Displaying 20 results from an estimated 400 matches similar to: "Fitting problem for Cox model with Strata as interaction term"
2003 Dec 17
5
beginner programming question
Hi all,
The last e-mails about beginners gave me the courage to post a question;
from a beginner's perspective, there are a lot of questions that I'm
tempted to ask. But I'm trying to find the answers either in the
documentation, either in the about 15 free books I have, either in the
help archives (I often found many similar questions posted in the past).
Being an (still actual)
2005 Oct 27
2
how to predict with logistic model in package logistf ?
dear community,
I am a beginer in R , and can't predict with logistic model in package
logistf,
could anyone help me ? thanks !
the following is my command and result :
>library(logistf)
>data(sex2)
>fit<-logistf(case ~ age+oc+vic+vicl+vis+dia, data=sex2)
>predict(fit,newdata=sex2)
Error in predict(fit, newdata = sex2) : no applicable method for
"predict"
2004 Nov 09
1
survSplit: further exploration and related topics
To Danardonos concern of splitting time for records with delayed entry:
This can fairly easily be accomodated, by simply splitting time in small
intervals of time since entry into the study, and then compute the value
of the other timescales for each of these e.g.:
current.age <- time.from.entry + age.at.entry
but the cut on the other timescales will not be exactly where you may
want
them
2008 Jun 20
1
Unexpected Behavior (potentially) in t.test
Greetings,
I have stumbled across some unexpected behavior (potential a bug) in, what I
suspect to be R's (2.6.2 on Ubuntu Linux) t.test function; then again the
problem may exist in my code. I have shutdown R and started it back up,
re-run the code and re-experienced the error. I have searched on Google for
the abnormal termination error message "(stderr < 10 * .Machine$double.eps *
2009 Jul 13
1
survSplit with data.frame containing a Surv object
Dear All,
since years I am struggling with Surv objects in data.frames. The
following seems to have to do with it.
See below the modified example from the help page of survSplit. The
original works, as expected. If, however, a Surv object is added to
the data.frame, each record gets doubled.
Is there some solution other than avoiding Surv objects in data.frames?
Thanks,
Heinz
2024 Sep 20
1
model.matrix() may be misleading for "lme" models
Dear r-devel list members,
I'm posting this message here because it concerns the nlme package,
which is maintained by R-core. The problem I'm about to describe is
somewhere between a bug and a feature request, and so I thought it a
good idea to ask here rather posting a bug report to the R bugzilla.
I was made aware (by Ben Bolker) that the car::Anova() method for "lme"
2010 Jun 21
1
Question about wine qcap v4l's MediaSampleTime
in wine/dlls/qcap/v4l.c:
ReadThread()
--> OutputPin_GetDeliveryBuffer((OutputPin *)capBox->pOut, &pSample, NULL, NULL, 0);
--> IMediaSample_SetTime(*ppSample, tStart, tStop);
in wine/dlls/quartz/memallocator.c:
StdMediaSample2_GetTime(IMediaSample2 * iface, REFERENCE_TIME * pStart, REFERENCE_TIME * pEnd)
--> if tstart/stop is NULL, leave pStart/pEnd not setted.
in
2002 Jun 07
1
filter data frames
Hello!
I'm looking for an easy way to filter data frames.
Some rows in my data frame needs to be left out,
for instance, rows with invalid data.
Right now, if I want to pair two columns of this data frame,
I have to do this:
> pairs(as.data.frame(list(tstart=df$tstart[valid],tend=df$tend.sdr[valid])))
or this:
>
2024 Sep 21
1
model.matrix() may be misleading for "lme" models
Dear list members,
After further testing, I found that the following simplified version of
model.matrix.lme(), which omits passing xlev to the default method, is
more robust. The previous version generated spurious warnings in some
circumstances.
model.matrix.lme <- function(object, ...){
data <- object$data
if (is.null(data)){
NextMethod(formula(object),
2018 May 29
1
Difficulty in writing R code for one pool dynamic model
Hi everyone,
I was trying to mode the following exercise using R.
The question: Set up a one pool model using numericintegration. The model will run from time 1 to time 30 using a time step of 1.The pool (A) will be fed by flux "inA" at a rate of 5 units per hour anddrained by flux "outA" at a rate of 20% per hour. At time 0, A has 5units. At time 30, what is the pool size of
2005 Jul 18
1
Survival dummy variables and some questions
Hi All,
I am currently conducting some survival analyses. I would like to
extract coefficients at each level of the IVs.
I read on a previous posting that dummy regression using coxph was not
possible.
Therefore I though, hey why not categorize the variables
(I realize some folks object to categorization but the paper I am
replicating appears to have done so ...)
and turn the variables
2008 Sep 06
2
Hopefully an easy error bar question
Hi im trying to add error bars to my barplots, there very basic, i have a few grapghs where the y variable is different but on all the X variable is Age (Adult and Juvenile) however this is split into two levels so i have males and females, so my graph basically has four bars on it.
I know how to add eror bars for instance when there is only one level eg lookng at the diffrence between male and
2004 Feb 18
0
[PATCH] fix tftp verbose mesage
tftp-hpa-0.35 and tftp-hpa-0.36 show wrong transmission time.
>tftp -V
tftp-hpa 0.36, with readline
>tftp -m octet -v localhost -c get aaa /tmp/aaa
Connected to localhost.localdomain (127.0.0.1), port 69
getting from localhost.localdomain:aaa to /tmp/aaa [octet]
Received 33554432 bytes in -3.3 seconds [-81407477 bit/s]
^^^^ ^^^^^^^^^
By the way, why
2011 Nov 10
3
Creating dummys in R
Dear R-project!
How do i create 1 dummy from 2 already existing dummys. To be more precise, I want to create a dummy from a dummy called "sex" and another called "sex1" when both thoose dummys are 1 I want my created dummy "samesex" to take 1.
Thanks for the help!
Paulie
[[alternative HTML version deleted]]
2006 May 17
1
question about survSplit
Dear R-users,
I use the survsplit function in the survival package to change my data into
counting-process format
and the transformed format is as follow:
(a)
start stop event DP age ....
0 5 0 1 20
5 10 0 1 20
10 25 1 1 20
looking at the above three entries that belong to the same person, if an
event happen at
2007 Apr 25
0
Use of Lexis function to convert survival data to counting format
I'm trying to convert a dataset from the time-independent analysis form
> head(addicts)
id clinic status survtime prison meth clinic01
1 1 1 1 428 0 50 1
2 2 1 1 275 1 55 1
3 3 1 1 262 0 55 1
into the "counting data format" necessary to perform extended Cox regression.
I got
2007 Oct 11
0
Cox with time varying effect
Dear R users,
I am doing Cox regression using coxph(Survival) or cph(Design).
I have time varying effects (diagnosed with schoenfeld residuals Chi2 test and graph) so I first want to split time into 2 separate intervals : t<6months and t>=6months, to estimate one hazard ratio (hr) for each interval.
I am analysing Overall survival according to 3 prognostic factors (age,deep,ldh).
2009 Mar 10
2
simple question beginner
Hi there,
I am beginner in R and I have some basic question. Suppose I run a common procedure such as a t test or cox model like below:
out<-coxph( Surv(tstart,tstop, death1) ~ x1+x1:log(tstop+1) , test1,method=c("breslow"))
Which yields the following result:
Call:
coxph(formula = Surv(tstart, tstop, death1) ~ x1 + x1:log(tstop +
1), data = test1, method =
2009 Jun 07
1
Must be a better way to collate sequenced data
I have data that looks like this
time_stamp (seconds) user_id
The data is (partial) ordered by time - in that sometimes transactions occur at the same timestamp. The output I want is collated by transaction time on a per user basis, normalized by the maximum number of transactions per user, and aggregated over each day. So, if the users have 50 transactions in the first day and 20 transactions
2013 Jan 10
1
Semi Parametric Bootstrap
Greetings to you all,
I am performing a semi parametric bootstrap in R on a Gamma Distributed
data and a Binomial distributed data. The main challenge am facing is
the fact that the residual variance depends on the mean (if I am correct).
I strongly feel that the script below may be wrong due to mean-variance
relationship
#####R code#######
fit1s