Displaying 20 results from an estimated 1000 matches similar to: "expected risk from coxph (survival)"
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),
2007 Dec 09
2
Getting estimates from survfit.coxph
Dear all,
I'm having difficulty getting access to data generated by survfit and
print.survfit when they are using with a Cox model (survfit.coxph).
I would like to programmatically access the median survival time for
each strata together with the 95% confidence interval. I can get it on
screen, but can't get to it algorithmically. I found myself examining
the source of print.survfit to
2007 Feb 05
2
Two ways to deal with age in Cox model
I hope one and all will allow a stats question:
When running a cox proportional hazards model ,there are two ways to
deal with age,
including age as a covariate, or to include age as part of the
follow-up time, viz,
Age as a covariate:
tetest1 <- list(time= c(4, 3,1,1,2,2,3),
status=c(1,NA,1,0,1,1,0),
age= c(0, 2,1,1,1,0,0),
2011 Mar 09
2
Anomaly with unique and match
I stumbled onto this working on an update to coxph. The last 6 lines
below are the question, the rest create a test data set.
tmt585% R
R version 2.12.2 (2011-02-25)
Copyright (C) 2011 The R Foundation for Statistical Computing
ISBN 3-900051-07-0
Platform: x86_64-unknown-linux-gnu (64-bit)
# Lines of code from survival/tests/singtest.R
> library(survival)
Loading required package: splines
2004 Nov 19
2
function 'vcov' for coxph in R 2.0.0
Hi there,
After I fitted a cox model, I used vcov to obtain the
variance of the parameter estimate. It worked correctly in
R 1.9.1. But it failed in R 2.0.0 and the error message is
Error in vcov(cox.1) : no applicable method for "vcov"
I don't know if it is a bug or there is some update on
this function. Thanks!
Lei Liu
Assistant Professor
Division of Biostatistics and
2009 Jan 06
2
Strange error message
I'm testing out some changes to survreg and got the following output, the
likes of which I've never seen before:
----------------------------------------------------------------------
R version 2.7.1 (2008-06-23)
Copyright (C) 2008 The R Foundation for Statistical Computing
ISBN 3-900051-07-0
R is free software and comes with ABSOLUTELY NO WARRANTY.
You are welcome to redistribute it
2011 Mar 22
1
help need on working in subset within a dataframe
Dear R-experts
Execuse me for an easy question, but I need help, sorry for that.
>From days I have been working with a large dataset, where operations are
needed within a component of dataset. Here is my question:
I have big dataset where x1:.....x1000 or so. What I need to do is to work
on 4 consequite variables to calculate a statistics and output. So far so
good. There are more vector
2004 Sep 03
1
Printing output on Plot
Hi,
I'm trying to print the p-values from the output of a CPH test onto a
Kaplan Meier plot. Can this be done? I only really want the p-values
from the CPH test to appear but if this can't be done I am willing to
have the entire CPH output.
This is what I am currently trying: (it doesn't print the CPH output)
plot_KM <- function(field)
{
library(survival)
y =
2010 Nov 19
4
calculating martingale residual on new data using "predict.coxph"
Hi list,
I was trying to use "predict.coxph" to calculate martingale residuals on a test
data, however, as pointed out before
http://tolstoy.newcastle.edu.au/R/e4/help/08/06/13508.html
predict(mycox1, newdata, type="expected") is not implemented yet. Dieter
suggested to use 'cph' and 'predict.Design', but from my reading so far, I'm not
sure they can
1997 Apr 08
1
R-alpha: rbind
rbind() does something strange to dimnames
R : Copyright 1997, Robert Gentleman and Ross Ihaka
Version 0.50 Beta (April 1, 1997)
R is free software and comes with ABSOLUTELY NO WARRANTY.
You are welcome to redistribute it under certain conditions.
Type "license()" for details.
> test1 <- data.frame(time= c(4, 3,1,1,2,2,3),
+ status=c(1,NA,1,0,1,1,0),
+ x= c(0,
2013 Nov 14
1
issues with calling predict.coxph.penal (survival) inside a function
Thanks for the reproducable example. I can confirm that it fails on my machine using
survival 2-37.5, the next soon-to-be-released version,
The issue is with NextMethod, and my assumption that the called routine inherited
everything from the parent, including the environment chain. A simple test this AM showed
me that the assumption is false. It might have been true for Splus. Working this
2018 Apr 25
0
Fitting survival trees with competing risk
Dear all,
I'm interested in fitting survival trees with competing risk analysis.
The tree should show the cumulative incidence function for each terminal
node .
I read several paper illustrating this possibility, but to the best of my
knowledge no R code are reported.
There is any R package for this fit?
Thank you very much in advance.
Mario Petretta
2010 Nov 18
3
Plotting number of patients at risk below survival curve
Dear list,
does anyone know of a R-package that has implemented the increasingly popular
inclusion of the number of patients at risk below Kaplan-Meier curves like in
http://bloodjournal.hematologylibrary.org/content/vol116/issue19/images/large/zh89991058760001.jpeg
any hint (or negative answer) is much appreciated.
Thanks
Thorsten
--
Thorsten Raff
2nd Medical Department,
University
2018 Mar 02
1
Variable centring within "predict.coxph"
Dear R-help,
I am using R-3.3.2 on Windows 10. I teach on a course which has 4 computer practical sessions related to the development and validation of clinical prediction models. These are currently written for Stata and I am in the process of writing them for use in R too (as I far prefer R to Stata!)
I notice that predictions made from a Cox model in Stata are based on un-centred variables,
2005 Nov 21
0
Function comparable to cutpt.coxph from "Survival Analysis using S"
The title says it all really; I am looking for a function along the lines of
cutpt.coxph as described in "Survival Analysis Using S" (Tableman and
Kim), Chapter 6. As may be guessed, the function optimises the
cutpoint of a continuous variable for cox proportional hazard
modelling. I can't find it, or any similar function, on CRAN.
Alternatively, perhaps there is a way of extracting
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)
2009 Jul 13
0
adjusting survival using coxph
I have what I *think* should be a simple problem in R, and hope
someone might be able to help me.
I'm working with cancer survival data, and would like to calculate
adjusted survival figures based on the age of the patient and the
tumour classification. A friendly statistician told me I should use
Cox proportional hazards to do this, and I've made some progress with
using the
2010 Feb 16
1
survival - ratio likelihood for ridge coxph()
It seems to me that R returns the unpenalized log-likelihood for the ratio likelihood test when ridge regression Cox proportional model is implemented. Is this as expected?
In the example below, if I am not mistaken, fit$loglik[2] is unpenalized log-likelihood for the final estimates of coefficients. I would expect to get the penalized log-likelihood. I would like to check if this is as expected.
2010 Dec 02
0
survival - summary and score test for ridge coxph()
It seems to me that summary for ridge coxph() prints summary but returns NULL. It is not a big issue because one can calculate statistics directly from a coxph.object. However, for some reason the score test is not calculated for ridge coxph(), i.e score nor rscore components are not included in the coxph object when ridge is specified. Please find the code below. I use 2.9.2 R with 2.35-4 version
2006 Dec 22
0
newbie estimating survival curve w/ survfit for coxph
fit <- coxph(Surv(futime,fustat)~ age +strata(rx), data=ovarian,
subset=1:23)
curves <- survfit(fit, newdata=ovarian[24:26,])
I don't think this is mentioned in the documentation (I'll have to fix that!),
but subscripting works for survfit objects. In this case there are 2 strata
and 3 subjects, and
curves[1,2] will return the survival curve for strata 1,