Displaying 20 results from an estimated 1000 matches similar to: "some question about partial prediction in survival"
2009 Feb 17
3
Survival-Analysis: How to get numerical values from survfit (and not just a plot)?
Hi!
I came across R just a few days ago since I was looking for a toolbox
for cox-regression.
I?ve read
"Cox Proportional-Hazards Regression for Survival Data
Appendix to An R and S-PLUS Companion to Applied Regression" from John Fox.
As described therein plotting survival-functions works well
(plot(survfit(model))). But I?d like to do some manipulation with the
survival-functions
2008 Mar 13
1
survival curve for only certain values of a factor
Hello:
Using the built-in dataset aml as an example:
data(aml)
If I use instead dummy variables:
aml$x1 = (aml$x=="maintained")aml$x2 = (aml$x=="unmaintained")
and I want to plot the survival curve using x1, x2, and I just want the 2 levels, rather than 4 curves from:
fit <- survfit(Surv(time, status) ~ x1+x2, data=aml)
plot(fit)
I guess because there are 2 levels
2006 Jun 10
1
Calculating survival for set time intervals
Hello friends and fellow R users,
I have successfully tabulated and entered my survival data into R and
have generated survival curves. But I would like to be able to determine
what the survival rates are now at one month, three months, six months
and one year.
I have a data set, via.wall, which I have entered into R, and which
generates the following Surv object:
Surv(Days,Status==1)
[1]
2006 Jul 11
2
new object
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2011 Apr 18
1
time dependent hazard ratios
Hi, I am new to time-dependent Cox model to estimate time dependent hazard
ratios. Let me use aml dataset from survival package:
> aml3<-survSplit(aml2,cut=c(5,10,20),end="time",start="start",
event="status",episode="i")
If I want to esimate hazard ratio for each of the time intervals 0-5, 5-10,
10-20 and >=20, would the following calculate
2008 Jun 07
1
expected risk from coxph (survival)
Hello,
When I try to to obtain the expected risk for a new dataset using coxph in the survival package I get an error. Using the example from ?coxph:
> test1 <- list(time= c(4, 3,1,1,2,2,3),+ status=c(1,NA,1,0,1,1,0),+ x= c(0, 2,1,1,1,0,0),+ sex= c(0, 0,0,0,1,1,1))> cox<-coxph( Surv(time, status) ~ x + strata(sex), test1)
2006 Jan 20
3
command in survival package
Hi there,
I have a question about one command sentence when I follow the example
in the book of "Survival analysis in S":
> aml1<-aml[aml$group==1]
but I got the error warning: NULL data frame with 23 rows
Thus, I couldn't keep going on the next command:
esf.fit<-survfit(Surv(aml1,status)~1).
and also when I try
> aml1<-aml[aml$group==1,]
2008 Mar 18
1
how to reset slogic.f file
Hi there:
recently i try to use LogicReg package for a tree model(logistics fit )
. i list my code and error below:
> dim(model.dat)
[1] 48000 745
> fit1 <- logreg(resp = model.dat[,745], bin=model.dat[, 9:700], type = 3,
select = 3, ntrees = c(1,2), nleaves=c(1,7), )
Insufficient declaration
LGCn1MAX in logreg() is 20000
LGCn1MAX should be at least 48000
Please fix and
2010 Dec 27
1
Problem using pkg "survival"
Hello all.
I've been attempting to utilize the "survival" pkg (
http://cran.r-project.org/web/packages/survival/index.html), while reading
through this guide (http://www.ms.uky.edu/~mai/Rsurv.pdf). I figured working
through the guide would be the best way to go, before attempting my own
data.
I tried to utilize the Kaplain-Meier estimator as shown in the guide:
2001 Sep 18
1
case weights in coxph (survival)
Hi,
I am having trouble with the survival library, particualrily the coxph
function.
the following works
coxph(jtree9$cph.call,z,rep(1,dim(z)[1]))
Call:
coxph(formula = jtree9$cph.call, data = z, weights = rep(1, dim(z)[1]))
coef exp(coef) se(coef) z p
SM 0.2574 1.294 0.0786 3.274 1.1e-03
Sex -0.1283 0.880 0.1809 -0.709
2006 May 05
2
How to access results of survival analysis
Hi List,
A friend of mine recently asked the same question as Heinz T?chler. Since
I've already written the code I'd like to share with the list.
# x is an object returned by "survfit";
# "smed" returns a matrix of 5 columns of
# n, events, median, 0.95LCL, 0.95UCL.
# The matrix returned has rownames as the
# group labels (eg., treatment arms) if any.
smed <-
2007 Jun 17
1
error bars on survival curve
I am using plot(survfit(Surv(time,status) ~...) and would like to add
error bars rather than the confidence intervals. Am I able to do this
at specified times? e.g. when time = 20 & 40.
leukemia.surv <- survfit(Surv(time, status) ~ x, data = aml)
plot(leukemia.surv, lty = 2:3,xlim = c(0,50))
#can i add error bars at times 20 & 40?
legend(100, .9, c("Maintenance", "No
2010 Sep 23
2
extending survival curves past the last event using plot.survfit
Hello,
I'm using plot.survfit to plot cumulative incidence of an event.
Essentially, my code boils down to:
cox <-coxph(Surv(EVINF,STATUS) ~ strata(TREAT) + covariates, data=dat)
surv <- survfit(cox)
plot(surv,mark.time=F,fun="event")
Follow-up time extends to 54 weeks, but the last event occurs at week
30, and no more people are censored in between. Is there a
2009 Nov 06
1
Survival Plot in R 2.10.0
I would like to produce a complimentary log-log survival plot with
only the points appearing on the graph. I am using the code below,
taken from the plot.survfit page of help for the the survival package
(version 2.35-7).
I am running in R 2.10.0 on Windows XP, and the list of packages
following
the error is loaded. Is there some specific 'type= ' syntax, or an
additional parameter
that
2011 Mar 15
1
Questions on dividing lists and tapply
Hello R community,
I have two questions about using R.
The first is about dividing each element of a list with another similar
sized list. So, if the first list has two elements and so does the second,
then the result should also be a list with two elements.
For example, the inputs are:
list(matrix(1:6,ncol=2),matrix(1:6,ncol=2))->l1
l2<-list(1:3,2)
I want to get a list, l3 with the
2008 Dec 11
1
How to generate a prediction equation for a stratified survival model that was fitted by cph() in Design package
Dear all,
I used cph() function from Frank harrell's Design package to create a
survival model, then used functions 'Function' and 'sascode' to generate
prediction equation based on the saved survival model. But it failed. I
included a stratified variable in the model. If I removed the
stratification, they were working well. Does that mean that function
'Function'
2012 Oct 08
1
Survival prediction
> Dear All,
>
> I have built a survival cox-model, which includes a covariate * time interaction. (non-proportionality detected)
> I am now wondering how could I most easily get survival predictions from my model.
>
> My model was specified:
> coxph(formula = Surv(event_time_mod, event_indicator_mod) ~ Sex +
> ageC + HHcat_alt + Main_Branch + Acute_seizure +
2010 Aug 31
1
Speeding up prediction of survival estimates when using `survifit'
Hi,
I fit a Cox PH model to estimate the cause-specific hazards (in a competing risks setting). Then , I compute the survival estimates for all the individuals in my data set using the `survfit' function. I am currently playing with a data set that has about 6000 observations and 12 covariates. I am finding that the survfit function is very slow.
Here is a simple simulation example
2001 Nov 29
0
a patch to tapply (PR#1186)
Though tapply(x, factor, fun, simplify =TRUE) should be equivalent to
sapply(split(x, factor), fun, simplify=TRUE), note simplify=TRUE, it is not
so if fun() returns a vector rather than a scalar, e.g.
> tapply(1:6, c(0,0,0,1,1,1), function(x) c(min=min(x), max=max(x)),
simplify=TRUE)
$"0"
min max
1 3
$"1"
min max
4 6
> sapply(split(1:6, c(0,0,0,1,1,1)),
2008 Apr 07
2
basehaz and newdata
I am unable to get the basehaz function to apply a proportional
hazards model to a new data frame. I replicated my specific situation
with the example for coxph in the help, where I changed the x value of
the first record from 0 to 1. Is there something incorrect in the
syntax that I am using? Thanks in advance!
test1 <- list(time= c(4, 3,1,1,2,2,3),
status=c(1,NA,1,0,1,1,0),