Displaying 20 results from an estimated 30000 matches similar to: "plot.validate.cph"
2011 Feb 21
2
Interpreting the example given by Prof Frank Harrell in {Design} validate.cph
Dear R-help,
I am having a problem with the interpretation of result from validate.cph in
the Design package.
My purpose is to fit a cox model and validate the Somer's Dxy. I used the
hypothetical data given in the help manual with modification to the cox
model fit. My research problem is very similar to this example.
This is the model without stratification:
> library(Design)
> f1
2011 Sep 06
1
calibrate.cph plots
Hi!
How can I exclude the legends from calibration plots
generated by calibrate.cph
regards,
Salvo
[[alternative HTML version deleted]]
2007 Aug 27
2
validate (package Design): error message "subscript out of bounds"
Dear R users
I use Windows XP, R2.5.1 (I have read the posting guide, I have
contacted the package maintainer first, it is not homework).
In a research project on renal cell carcinoma we want to compute
Harrell's c index, with optimism correction, for a multivariate
Cox regression and also for some univariate Cox models.
For some of these univariate models I have encountered an error
2011 Aug 20
1
val.surv
Dear R-users,
I have two questions regarding validation and calibration of Survival regression models.
1. I am trying to calibrate and validate a cox model using val.surv.
here is my code:
f.1<-cph(Surv(time,event)~age, x=T, y=T, data=train)
test1<-test[,"age"]
val.surv(f.1, newdata=data.frame(test1), u=10)
but I get an error message:
Error in val.surv(f.1, newdata
2011 Feb 25
1
Forced inclusion of varaibles in validate command as well as step
Hello all
I am a very new R user
I am used to using STATA
My problem:
I want to build a Cox model and validate this.
I have a large number of clinical relevant factors and feel the need to
reduce these. Meanwhile I have some clinical variables I deem sufficiently
important to force into the model regardless of AIC or p value.
This is my present log over commands
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
1997 Oct 18
0
R-alpha: This weeks bugs and requests for enhancements
Here's a number of items that came up in connection with my course for
medical ph.d. students this week:
boxplot():
- deals ungracefully with empty groups and factor levels not
present in grouping variable.
- no indication of what variable is being plotted
data.entry() (mostly W95 rseptbeta problems)
- Entry of first variable name doesn't take before 2nd
2011 Feb 19
0
contrasting Somer's D from Design package
Dear R help,
I am having a problem with the Design package and my problem is detailed
here.
I fit a cox model to my data and validate the Somer's Dxy using the Design
package.
(Because of computation time problem, i only try 10 bootstrap samples for
the time being)
This is the model without stratification:
> library(Design)
>
2010 May 22
0
Modeling time varying effects in with cph: how to ?
Dear R users,
I know, this is the second time i return on this topic. Sorry, but this
analysis is of great value for me, and i hope someone can help me.
I need to model a time-varying effect in a Cox model. Briefly explained
here:
http://books.google.com/books?id=9kY4XRuUMUsC&lpg=PP1&hl=it&pg=PA147#v=onepage&q&f=false
2013 Jul 11
0
[R-pkgs] Major Update to rms package
The rms ("Regression Modeling Strategies") package has undergone a
massive update. The entire list of updates is at the bottom of this
note. CRAN has the update for linux and will soon have it for Windows
and Mac - check http://cran.r-project.org/web/packages/rms/ for
availability. This rms update relies on a major update of the Hmisc
package.
The most user-visible changes are:
2007 Feb 15
1
bootcov and cph error
Hi all,
I am trying to get bootstrap resampled estimates of covariates in a Cox
model using cph (Design library).
Using the following I get the error:
> ddist2.abr <- datadist(data2.abr)
> options(datadist='ddist2.abr')
> cph1.abr <- cph(Surv(strt3.abr,loc3.abr)~cov.a.abr+cov.b.abr,
data=data2.abr, x=T, y=T)
> boot.cph1 <- bootcov(cph1.abr, B=100, coef.reps=TRUE,
2011 Nov 29
2
Nomogram with stratified cph in Design package-- failure probability
Hello,
I am using Dr. Harrell's design package to make a nomogram. I was able to
make a beautiful one. However, I want to change 5-year survival probability
to 5-year failure probability.
I couldn?t get hazard rate from Hazard(f1) because I used cph for the model.
Here is my code:
f1 <- cph(Surv(retime,dfs) ~
age+her2+t_stage+n_stage+er+grade+cytcyt+Cyt_PCDK2 , data=data11,
surv=T,
2006 Apr 11
1
cph() in Design package
Hi there, I encountered a weird problem using cph()
with Design package:
I have 2 datasets, say "dat1" and "dat2", both data
frames with 3 columns "time","status" and "scores",
all numeric
If I run the following:
dd<-datadist(dat1)
options(datadist='dd')
dd
time status scores
Low:effect 37.0 0 -6.018
2011 Nov 30
1
Nomogram with stratified cph in rms package, how to get failure probability
Hello,
I am using Dr. Harrell's rms package to make a nomogram. I was able to make
a beautiful one. However, I want to change 5-year survival probability to
5-year failure probability.
I couldn?t get hazard rate from Hazard(f1) because I used cph for the model.
Here is my code:
library(rms)
f1 <- cph(Surv(retime,dfs) ~
age+her2+t_stage+n_stage+er+grade+cytcyt+Cyt_PCDK2 , data=data11,
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)
2013 Apr 11
0
PHP Markdown Lib 1.3
This is the first release of PHP Markdown Lib. This package requires PHP version 4.3 or later and is designed to work with PSR-0 autoloading and, optionally, with Composer. You can download it from the PHP Markdown website:
<http://michelf.ca/projects/php-markdown/>
You can also read the official announcement here:
<http://michelf.ca/blog/2013/php-markdown-lib/>
Also note new
2009 Jul 15
0
Nagelkerkes R2N
I am interested Andrea is whether you ever established why your R2 was 1.
I have had a similar situation previously.
My main issue though, which I'd be v grateful for advice on, is why I am obtaining such negative values -0.3 for Somers Dxy using validate.cph from the Design package given my value of Nagelkerke R2 is not so low 13.2%.
I have this output when fitting 6 variables all with
2011 Oct 21
1
cph/nomogram Design/RMS package hazard ratio: interquartile vs per unit
Hello,
I am constructing a nomogram using cph and nomogram commands in Dr.
Harrell's Design/RMS package. The HR that I obtain for dichotomous and
categorical variables are identical to those that I obtain using STATA
stcox. However, the inter-quartile HR I obtain for continuous variables is
obviously different, since STATA gives me HR for each unit (year,
centimeter, etc) like coxph would
2011 Mar 07
0
survest() for cph() in Design package
Hi, I am trying to run a conditional logistic model on a nested case-control
study using cph() and then estimate survival based on the model. The data came
from Prof Bryan Langholz website where he also has the SAS code to this, so I am
trying to replicate the SAS results.
The data attached. Basically, the variables are:
rstime: risk set age
rsentry: fake entry time, just before rstime
setno:
2011 Aug 25
1
survplot() for cph(): Design vs rms
Hi, in Design package, a plot of survival probability vs. a covariate can be generated by survplot() on a cph object using the folliowing code:
n <- 1000
set.seed(731)
age <- 50 + 12*rnorm(n)
label(age) <- "Age"
sex <- factor(sample(c('male','female'), n, TRUE))
cens <- 15*runif(n)
h <- .02*exp(.04*(age-50)+.8*(sex=='Female'))
dt <-