Displaying 6 results from an estimated 6 matches for "obstime".
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abstime
2003 Mar 12
1
simulating 'non-standard' survival data
...pages={245-252}
}
######################?
Code to simulate survival data under complex situations (MacKenzie and
Abrahamowicz, Statistics and Computing 2002)
#######################
#sample size
n<-100
R<-1:n
#explanatory variable
x<-runif(n,3,9)
#survival time and censoring variable:
obsTime<-rexp(n,1)
status<-ifelse(runif(n)>.2,1,0)
obsTime<-obsTime[order(obsTime)]
status<-status[order(obsTime)]
dati<-matrix(-99,n,(1+2))
#hazard ratio as function of the explanatory variable xx, and survival time.
HR<-function(ttime,xx){exp(.5)} #.5 is the log hazard ratio
P<-...
2006 Sep 03
2
Running cox models
...atistics/chapter16.html
(Primary Biliary Cirrhosis data link at top of the page),
I'm using the following code:
--------------- start of code
library(survival)
liver <- scan("liver2.txt",list(age=0,albumin=0,alkphos=0,ascites=0,bili=0,
cholest=0,edema=0,edmadj=0,hepmeg=0,obstime=0,platelet=0,protime=0,
sex=0,sgot=0,spiders=0,stage=0,status=0,treatmnt=0,
triglyc=0,urinecu=0))
fit<-coxph(Surv(obstime,status)~bili+edmadj+albumin+protime+age,data=liver)
summary(fit)
----------------- End of code
but the answer is rather different from that in the book (p.68...
2007 Nov 07
1
Aggregate with non-scalar function
R-Helpers,
I'm sorry to have to ask this -- I've not used R very much in the last
8 or 10 months, and I've gotten rusty.
I have the following (ff2 is a subset of a much, much larger dataset):
> ff2
hostName user sys idle obsTime
10142 fred 0.4 0.5 98.0 2007-11-01 02:02:18
16886 barney 0.5 0.2 94.6 2007-10-25 19:12:12
8795 fred 0.0 0.1 99.8 2007-10-30 05:08:22
5261 fred 0.1 0.2 99.7 2007-10-25 07:20:32
12427 barney 0.1 0.2 93.2 2007-10-19 14:34:10
18067 barney 0.1 0.2 99.4 2007-10-27 10:34:08
973...
2010 Mar 15
3
the problem about sample size
Hi all:
I am a user of "JM" package.
Here's the problem of "sample size".
The warning is:
Error in jointModel(fitLME, fitSURV_death, timeVar = "time", method = "piecewise-PH-GH") :
sample sizes in the longitudinal and event processes differ.
According to the suggestion of "missing data",I use the same data set(data_JM) without any
2008 Aug 22
0
Censored Poisson Data
...son regression on
counting data which include censored observations, that is, observations of the form
"2 events or more" or "less than 2 events" or even "1 or 2 events".
Can anyone give me a hint whether this is already possible and how to do it?
Data of the form (obstime is the observation time, "offset" in Poisson
regression):
obs obstime cmin cmax
1 1 2 Inf
2 2 0 1
3 1 1 2
and so on.
Best wishes,
Justine
--
2006 Aug 08
1
Fitting data with optim or nls--different time scales
Hi,
I have a system of ODE's I can solve with lsoda.
Model=function(t,x,parms)
{
#parameter definitions
lambda=parms[1]; beta=parms[2];
d = parms[3]; delta = parms[4];
p=parms[5]; c=parms[6]
xdot[1] = lambda - (d*x[1])- (beta*x[3]*x[1])
xdot[2] = (beta*x[3]*x[1]) - (delta*x[2])
xdot[3] = (p*x[2]) - (c*x[3])
return(list(xdot))
}
I want