Displaying 20 results from an estimated 1000 matches similar to: "Estimate and plot hazard function using "muhaz" package"
2009 Mar 30
1
Possible bug in summary.survfit - 'scale' argument ignored?
Hi all,
Using:
R version 2.8.1 Patched (2009-03-07 r48068)
on OSX (10.5.6) with survival version:
Version: 2.35-3
Date: 2009-02-10
I get the following using the first example in ?summary.survfit:
> summary( survfit( Surv(futime, fustat)~1, data=ovarian))
Call: survfit(formula = Surv(futime, fustat) ~ 1, data = ovarian)
time n.risk n.event survival
2011 Jun 24
1
UnoC function in survAUC for censoring-adjusted C-index
Hello,
I am having some trouble with the 'censoring-adjusted C-index' by Uno et al, in the package survAUC. The relevant function is UnoC.
The question has to do with what happens when I specify a time point t for the upper limit of the time range under consideration (we want to avoid using the right-end tail of the KM curve).
Copying from the example in the help file:
TR <-
2009 Nov 13
2
survreg function in survival package
Hi,
Is it normal to get intercept in the list of covariates in the output of survreg function with standard error, z, p.value etc? Does it mean that intercept was fitted with the covariates? Does Value column represent coefficients or some thing else?
Regards,
-------------------------------------------------
tmp = survreg(Surv(futime, fustat) ~ ecog.ps + rx, ovarian,
2018 May 24
1
Predictions from a Cox model - understanding centering of binary/categorical variables
Dear all,
I am using R 3.4.3 on Windows 10. I am preparing some teaching materials and I'm having trouble matching the by-hand version with the R code.
I have fitted a Cox model - let's use the ovarian data as an example:
library(survival)
data(ovarian)
ova_mod <- coxph(Surv(futime,fustat)~age+rx,data=ovarian)
If I want to make predict survival for a new set of individuals at 100
2005 Nov 27
1
the output of coxph
Dear All:
I have some questions about the output of coxph.
Below is the input and output:
----------------------------------------
> coxph(formula = Surv(futime, fustat) ~ age + rx + ecog.ps, data =
+ ovarian, x = TRUE)
Call:
coxph(formula = Surv(futime, fustat) ~ age + rx + ecog.ps, data =
ovarian, x = TRUE)
coef exp(coef) se(coef) z p
age 0.147 1.158
2009 Feb 06
1
Using subset in validate() in Design, what is the correct syntax?
Hi
I am trying to understand how to get the validate() function in Design
to work with the subset option. I tried this:
ovarian.cph=cph(Surv(futime, fustat) ~ age+factor(ecog.ps)+strat(rx),
time.inc=1000, x=T, y=T, data=ovarian)
validate(ovarian.cph)
#fine when no subset is used, but the following two don't work:
> validate(ovarian.cph, subset=ovarian$ecog.ps==2)
Error in
2009 Apr 14
1
Function call error in cph/survest (package Design)
Dear UseR,
I do not know if this a problem with me, my data or cph/survest in package
design. The example below works with a standard data set, but not with my
data, but I cannot locate the problem.
Note that I am using an older package of survival to avoid a problem with
the newly renamed function in survival meeting Design.
Dieter
# First, check standard example to make sure
library(Design)
2010 Oct 30
1
two group cox model
Dear all,
I am doing
library(survival)
fit <- coxph(Surv(futime,fustat) ~ rx, ovarian)
plot(survfit(fit,newdata=ovarian),col=c(1,2))
legend("bottomleft", legend=c("rx = 0", "rx = 1"),
lty=c(1,2),col=c(1,2))
Is this correct to compare these two groups? Is the 0.31 the p-value that
the median f two groups are equal
Why lty does not work here?
Many thanks
2009 Aug 01
2
Cox ridge regression
Hello,
I have questions regarding penalized Cox regression using survival
package (functions coxph() and ridge()). I am using R 2.8.0 on Ubuntu
Linux and survival package version 2.35-4.
Question 1. Consider the following example from help(ridge):
> fit1 <- coxph(Surv(futime, fustat) ~ rx + ridge(age, ecog.ps, theta=1), ovarian)
As I understand, this builds a model in which `rx' is
2012 Jun 28
3
Sobre survival analysis
Hola
Estoy tratando de correr un survival analysis usando un Cox regression model.
Tengo una duda respecto a la organizacion del script. Tengo una variable que es -tamano del individuo- y quiero ver si hay diferencia en sobrevivencia respecto a tamano. Como diseno de campo los tamanos fueron ubicados de forma aleatoria en bloques al azar.
Cuado planteo el script tengo algo como:
2005 Sep 13
1
coxph.detail() does not work
Hello everyone,
I tried to use coxph.detail() to get the hazard function. But a warning
messge always returns to me, even in the example provided by its help
document:
> ?coxph.detail
> fit <- coxph(Surv(futime,fustat) ~ age + rx + ecog.ps, ovarian, x=TRUE)
> fitd <- coxph.detail(fit)
Warning message:
data length [37] is not a sub-multiple or multiple of the number of
rows
2009 Feb 16
1
How do i compute predicted failure time from a cox model?
Given a cox model:
library(Hmisc); library(survival); (library(Design);
cox.model=cph(Surv(futime, fustat) ~ age, data=ovarian, surv=T)
str(cox.model)
What I need is the total estimated time until failure (death), not the
probability of failing at a given time (survival probability), or hazard
etc, which is what I get from survest and predict for example.
I suspect the answer 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)*
2012 Nov 27
4
Fitting and plotting a coxph with survfit, package(surv)
Hi Dear R-users
I have a database with 18000 observations and 20 variables. I am running
cox regression on five variables and trying to use survfit to plot the
survival based on a specific variable without success.
Lets say I have the following coxph:
>library(survival)
>fit <- coxph(Surv(futime, fustat) ~ age + rx, data = ovarian)
>fit
what I am trying to do is plot a survival
2006 Dec 21
1
: newbie estimating survival curve w/ survfit for coxph
I am wondering how to estimate the survival curve for a particular case(s)
given a coxph model
using this example code:
#fit a cox proportional hazards model and plot the
#predicted survival curve
fit <- coxph(
Surv(futime,fustat)~resid.ds+strata(rx)+ecog.ps+age,data=ovarian[1:23,])
z <- survfit(fit,newdata=ovarian[24:26,],individual=F)
zs <- z$surv
zt <-
2009 Feb 25
3
survival::survfit,plot.survfit
I am confused when trying the function survfit.
my question is: what does the survival curve given by plot.survfit mean?
is it the survival curve with different covariates at different points?
or just the baseline survival curve?
for example, I run the following code and get the survival curve
####
library(survival)
fit<-coxph(Surv(futime,fustat)~resid.ds+rx+ecog.ps,data=ovarian)
2010 Oct 27
2
coxph linear.predictors
I would like to be able to construct hazard rates (or unconditional death prob) for many subjects from a given survfit.
This will involve adjusting the ( n.event/n.risk)
with (coxph object )$linear.predictors
I must be having another silly day as I cannot reproduce the linear predictor:
fit <- coxph(Surv(futime, fustat) ~ age, data = ovarian)
fit$linear.predictors[1]
[1] 2.612756
2007 May 16
2
log rank test p value
How can I get the Log - Rank p value to be output?
The chi square value can be output, so I was thinking if I can also have the
degrees of freedom output I could generate the p value, but can't see how to
find df either.
> (survtest <- survdiff(Surv(time, cens) ~ group, data = surv,rho=0))
Call:
survdiff(formula = Surv(time, cens) ~ group, data = surv, rho = 0)
N Observed
2011 Jul 10
1
Package "survival" --- Difference of coxph strata with subset?
[code]>require("survival")
> coxph(Surv(futime,fustat)~age + strata(rx),ovarian)
Call:
coxph(formula = Surv(futime, fustat) ~ age + strata(rx), data = ovarian)
coef exp(coef) se(coef) z p
age 0.137 1.15 0.0474 2.9 0.0038
Likelihood ratio test=12.7 on 1 df, p=0.000368 n= 26, number of events= 12
> coxph(Surv(futime,fustat)~age, ovarian, subset=rx==1)
2007 Dec 07
1
Make natural splines constant outside boundary
Hi,
I'm using natural cubic splines from splines::ns() in survival
regression (regressing inter-arrival times of patients to a queue on
queue size). The queue size fluctuates between 3600 and 3900.
I would like to be able to run predict.survreg() for sizes <3600 and
>3900 by assuming that the rate for <3600 is the same as for 3600 and
that for >4000 it's the same as for