Displaying 20 results from an estimated 1000 matches similar to: "tansformation of variables in cph from rms package"
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 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,
2011 Aug 01
2
How to make a nomogam and Calibration plot
Dear R users,
I am a new R user and something stops me when I try to write a academic
article. I want to make a nomogram to predict the risk of prostate cancer
(PCa) using several factors which have been selected from the Logistic
regression run under the SPSS. Always, a calibration plot is needed to
validate the prediction accuracy of the nomogram.
However, I tried many times and read a lot of
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,
2010 May 19
1
Nomogram with multiple interactions (package rms)
Dear list,
I'm facing the following problem :
A cox model with my sex variable interacting with several continuous variables : cph(S~sex*(x1+x2+x3))
And I'd like to make a nomogram. I know it's a bit tricky and one mights argue that nomogram is not a good a choice...
I could use the parameter interact=list(sex=("male","female"),x1=c(a,b,c))... but with rcs or pol
2013 Jun 24
2
Nomogram (rms) for model with shrunk coefficients
Dear R-users,
I have used the nomogram function from the rms package for a logistic
regresison model made with lrm(). Everything works perfectly (r version
2.15.1 on a mac). My question is this: if my final model is not the one
created by lrm, but I internally validated the model and 'shrunk' the
regression coefficients and computed a new intercept, how can I build a
nomogram using that
2009 Apr 25
3
Nomogram with stratified cph in Design package
Hello,
I am using Dr. Harrell's design package to make a nomogram. I was able to
make a beautiful one without stratifying, however, I will need to stratify
to meet PH assumptions. This is where I go wrong, but I'm not sure where.
Non-Stratified Nomogram:
2009 May 22
2
System crash when using surv=T in cph
Can someone help me. I am very new to R. I am fitting a Cox model using Frank
Harrell's cph as I want to produce a Nomogram. This is what I have done:
Srv<- Surv(time,cens)
f.cox<- cph(Srv~ v1+v2+v3+v4, x=T, y=T, surv=T)
As soon as I press enter, Windows XP crashes. If I remove surv=T, then it
works. I have R version 2.9.0.
Is there a way of displaying the parameter estimates (ie beta
2011 Jun 20
2
Error of Cross Validation
Dear R users:
Recently, I tried to write a program to calculate cross-validated predicted
value.
My sources are as follows. However, the R reported an error.
Could you please check the sources? Thanks.
set.seed(100)
x<-rnorm(100)
y<-sample(rep(0:1,50),replace=T)
dat<-data.frame(x,y)
library(rms)
fito<-lrm(y~x)
preo<-predict(fito)
pre<-matrix(NA,nrow=100,ncol=200)
for (i in
2009 Sep 12
2
could not find function "Varcov" after upgrade of R?
After upgrading R to 2.9.2, I can't use the anova() fuction.
It says "could not find function "Varcov" ".
What's wrong with my computer? Help needed, thanks!
Yao Zhu
Department of Urology
Fudan University Shanghai Cancer Center
No. 270 Dongan Road, Shanghai, China
[[alternative HTML version deleted]]
2011 Sep 01
1
How to retrieve bias-corrected probability from calibrate.rms
Dear R users:
In Prof. Harrell's library rms, calibrate.rms plot the Bias-corrected
Probability and Apparent Probability.
The latter one can be retrieved from class calibrate.default. But how to
retrieve the former one.
BW
*Yao Zhu*
*Department of Urology
Fudan University Shanghai Cancer Center
Shanghai, China*
[[alternative HTML version deleted]]
2011 Apr 22
2
How to answer the question about transitive correlation?
Hi, everyone. I know it may be a basic statistical question. But I can't
find a good answer.
I have a question raised by one of the reviewers.
Factor A expression was strongly correlated with B expression (chi-square)
in this series. Prior reports by the same authors showed that B expression
strongly correlated with survival (Log-rank). Please provide an explanation
why then were the results
2011 Apr 28
1
Nomograms from rms' fastbw output objects
There is both a technical and a theoretical element to my question...
Should I be able to use the outputs which arise from the fastbw function
as inputs to nomogram(). I seem to be failing at this, -- I obtain a
subscript out of range error.
That I can't do this may speak to technical failings, but I suspect it
is because Prof Harrell thinks/knows it injudicious. However, I can't
2010 Jan 21
3
cross validation function translated from stata
Hi, everyone:
I ask for help about translating a stata program into R.
The program perform cross validation as it stated.
#1. Randomly divide the data set into 10 sets of equal size, ensuring equal
numbers of events in each set
#2. Fit the model leaving out the 1st set
#3. Apply the fitted model in (2) to the 1st set to obtain the predicted
probability of a prostate cancer diagnosis.
#4. Repeat
2010 Oct 13
1
bootstrap in pROC package
Dear useRs:
I use pROC package to compute the bootstrap C.I. of AUC.
The command was as follows:
roc1<-roc(all$D,all$pre,ci=TRUE,boot.n=200)
However, the result was:
Area under the curve: 0.5903
95% CI: 0.479-0.7016 (DeLong)
Why the C.I. was computed by the Delong Method?
Yao Zhu
Department of Urology
Fudan University Shanghai Cancer Center
Shanghai, China
[[alternative HTML version
2011 Jun 02
2
Removal of elements from nomograms
The rms package includes the nomogram function, which generates a list
object that can be passed to plot for graphical production of nomograms.
I would like to remove the "linear predictor" line in the graph, which
means (I suspect) removing it from the nomogram output object. I've
looked at the nomogram output object, but it is not clear to me if or
how it might be edited to
2010 Aug 25
1
modify a nomogram
Hi,
I would like to emphasize ("zoom") the zone of a nomogram where the
probability are > 0.01
(nomogram built with nomogram, Design).
As a consequence, I don't need to draw the part of the "Total points"
axis with score < 60 equivalent in my case to a linear predictor < 4.5
- As far as I know, this is not possible with the arguments of the function.
- Changing
2013 Feb 14
1
Nomogram after Cox Random Effect (frailty) model
Dear R-users,
I am a novice R-user with some experience in using the RMS package for taking nomograms after various survival models.
This time, I am trying to plot a nomogram after a Random Effects Cox, implemented by the "coxme" package. My questions are:
1. Is it possible to take a nomogram directly after the coxme survival function?
2. If not is there a way to take the linear
2003 Dec 08
1
Design functions after Multiple Imputation
I am a new user of R for Windows, enthusiast about the many functions
of the Design and Hmisc libraries.
I combined the results of a Cox regression model after multiple imputation
(of missing values in some covariates).
Now I got my vector of coefficients (and of standard errors).
My question is: How could I use directly that vector to run programs such
as 'nomogram', 'calibrate',
2010 Dec 09
1
error in lrm( )
Dear Sir or Madam?
I am a doctor of urology,and I am engaged in developing a nomogram of bladder cancer. May I ask for your help on below issue?
I set up a dataset which include 317 cases. I got the Binary Logistic Regression model by SPSS.And then I try to reconstruct the model
?lrm(RECU~Complication+T.Num+T.Grade+Year+TS)? by R-Project,and try to internal validate the model through