[R] Extracting approximate Wald test (Chisq) from coxph(..frailty)

2007-04-17 Thread Mohammad Ehsanul Karim
Dear List,

How do I extract the approximate Wald test for the
frailty (in the following example 17.89 value)?

What about the P-values, other Chisq, DF, se(coef) and
se2? How can they be extracted?

##
kfitm1
Call:
coxph(formula = Surv(time, status) ~ age + sex +
disease + frailty(id, 
dist = gauss), data = kidney)

  coef se(coef)
age0.00489 0.0150  
sex   -1.69703 0.4609  
diseaseGN  0.17980 0.5447  
diseaseAN  0.39283 0.5447  
diseasePKD-1.13630 0.8250  
frailty(id, dist = gauss  
  se2Chisq DF  
age   0.0106  0.11  1.0
sex   0.3617 13.56  1.0
diseaseGN 0.3927  0.11  1.0
diseaseAN 0.3982  0.52  1.0
diseasePKD0.6173  1.90  1.0
frailty(id, dist = gauss17.89 12.1
  p  
age   0.74000
sex   0.00023
diseaseGN 0.74000
diseaseAN 0.47000
diseasePKD0.17000
frailty(id, dist = gauss 0.12000

Iterations: 6 outer, 30 Newton-Raphson
 Variance of random effect= 0.493 
Degrees of freedom for terms=  0.5  0.6  1.7 12.1 
Likelihood ratio test=47.5  on 14.9 df, p=2.82e-05  n=
76 
 
##

Thank you for your time.
Thanks in advance.

Mohammad Ehsanul Karim
wildscop at yahoo dot com
Institute of Statistical Research and Training
University of Dhaka

__
R-help@stat.math.ethz.ch mailing list
https://stat.ethz.ch/mailman/listinfo/r-help
PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.


Re: [R] Extracting approximate Wald test (Chisq) from coxph(..frailty)

2007-04-17 Thread Paul Artes

Assign the output of coxph to some object, and use the $ extractor function
to obtain what you need.

ie:
rtfm - coxph(formula = Surv(time, status) ~ age + sex +  disease +
frailty(id, dist = gauss), data = kidney) 
Age - coef(rtfm)[age]
OR
Sex - rtfm$coef[sex]

Hope this helps.

Paul


Mohammad Ehsanul Karim wrote:
 
 Dear List,
 
 How do I extract the approximate Wald test for the
 frailty (in the following example 17.89 value)?
 
 What about the P-values, other Chisq, DF, se(coef) and
 se2? How can they be extracted?
 
 ##
 kfitm1
 Call:
 coxph(formula = Surv(time, status) ~ age + sex +
 disease + frailty(id, 
 dist = gauss), data = kidney)
 
   coef se(coef)
 age0.00489 0.0150  
 sex   -1.69703 0.4609  
 diseaseGN  0.17980 0.5447  
 diseaseAN  0.39283 0.5447  
 diseasePKD-1.13630 0.8250  
 frailty(id, dist = gauss  
   se2Chisq DF  
 age   0.0106  0.11  1.0
 sex   0.3617 13.56  1.0
 diseaseGN 0.3927  0.11  1.0
 diseaseAN 0.3982  0.52  1.0
 diseasePKD0.6173  1.90  1.0
 frailty(id, dist = gauss17.89 12.1
   p  
 age   0.74000
 sex   0.00023
 diseaseGN 0.74000
 diseaseAN 0.47000
 diseasePKD0.17000
 frailty(id, dist = gauss 0.12000
 
 Iterations: 6 outer, 30 Newton-Raphson
  Variance of random effect= 0.493 
 Degrees of freedom for terms=  0.5  0.6  1.7 12.1 
 Likelihood ratio test=47.5  on 14.9 df, p=2.82e-05  n=
 76 
  
 ##
 
 Thank you for your time.
 Thanks in advance.
 
 Mohammad Ehsanul Karim
 wildscop at yahoo dot com
 Institute of Statistical Research and Training
 University of Dhaka
 
 __
 R-help@stat.math.ethz.ch mailing list
 https://stat.ethz.ch/mailman/listinfo/r-help
 PLEASE do read the posting guide
 http://www.R-project.org/posting-guide.html
 and provide commented, minimal, self-contained, reproducible code.
 
 

-- 
View this message in context: 
http://www.nabble.com/Extracting-approximate-Wald-test-%28Chisq%29-from-coxph%28..frailty%29-tf3589257.html#a10038426
Sent from the R help mailing list archive at Nabble.com.

__
R-help@stat.math.ethz.ch mailing list
https://stat.ethz.ch/mailman/listinfo/r-help
PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.


Re: [R] Extracting approximate Wald test (Chisq) from coxph(..frailty)

2007-04-17 Thread Charles C. Berry
On Tue, 17 Apr 2007, Mohammad Ehsanul Karim wrote:

 Dear List,

 How do I extract the approximate Wald test for the
 frailty (in the following example 17.89 value)?


The example you give silently invokes print.coxph() to produce that 
output.

You _can_ use

tmp - capture.output( print( your example ) )

and then further process tmp.

A _better_ solution for most purposes is to look at the object produced by 
coxph() and figure out how to calculate the Wald statistic from that 
object. See

?coxph.object

and
?str

Another tactic is to look at how print.coxph() does its work and use the 
code in it to produce just the output you desire. Look at

page( survival:::print.coxph, print )




 What about the P-values, other Chisq, DF, se(coef) and
 se2? How can they be extracted?

 ##
 kfitm1
 Call:
 coxph(formula = Surv(time, status) ~ age + sex +
 disease + frailty(id,
dist = gauss), data = kidney)

  coef se(coef)
 age0.00489 0.0150
 sex   -1.69703 0.4609
 diseaseGN  0.17980 0.5447
 diseaseAN  0.39283 0.5447
 diseasePKD-1.13630 0.8250
 frailty(id, dist = gauss
  se2Chisq DF
 age   0.0106  0.11  1.0
 sex   0.3617 13.56  1.0
 diseaseGN 0.3927  0.11  1.0
 diseaseAN 0.3982  0.52  1.0
 diseasePKD0.6173  1.90  1.0
 frailty(id, dist = gauss17.89 12.1
  p
 age   0.74000
 sex   0.00023
 diseaseGN 0.74000
 diseaseAN 0.47000
 diseasePKD0.17000
 frailty(id, dist = gauss 0.12000

 Iterations: 6 outer, 30 Newton-Raphson
 Variance of random effect= 0.493
 Degrees of freedom for terms=  0.5  0.6  1.7 12.1
 Likelihood ratio test=47.5  on 14.9 df, p=2.82e-05  n=
 76

 ##

 Thank you for your time.
 Thanks in advance.

 Mohammad Ehsanul Karim
 wildscop at yahoo dot com
 Institute of Statistical Research and Training
 University of Dhaka

 __
 R-help@stat.math.ethz.ch mailing list
 https://stat.ethz.ch/mailman/listinfo/r-help
 PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
 and provide commented, minimal, self-contained, reproducible code.


Charles C. Berry(858) 534-2098
  Dept of Family/Preventive Medicine
E mailto:[EMAIL PROTECTED]   UC San Diego
http://biostat.ucsd.edu/~cberry/ La Jolla, San Diego 92093-0901

__
R-help@stat.math.ethz.ch mailing list
https://stat.ethz.ch/mailman/listinfo/r-help
PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.


Re: [R] Extracting approximate Wald test (Chisq) from coxph(..frailty)

2007-04-17 Thread Mohammad Ehsanul Karim
Dear list,

I need to extract the approximate Wald test (Chisq) so
that I can put it in a loop. str seemed like a great
idea, but I cannot seem to find the approximate Wald
test for frailty (in the example data below: 17.89 and
its p-value 0.12000) there. I cannot seem to find it
in capture.output either as numeric form. Do I need to
modify some given values? If yes, please give me a
clue for the example:

library(survival)
kfitm1-coxph(formula = Surv(time, status) ~ age +
sex +disease + frailty(id, dist = gauss), 
data = kidney)
str(kfitm1)
capture.output( print(kfitm1) )


Mohammad Ehsanul Karim (R - 2.3.1 on windows)
wildscop at yahoo dot com
Institute of Statistical Research and Training
University of Dhaka



On Tue, 17 Apr 2007, Mohammad Ehsanul Karim wrote:
You _can_ use   tmp - capture.output( print( your
example ) ) and then further process tmp. A _better_
solution for most purposes is to look at the object
produced by coxph() and figure out how to calculate
the Wald statistic from that 
object. See ?coxph.object and   ?str
Another tactic is to look at how print.coxph() does
its work and use the code in it to produce just the
output you desire. Look at page(
survival:::print.coxph, print )

Assign the output of coxph to some object, and use the
$ extractor function to obtain what you need. ie:
rtfm - coxph(formula = Surv(time, status) ~ age + sex
+  disease + frailty(id, dist = gauss), data =
kidney) 
Age - coef(rtfm)[age]
OR
Sex - rtfm$coef[sex]

Mohammad Ehsanul Karim wrote:
 Dear List,
 How do I extract the approximate Wald test for the
 frailty (in the following example 17.89 value)?
 What about the P-values, other Chisq, DF, se(coef)
and  se2? How can they be extracted?
##
kfitm1
 Call:
 coxph(formula = Surv(time, status) ~ age + sex +
 disease + frailty(id, dist = gauss), data =
kidney)
 
   coef se(coef)
 age0.00489 0.0150  
 sex   -1.69703 0.4609  
 diseaseGN  0.17980 0.5447  
 diseaseAN  0.39283 0.5447  
 diseasePKD-1.13630 0.8250  
 frailty(id, dist = gauss  
   se2Chisq DF  
 age   0.0106  0.11  1.0
 sex   0.3617 13.56  1.0
 diseaseGN 0.3927  0.11  1.0
 diseaseAN 0.3982  0.52  1.0
 diseasePKD0.6173  1.90  1.0
 frailty(id, dist = gauss17.89 12.1
   p  
 age   0.74000
 sex   0.00023
 diseaseGN 0.74000
 diseaseAN 0.47000
 diseasePKD0.17000
 frailty(id, dist = gauss 0.12000
 
 Iterations: 6 outer, 30 Newton-Raphson
  Variance of random effect= 0.493 
 Degrees of freedom for terms=  0.5  0.6  1.7 12.1 
 Likelihood ratio test=47.5  on 14.9 df, p=2.82e-05 
n=
 76

__
R-help@stat.math.ethz.ch mailing list
https://stat.ethz.ch/mailman/listinfo/r-help
PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.