parametric survival models using left
truncated, right censored data in R. However I am having problems
finding a function to fit parametric survival models which can handle
left truncated data.
I have tested both the survreg function in package survival:
fit1 <- survreg(Surv(start, stop, status) ~ X + Y + Z, data=data1)
and the psm function in package
2008 Apr 08
1
Weibull maximum likelihood estimates for censored data
Hello!
I have a matrix with data and a column indicating whether it is censored
or not. Is there a way to apply weibull and exponential maximum
likelihood estimation directly on the censored data, like in the paper:
Backtesting Value-at-Risk: A Duration-Based Approach, P Chrisoffersen
and D Pelletier (October 2003) page 8?
The problem is that if I type out the code as below the likelihood
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
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
2004 May 21
1
interval-censored data in coxph
Hi,
I am wondering how to specify interval-censored data
in coxph? The example in the help page
summary(coxph(Surv(start, stop, event) ~ x, data =
test2))
is for counting process data, is the counting process
data the same as interval-censored data?
Thanks
__________________________________
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 <-
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
2008 Jun 13
2
Maximum likelihood estimation in R with censored Data
Hello,
I'm trying to calculate the Maximum likelihood estimators for a dataset
which contains censored data.
I started by using the function "nlm", but isn't there a separate method
for doing this for e.g. the "weibull" and the "log-normal" distribution?
Thanks,
Olivia
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2003 Jun 11
1
mixed-effects models for left-censored data?
Dear R-helpers,
excuse me if this is not exclusively an R-related question.
I have data from a nested design, both temporally and spatially, and the reponse variable of interest is left-censored. That is, only values > "some treshold" are available, otherwise "LOW" is reported.
Are there ways of building a linear model with both fixed and random effects, when the
2008 Jan 13
1
How to fit a Tobit model with observations censored at different values
Dear everyone:
I am a new user of R. I have a dataset with a dependent variable (DV) censored at different values. The dataset looks like,
conditions .....IDV1 IDV2 DV
1 2 4 89
1 6 6 75
1 4 5 0 ( DV<=70)
......
2 3 5 15
2 5 5 0
2012 Aug 31
3
fitting lognormal censored data
Hi ,
I am trying to get some estimator based on lognormal distribution when we have left,interval, and right censored data. Since, there is now avalible pakage in R can help me in this, I had to write my own code using Newton Raphson method which requires first and second derivative of log likelihood but my problem after runing the code is the estimators were too high. with this email ,I provide
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
2010 Jul 07
1
Appropriateness of survdiff {survival} for non-censored data
I read through Harrington and Fleming (1982) but it is beyond my
statistical comprehension. I have survival data for insects that have
a very finite expiration date. I'm trying to test for differences in
survival distributions between different groups. I understand that
the medical field is most often dealing with censored data and that
survival analysis, at least in the package survival,
2002 Nov 13
2
survreg (survival) reports erroneous results for left-censored data (PR#2287)
Full_Name: Tim Cohn
Version: 1.6.1
OS: Macintosh OS X
Submission from: (NULL) (130.11.34.250)
The Mac version of survreg does not handle left-censored data correctly (at
least the results are not what I get doing it other ways, and they are not the
same as I get running R 1.6.1 in Windows 98se; the Windows 98 results are
correct). On the windows version of R 1.6.1.
>
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
2006 Nov 01
1
Fitting mean and covariance of Multivariate normal with censored data
Hello,
I have been googling for 2 days and I cannot find the answer in
previous posts.
I have a set of d-dimensional data elements (d=11 .. 14), each data
point can be censored at different values both
Lower-limit and upper limit.
N = 2000 sets of vectors of
D=11 data points per vector.
Each of the N*D points can have different upper and lower limits.
I "simply" want to fit a